frontsim ug

FrontSim

User Guide

2009.1

Proprietary NoticeCopyright © 1988-2009 Schlumberger. All rights reserved.

No part of this document may be reproduced, stored in an information retrieval system, or translated or retransmitted in any form or by anymeans, electronic or mechanical, including photocopying and recording, without the prior written permission of the copyright owner.

Use of this product is governed by the License Agreement. Schlumberger makes no warranties, express, implied, or statutory, with respectto the product described herein and disclaims without limitation any warranties of merchantability or fitness for a particular purpose.

Patent informationSchlumberger ECLIPSE reservoir simulation software is protected by US Patents 6,018,497, 6,078,869 and 6,106,561, and UK PatentsGB 2,326,747 B and GB 2,336,008 B. Patents pending. Schlumberger FrontSim reservoir simulation software is protected by US Patent2004/0015295A1.

Service mark informationThe following are all service marks of Schlumberger:

The Calculator, Charisma, ConPac, ECLIPSE 100, ECLIPSE 200, ECLIPSE 300, ECLIPSE 500, ECLIPSE Office, EDIT, Extract, Fill,Finder, FloGeo, FloGrid, FloViz, FrontSim, GeoFrame, GRAF, GRID, GridSim, Nodal, NWM, Open-ECLIPSE, PetraGrid, PIPESIM,PIPESIM FPT, PIPESIM GOAL, PlanOpt, Prodman, Pseudo, PVTi, RTView, SCAL, Schedule, SimOpt, VFPi, Weltest 200.

Trademark informationSilicon Graphics and IRIX are registered trademarks of Silicon Graphics, Inc. OpenGL® and the oval logo are trademarks or registeredtrademarks of Silicon Graphics, Inc. in the United States and/or other countries worldwide. OpenInventor and WebSpace are trademarksof Silicon Graphics, Inc. IBM, AIX are registered trademarks of International Business Machines Corporation. Sun, SPARC, Solaris, Ultraand UltraSPARC are trademarks or registered trademarks of Sun Microsystems, Inc. Macintosh is a registered trademark of AppleComputer, Inc. UNIX is a registered trademark of UNIX System Laboratories. Motif is a registered trademark of the Open SoftwareFoundation, Inc. The X Window System and X11 are registered trademarks of the Massachusetts Institute of Technology. PostScript andEncapsulated PostScript are registered trademarks of Adobe Systems, Inc. OpenWorks and VIP are registered trademarks of LandmarkGraphics Corporation. Lotus, 1-2-3 and Symphony are registered trademarks of Lotus Development Corporation. Microsoft, Windows,Windows NT, Windows 95, Windows 98, Windows 2000, Windows XP, Internet Explorer, Intellimouse and PowerPoint are eitherregistered trademarks or trademarks of Microsoft Corporation in the United States and/or other countries. Netscape is a registeredtrademark of Netscape Communications Corporation. AVS is a registered trademark of AVS Inc. ZEH is a registered trademark of ZEHGraphics Systems. Ghostscript and GSview are Copyright of Aladdin Enterprises, CA. GNU Ghostscript is Copyright of the Free SoftwareFoundation, Inc. Linux is Copyright of the Free Software Foundation, Inc. IRAP is Copyright of Roxar Technologies. LSF is a registeredtrademark of Platform Computing Corporation, Canada. VISAGE is a registered trademark of VIPS Ltd. Cosmo is a trademark andPLATINUM technology is a registered trademark of PLATINUM technology, inc. PEBI is a trademark of Veritas DGC Inc./HOT EngineeringGmbH. Stratamodel is a trademark of Landmark Graphics Corporation. GLOBEtrotter, FLEXlm and SAMreport are registered trademarksof GLOBEtrotter Software, Inc. CrystalEyes is a trademark of StereoGraphics Corporation. Tektronix is a registered trade mark ofTektronix, Inc. GOCAD and JACTA are trademarks of T-Surf. Myrinet is a trade name of Myricom, Inc. This product may include softwaredeveloped by the Apache Software Foundation (http://www.apache.org). Copyright (c) 1999-2001 The Apache Software Foundation. Allrights reserved. MPI/Pro is a registered trademark of MPI Software Technology, Inc. The TGS logo is a trademark of TGS, Inc. POSC, thePOSC logo and Epicentre are registered trademarks of Petrotechnical Open Standards Consortium, Inc. Red Hat is a registeredtrademeak of Red Hat, Inc. This product may include software developed using LAPACK (http://www.netlib.org/lapack/), which is copyrightof its authors. Scali is a trademark of Scali Inc. Intel is a registered trademark of Intel Corporation.

FrontSim User Guide Table of Contents

3

Table of ContentsList of Figures ..... ...................................................................................................................................................................9List of Tables ...... .................................................................................................................................................................10

Chapter 1 - Developments for 2009.1............................................................................................ 11New Features ..... .................................................................................................................................................................11

Chapter 2 - Introduction to FrontSim............................................................................................ 15Description.......... .................................................................................................................................................................15Streamline Simulation...........................................................................................................................................................16Front tracking...... .................................................................................................................................................................17Major FrontSim Features......................................................................................................................................................18

Chapter 3 - Programs and Files..................................................................................................... 19Programs ............ .................................................................................................................................................................19Files .................... .................................................................................................................................................................20Keywords............ .................................................................................................................................................................24

Chapter 4 - Getting Started ............................................................................................................ 25Data file sections .................................................................................................................................................................25Coordinate and grid system..................................................................................................................................................27Phase properties .................................................................................................................................................................29Well control ......... .................................................................................................................................................................30Optimizing Performance .......................................................................................................................................................32Simulation output .................................................................................................................................................................35Sample case data file ...........................................................................................................................................................45

Chapter 5 - Data File Overview ...................................................................................................... 49Introduction......... .................................................................................................................................................................49RUNSPEC section................................................................................................................................................................50GRID section ...... .................................................................................................................................................................51EDIT section ....... .................................................................................................................................................................54PROPS section... .................................................................................................................................................................55REGIONS section.................................................................................................................................................................58SOLUTION section...............................................................................................................................................................59SUMMARY section...............................................................................................................................................................60SCHEDULE section..............................................................................................................................................................73

Chapter 6 - Keywords ..................................................................................................................... 77ACF: Acentric factor ............................................................................................................................................................ 77ACTNUM: Active grid block identification ............................................................................................................................ 78ADD: Adds a constant to the specified array in current box ................................................................................................ 79AQANTRC: Sets initial tracer concentrations for analytic aquifers ...................................................................................... 81AQUANCON: Specifies connection data for analytic aquifers............................................................................................. 82AQUCT: Specifies the property data for Carter-Tracy aquifers ........................................................................................... 84AQUFETP: Specifies the property data for Fetkovich aquifers............................................................................................ 86AQUFLUX: Specifies a constant flux aquifer ....................................................................................................................... 88AQUCON: Specifies connection data for numerical aquifers .............................................................................................. 89AQUNUM: Assigns a numerical aquifer to a block .............................................................................................................. 91AQUTAB: Influence function tables for Carter-Tracy aquifers ............................................................................................. 93BIC: Binary interaction coefficients ...................................................................................................................................... 94BOX: Re-defines the current input box................................................................................................................................ 95

4 FrontSim User GuideTable of Contents

CARFIN: Specifies a cartesian local grid refinement ........................................................................................................... 96CECON: Economic limits for production well connections................................................................................................... 98CECONINJ: Economic limits for injection well connections............................................................................................... 100CNAMES: Component names ........................................................................................................................................... 102COMPDAT: Well completion specification data................................................................................................................. 103COMPDATL: Completion data for wells in local grids........................................................................................................ 106COMPLUMP: Lumps connections into completions .......................................................................................................... 107COMPORD: Defines the ordering of well connections ...................................................................................................... 109COMPS: Requests compositional mode............................................................................................................................ 111COORD: Coordinate lines.................................................................................................................................................. 112COORDXYZ: X, Y, Z coordinates of the grid ..................................................................................................................... 113COPY: Copies data from one array to another .................................................................................................................. 114DATES: Advances simulator to specified report date(s).................................................................................................... 116DATUM: Datum depth for output of depth corrected pressures......................................................................................... 117DENSITY: Fluid densities at surface conditions ................................................................................................................ 118DEPTHZ: Depth to all top layer nodes............................................................................................................................... 119DIMENS: Specifies the dimensions of the grid .................................................................................................................. 120DPGRID: Use matrix cell grid data for fracture cells.......................................................................................................... 121DRSDT: Maximum rate of increase of solution GOR......................................................................................................... 122DPNUM: Identifies extent of dual porosity region .............................................................................................................. 123DRVDT: Maximum rate of increase of vapor OGR............................................................................................................ 124DUALPORO: Run is to use dual porosity .......................................................................................................................... 125DUMPFLUX: Makes a full-field run write a flux file ............................................................................................................ 126DXV/DYV: Grid block sizes in X/Y direction (vector) ......................................................................................................... 127DZV: Z-direction grid block sizes (vector) .......................................................................................................................... 128EDITNNC: Change a non-neighbor connection................................................................................................................. 129END: Logical end of input file............................................................................................................................................. 130ENDBOX: Reset current input box to encompass the entire grid ...................................................................................... 131ENDFIN: Terminates data for a local grid refinement ........................................................................................................ 132ENDINC: Logical end of include file................................................................................................................................... 133ENDNUM: End point scaling versus depth region numbers .............................................................................................. 134ENDSCALE: Use saturation table end-point scaling ......................................................................................................... 135ENKRVD: Relative permeability end point versus depth tables......................................................................................... 136ENPTVD: Saturation end point versus depth tables.......................................................................................................... 138EOS: Specify which equation of state is to be used .......................................................................................................... 140EPSDEBUG: Controls debug for end-point scaling option ................................................................................................ 141EQLNUM: Equilibration region numbers............................................................................................................................ 143EQUALS: Set array to a constant in current box ............................................................................................................... 144EQUIL: Equilibration data specification.............................................................................................................................. 146EXCEL: Requests run summary output to be in Excel format ........................................................................................... 150FAULTS: Specifies faults for later editing .......................................................................................................................... 151FDM9PNT: Specify finite difference method...................................................................................................................... 153FIELD: Field units are to be used ...................................................................................................................................... 154FIPNUM: Fluid-in-place region numbers............................................................................................................................ 155FLUXNUM: Identifies extent of each flux region................................................................................................................ 156FLUXSIDE: Flux boundary condition ................................................................................................................................. 158FLUXTYPE: Specify type of flux boundary condition......................................................................................................... 160FRONTSIM: Accept only FrontSim keywords.................................................................................................................... 161FSSOLVE: Specifies equation solver ................................................................................................................................ 162FSWEAKW: Reducing material balance errors ................................................................................................................. 163GADJUST: Corrects diagonal permeability tensor............................................................................................................. 164GAS: Run contains GAS.................................................................................................................................................... 165GCONINJE: Injection rate controls/limits for groups/field .................................................................................................. 166GCONPROD: Production rate controls/limits for groups/field............................................................................................ 168GECON: Economic limit data for groups and the field....................................................................................................... 170GEOFLOFS: Setup Simple Simulations for Flow Analysis on Geologic Models ............................................................... 172GOCADGRI: Recognize stratigraphic grid......................................................................................................................... 178GOCADOUT: JACTA-compatible output file to be generated ........................................................................................... 179GRAVITY: Fluid gravities at surface conditions ................................................................................................................. 180


5

GRIDFILE: Controls output of the Grid geometry file ........................................................................................................ 181GUIDERAT: Specifies general formula for guide rates...................................................................................................... 182HEATCAP: Heat capacity for rock and fluid ...................................................................................................................... 183HXFIN: Local grid size ratios in x-direction........................................................................................................................ 184HYFIN: Local grid size ratios in y-direction........................................................................................................................ 185HZFIN: Local grid size ratios in z-direction ........................................................................................................................ 186INCLUDE: Include the contents of another named file ...................................................................................................... 187INIT: Requests output of an INIT file ................................................................................................................................. 188JFUNC: Activates the Leverett J-function option............................................................................................................... 189KRG: Scaled end point gas relative permeabilities............................................................................................................ 191KRGR: Scaled end point gas relative permeabilities ......................................................................................................... 193KRO: Scaled end point oil relative permeabilities.............................................................................................................. 195KRORG: Scaled end point oil relative permeabilities ........................................................................................................ 197KRORW: Scaled end point oil relative permeabilities........................................................................................................ 199KRW: Scaled end point water relative permeabilities ........................................................................................................ 201KRWR: Scaled end point water relative permeabilities ..................................................................................................... 203MAPAXES: Input of pre-processor map origin .................................................................................................................. 205MAPUNITS: Specifies units used for MAPAXES data....................................................................................................... 206MAXSTEP: Sets a maximum value for subsequent timesteps .......................................................................................... 207METRIC: Metric units are to be used................................................................................................................................. 208MINPV: Sets a minimum pore volume a cell must have to be active ................................................................................ 209MINSTEP: Sets a minimum value for subsequent timesteps ............................................................................................ 210MISUPPLY: Solvent supply rate........................................................................................................................................ 211MSGFILE: Generate an XML-formatted message file ....................................................................................................... 212MULTFLT: Modifies the transmissibility across a named fault .......................................................................................... 213MULTIPLY: Multiply array by a constant in current box..................................................................................................... 214MULTNUM: Defines regions for applying inter-region transmissibility multipliers ............................................................. 216MULTPV: Pore volume multipliers..................................................................................................................................... 217MULTREGT: Multiplies the transmissibility between flux or MULTNUM regions .............................................................. 218MULTX: Transmissibility multipliers in X-direction............................................................................................................. 220MULTX-: Transmissibility multipliers in the negative X-direction ....................................................................................... 221MULTY: Transmissibility multipliers in Y-direction............................................................................................................. 222MULTY-: Transmissibility multipliers in the negative Y-direction ....................................................................................... 223MULTZ: Transmissibility multipliers in Z-direction ............................................................................................................. 224MULTZ-: Transmissibility multipliers in the negative Z-direction ....................................................................................... 225MW: Molecular weights...................................................................................................................................................... 226NEXTSTEP: Sets a maximum value for the next timestep................................................................................................ 227NODPPM: No dual porosity permeability multiplier ........................................................................................................... 228NOGRAV: Sets gravity to zero .......................................................................................................................................... 229NOSIM: Turn off simulation ............................................................................................................................................... 230NTG: Net to gross thickness ratios .................................................................................................................................... 231NTRNSAVE: Turns off saving transmissibilities in memory............................................................................................... 232NXFIN: Number of local cells in each global cell of an LGR in X direction........................................................................ 233NYFIN: Number of local cells in each global cell of an LGR in Y direction........................................................................ 234NZFIN: Number of local cells in each global cell of an LGR in Z direction ........................................................................ 235OIL: Indicates that the run contains oil .............................................................................................................................. 236OMEGAA: Overrides default Ωa values............................................................................................................................. 237OMEGAB: Overrides default Ωb values............................................................................................................................. 238OPTIONFS: Activates special program options................................................................................................................. 239PARACHOR: Component parachors................................................................................................................................. 246PBUB: Initial bubble point pressure................................................................................................................................... 247PBVD: Bubble point versus depth tables for equilibration ................................................................................................. 248PCRIT: Critical pressures .................................................................................................................................................. 249PCW: Scaled maximum water capillary pressures ............................................................................................................ 250PDEW: Initial dew point pressure ...................................................................................................................................... 251PDVD: Dew point versus depth tables for equilibration ..................................................................................................... 252PERFORM: FrontSim performance tuning ........................................................................................................................ 253PERMX: Specifies X-permeability values.......................................................................................................................... 254PERMXY/ZY: Specifies off-diagonal tensor permeability coefficients ............................................................................... 255


PERMY: Specifies Y-permeability values .......................................................................................................................... 256PERMZ: Specifies Z-permeability values........................................................................................................................... 257PETGRID: Recognize grid and properties in Open Petrel Format..................................................................................... 258PINCH: Generates connections across pinched-out layers............................................................................................... 259PINCHNUM: Identifies pinchout regions............................................................................................................................ 261PINCHREG: Generates connections across pinched-out layers within regions ................................................................ 262PINCHXY: Generates horizontal pinchout connections..................................................................................................... 264PNODE: Pressure boundary condition .............................................................................................................................. 265PORO: Specifies the grid block porosity values ................................................................................................................ 266PORV: Specifies the grid block pore volumes ................................................................................................................... 267PPCWMAX: Limits the calculated PCW values when SWATINIT is used......................................................................... 268PRCORR: Request modified Peng-Robinson EoS............................................................................................................ 269PRESSURE: Initial pressures............................................................................................................................................ 270PRODLIM: Water and gas handling limit ........................................................................................................................... 271PSIDE: Pressure boundary condition ................................................................................................................................ 272PSIDEH: Hydrostatic pressure boundary condition ........................................................................................................... 273PVDG: PVT properties of dry gas (no vaporized oil) ......................................................................................................... 274PVDO: PVT properties of dead oil ..................................................................................................................................... 275PVTG: PVT properties of wet gas (with vaporized oil)....................................................................................................... 276PVTNUM: PVT region numbers......................................................................................................................................... 278PVTO: PVT properties of live oil (with dissolved gas)........................................................................................................ 279PVTW: Water PVT functions.............................................................................................................................................. 281RANKING: Ranking of solvent allocation........................................................................................................................... 282RANKWELL: Ranked well list ............................................................................................................................................ 284REFINE: Initiates data input for a named local grid ........................................................................................................... 288RESTART: Read solution from a restart file ...................................................................................................................... 290ROCK: Rock compressibility.............................................................................................................................................. 292ROCKNUM: Rock compaction table region numbers ........................................................................................................ 293RPTALLOC: Controls on output to the .ALN file ................................................................................................................ 294RPTLINFS: Sets report frequency for line graph output .................................................................................................... 296RPTPRINT: Control printed simulation reports .................................................................................................................. 297RPTRST: Controls on output to the RESTART file............................................................................................................ 298RPTSCHED: Controls on output from SCHEDULE section............................................................................................... 301RPTSLN: Controls on output to the SLN file...................................................................................................................... 303RPTSOL: Controls output from SOLUTION section .......................................................................................................... 305RS: Initial solution gas-oil ratios......................................................................................................................................... 306RSCONSTT: Sets a constant Rs value for each dead oil PVT table ................................................................................. 307RSVD: Rs versus depth tables for equilibration ................................................................................................................. 308RTEMP: Initial reservoir temperature................................................................................................................................. 309RUNSUM: Requests tabulated output of SUMMARY data to separate file ....................................................................... 310RV: Initial vapor oil-gas ratios ............................................................................................................................................ 311RVCONSTT: Sets a constant Rv value for each dry gas PVT table .................................................................................. 312RVVD: Rv versus depth tables for equilibration ................................................................................................................. 313SATNUM: Saturation function region numbers.................................................................................................................. 314SCALECRS: Controls the end point scaling method ......................................................................................................... 315SEPARATE: Requests run summary output to separate RSM file .................................................................................... 316SGAS: Initial gas saturations ............................................................................................................................................. 317SGCR: Scaled critical gas saturations ............................................................................................................................... 318SGFN: Gas saturation functions ........................................................................................................................................ 319SGL: Scaled connate gas saturations................................................................................................................................ 320SGOF: Gas/oil saturation functions versus gas saturation ................................................................................................ 321SGU: Scaled saturation table maximum gas saturations................................................................................................... 323SIGMA: Dual porosity matrix-fracture coupling.................................................................................................................. 324SIGMAV: Dual porosity matrix-fracture coupling ............................................................................................................... 325SKIPREST: Skip subsequent keywords until the restart time............................................................................................ 326SOF2: Oil saturation functions (2-phase)........................................................................................................................... 327SOF3: Oil saturation functions (3-phase)........................................................................................................................... 328SOGCR: Scaled critical oil-in-gas saturations ................................................................................................................... 329SOLVSLUG: Solvent slug allocation.................................................................................................................................. 330


7

SOWCR: Scaled critical oil-in-water saturations................................................................................................................ 332SSHIFT: Equation of state shift parameters ...................................................................................................................... 333START: Specifies a start date ........................................................................................................................................... 334STCOND: Specify standard conditions.............................................................................................................................. 335STONE1: Request Stone three-phase oil relative permeability model .............................................................................. 336STONE2: Request Stone three-phase oil relative permeability model .............................................................................. 337SWAT: Initial water saturations.......................................................................................................................................... 338SWATINIT: Initial water saturations for capillary pressure scaling .................................................................................... 339SWCR: Scaled critical water saturations ........................................................................................................................... 341SWFN: Water saturation functions .................................................................................................................................... 342SWL: Scaled connate water saturations............................................................................................................................ 343SWOF: Water / oil saturation functions versus water saturation ....................................................................................... 344SWU: Scaled saturation table maximum water saturations............................................................................................... 346TABDIMS: Table dimensions............................................................................................................................................. 347TAD: Adsorption function for tracer ................................................................................................................................... 349TADE: Adsorption - IOR tracer .......................................................................................................................................... 353TBLK: Initial tracer concentrations..................................................................................................................................... 355TCRIT: Critical temperatures............................................................................................................................................. 356THICKZ: Layer thickness in z direction.............................................................................................................................. 357THREADFS: Set maximum number of threads for a FrontSim run ................................................................................... 358TIADS: Initial tracer adsorbed............................................................................................................................................ 359TITLE: Specify run title ...................................................................................................................................................... 360TPAIRS: Tracer pair lookup table ...................................................................................................................................... 361TPFA: Fraction of pore volume flooded by the tracer ........................................................................................................ 362TPFV: Fraction of pore volume flooded by the tracer by cell............................................................................................. 363TPVT: Tracer PVT ............................................................................................................................................................. 364TRACER: Set up tracers.................................................................................................................................................... 366TRANX: X-direction transmissibility values........................................................................................................................ 367TRANY: Y-direction transmissibility values........................................................................................................................ 368TRANZ: Z-direction transmissibility values ........................................................................................................................ 369TREFFIC: Table of IOR mobilization curves...................................................................................................................... 370TSCRITFS: Describes user control of time stepping algorithm ......................................................................................... 374TSTEP: Advances simulator to new report time(s)............................................................................................................ 377TUNEFS1D: Tuning options for the 3-phase 1D solver..................................................................................................... 378TUNEFSPR: Sets simulator control parameters................................................................................................................ 380TUNEFSSA: Tuning options for the saturation solver ....................................................................................................... 381UNIFIN: Indicates that input files are unified ..................................................................................................................... 383UNIFOUT: Multiple/Unified Output Files............................................................................................................................ 384VCRIT: Critical volumes..................................................................................................................................................... 385VCRITVIS: Critical volumes for viscosity calculations ....................................................................................................... 386VFPINJ: Inputs a VFP table for injection wells .................................................................................................................. 387VFPPROD: Inputs a VFP table for production wells.......................................................................................................... 390WATER: Run contains water ............................................................................................................................................. 395WCONHIST: Observed rates for history matching wells ................................................................................................... 396WCONINJ: Injection well control data, with no group control ............................................................................................ 399WCONINJE: Control data for injection wells...................................................................................................................... 401WCONINJH: Observed rates for history matching injection wells ..................................................................................... 404WCONINJP: Control data for pattern flood injection wells................................................................................................. 406WCONPAT: Injection Rate Optimization ........................................................................................................................... 409WCONPEND: Switch Off Injection Rate Optimization ....................................................................................................... 411WCONPROD: Control data for production wells ............................................................................................................... 412WECON: Economic limit data for production wells............................................................................................................ 414WECONINJ: Economic limit data for injection wells .......................................................................................................... 416WEFAC: Sets well efficiency factors (for downtime).......................................................................................................... 417WELLDIMS: Well dimension data...................................................................................................................................... 419WELLSTRE: Set composition of injection gas stream....................................................................................................... 420WELOPEN: Shuts or reopens wells or well connections................................................................................................... 421WELPI: Sets well productivity/injectivity index values ....................................................................................................... 423WELSPECL: General specification data for wells in local grids ........................................................................................ 424


WELSPECS: General specification data for wells ............................................................................................................. 425WELSTRDN: Stream density for well ................................................................................................................................ 427WELTARG: Resets a well operating target or limit ............................................................................................................ 428WFRICTN: Designates a well as a friction well.................................................................................................................. 430WINJGAS: Specify the nature of injection gas................................................................................................................... 433WLIST: Sets up lists of well names.................................................................................................................................... 434WPAVE: Well block average pressure controls ................................................................................................................. 436WPAVEDEP: Reference depth for well block average pressure calculation ..................................................................... 438WPIMULT: Multiplies well connection factors by a given value......................................................................................... 439WRFTPLT: Requests output of well RFT, PLT and segment data to the RFT file............................................................. 441WSOLVENT: Sets solvent fraction for gas injection wells ................................................................................................. 443WTEMP: Sets the temperature of a water injection well.................................................................................................... 444WTEST: Instructions for periodic testing of closed wells ................................................................................................... 445WTMULT: Multiplies a well operating target or limit........................................................................................................... 447WTRACER: Sets tracer concentrations for injection wells................................................................................................. 448ZCORN: Depths of grid block corners ............................................................................................................................... 449ZCRIT: Critical Z-factors .................................................................................................................................................... 450ZCRITVIS: Critical Z-factors for viscosity calculations....................................................................................................... 451ZMF: Specifies cell initial total composition explicitly......................................................................................................... 452ZMFVD: Total composition with respect to depth tables.................................................................................................... 453

Chapter 7 - Tutorials ..................................................................................................................... 455Introduction ......... ...............................................................................................................................................................455Workflow for a Simulation Case..........................................................................................................................................456

Appendix A - Retired Keywords .................................................................................................. 471Keywords retired in 2003A release.....................................................................................................................................471Keywords retired in 2002A release.....................................................................................................................................472

Appendix B - Units........................................................................................................................ 473The unit conventions...........................................................................................................................................................473Conversion factors..............................................................................................................................................................475

Appendix C - Bibliography........................................................................................................... 477

Appendix D - Index ....................................................................................................................... 481

FrontSim User Guide List of Figures

9

List of FiguresFigure 3.1 .......... Programs and files overview...................................................................................................................20Figure 4.1 .......... Alternative ways to define the grid ..........................................................................................................28Figure 6.1 .......... Effect of Item 9 on saturation definition ................................................................................................148Figure 6.2 .......... Reservoir boundaries............................................................................................................................158Figure 6.3 .......... Symmetrical streamlines in a cell .........................................................................................................163Figure 6.4 .......... Meanings of the MAPAXES keyword entries........................................................................................205Figure 6.5 .......... Grid boundaries ....................................................................................................................................272Figure 6.6 .......... Grid boundaries ....................................................................................................................................273Figure 6.7 .......... Adsorption isotherm for effective solvent ..............................................................................................350Figure 6.8 .......... Adsorption isotherm for ineffective solvent ...........................................................................................350Figure 6.9 .......... Langmuir model ....................................................................................................................................352Figure 7.1 .......... Oil Saturation at the end of production history......................................................................................461Figure 7.2 .......... Plot of dimensionless oil recovery and water cut for production ..........................................................462Figure 7.3 .......... Well Oil Production Rate and Water Cut for Prediction run ..................................................................465Figure 7.4 .......... Streamlines at the end of prediction colored by Time of Flight .............................................................467

10 FrontSim User GuideList of Tables

List of TablesTable 1.1 New RUNSPEC keywords .......................................................................................................................13Table 1.2 Summary Vectors ....................................................................................................................................13Table 1.3 Altered keywords .....................................................................................................................................13Table 4.1 Data file sections......................................................................................................................................25Table 4.2 Production parameters (fluids in place and volumetric flows) ..................................................................39Table 4.3 Material Balance Error reports (MBE)......................................................................................................40Table 4.4 Other ........................................................................................................................................................40Table 5.1 RUNSPEC keywords ...............................................................................................................................50Table 5.2 GRID keywords........................................................................................................................................51Table 5.3 EDIT keywords.........................................................................................................................................54Table 5.4 PROPS keywords ....................................................................................................................................55Table 5.5 REGIONS keywords ................................................................................................................................58Table 5.6 SOLUTION keywords ..............................................................................................................................59Table 5.7 Well and group oil flows ...........................................................................................................................60Table 5.8 Well and group water flows......................................................................................................................60Table 5.9 Well and group gas flows.........................................................................................................................61Table 5.10 Well and group liquid flows ......................................................................................................................61Table 5.11 Well and group reservoir volume flows ....................................................................................................61Table 5.12 Well and group production ratios .............................................................................................................62Table 5.13 Well pressures etc. ..................................................................................................................................62Table 5.14 Miscellaneous quantities..........................................................................................................................62Table 5.15 Tracer Grid quantities ..............................................................................................................................63Table 5.16 Tracer Well quantities ..............................................................................................................................63Table 5.17 IOR Oil Rates...........................................................................................................................................63Table 5.18 IOR Water Rates......................................................................................................................................63Table 5.19 IOR Gas Rates.........................................................................................................................................63Table 5.20 Compositional quantities..........................................................................................................................64Table 5.21 Analytic aquifer quantities ........................................................................................................................64Table 5.22 Numerical aquifer quantities ....................................................................................................................64Table 5.23 Performance quantities ............................................................................................................................65Table 5.24 Pattern Quantities - valid for both injectors and producers ......................................................................65Table 5.25 Pattern Quantities - valid for injectors only ..............................................................................................65Table 5.26 Temperature Well quantities ....................................................................................................................66Table 5.27 Temperature Grid quantities ....................................................................................................................66Table 5.28 Well and group control modes .................................................................................................................66Table 5.29 Other keywords........................................................................................................................................67Table 5.30 SCHEDULE keywords .............................................................................................................................73Table 6.31 Controls on output to .ALN file ...............................................................................................................294Table 6.32 Controls on Output to the RESTART file ...............................................................................................298Table 6.33 Mnemonics available for RPTSCHED keyword .....................................................................................301Table 6.34 Controls on output to the SLN file ..........................................................................................................303Table A.1 Changed keywords ................................................................................................................................472Table A.2 Keyword significantly changed in 2002A release...................................................................................472Table B.1 A table of the units used for four conventions........................................................................................473Table B.2 Constants used in the four unit conventions ..........................................................................................474Table B.3 Some useful conversion factors.............................................................................................................475

FrontSim User Guide Developments for 2009.1New Features

11

Chapter 1Developments for 2009.1

New Features

Functionality

Screening geologic models• Time of breakthrough (water cut above 0.9) is included as a well property in the fscat file.

To generate this file the keyword GEOFLOFS is needed in the RUNSPEC section.

Water flood management • Zone Rate Control. When lumped completions have been defined the Pattern Flood

Management algorithm will calculate injection rates for the lumped completions. In previous release these rates were accumulated for the well and then applied. In FrontSim 2009.1 these zone based rates can be honoured directly for the lumped completions. Through a new parameter in the WCONPAT keyword you can decide whether to use these zone based rates or the accumulated rate for the well.

• An output file can be generated that includes SCHEDULE keywords with the targets that the PFM algorithm calculated from the time that the WCONPAT keyword was activated to the end of the simulation. This file can later be included in a prediction using either FrontSim or ECLIPSE simulators.

Dual Porosity• Dual Porosity regions. FrontSim 2009.1 now honors the DPNUM keyword. You can, in a

Dual Porosity model, specify regions within the reservoir to be treated as single porosity only.

12 Developments for 2009.1 FrontSim User GuideNew Features

New Reports• PORV (at reservoir conditions) is included in the restart file if the RPORV mnemonic is

specified on the RPTRST keyword

• The keyword RPTALLOC has been slightly changed, new mnemonics have been introduced and others retired.

• When Pattern Flood Management is activated FrontSim will by default export all PFM rates to the PFM_SCHED file using WCONPROD/ WCONINJE keywords. DATES keywords are also included so this file could be automatically be included into ECLIPSE (or FrontSim). By default all wells are controlled by RESV, this can be changed by setting item 66 in the OPTIONFS keyword.

Behavioral changes

Water flood management• Injection Limits for Pattern Flood Management injectors are supported in the same way as

for other injectors. To revert to old behavior, set item 57 in the OPTIONFS keyword.

• Multi Zone Waterflooding is now turned off by default. To turn it on (or to revert to pre-2009.1 behavior) set item 9 in the WCONPAT keyword to ON. Multi Zone will only affect models where the injectors have lumped completions defined.

Well management

• In some cases where the surface rate targets are very sensitive to the saturation solution in previous step the solution might differ slightly from previous releases.

Performance

Multi core parallel Option• In FrontSim 2009.1 the MultiCore shared memory has been further developed and the key

developments are:

• The Streamline Tracing algorithm is parallel

• A parallel Front Tracker for two phase problems

• All parallel features are available on Linux (not Windows PC) only.

See "Multicore Parallel Option" in the "FrontSim Technical Description" for more information about this option.

FrontSim User Guide Developments for 2009.1New Features

13

New Keywords

GRID sectionThe following new keywords have been added:.

SUMMARY sectionThe following new vectors have been added:.

Altered KeywordsThe following keywords have been changed:.

Table 1.1 New RUNSPEC keywords

Keyword DescriptionDPNUM Identify extent of dual porosity region

Table 1.2 Summary Vectors

Vector DescriptionF/G/WOPTH Oil Production Total History

F/G/WGPTH Gas Production Total History

F/G/WWPTH Water Production Total History

F/G/WLPR Liquid Production Rate

F/G/WLPRH Liquid Production Rate History

F/G/WLPT Liquid Production Total

F/G/WLPTH Liquid Production Total History

WMCTL Mode of control for well

FMF*R Field Matrix to Fracture flow rate (* V = total reservoir, W/O/G at surface)

FMF*T Field Matrix to Fracture total (* V = total reservoir, W/O/G at surface)

WPMF*R Pattern Matrix to Fracture flow rate (* V = total reservoir, W/O/G at surface)

WPMF*T Pattern Matrix to Fracture total (* V = total reservoir, W/O/G at surface)

CPMF*RL Pattern Matrix to Fracture flow rate (* V = total reservoir, W/O/G at surface)

CPMF*TL Pattern Matrix to Fracture total (* V = total reservoir, W/O/G at surface)

Table 1.3 Altered keywords

Keyword DescriptionWCONPAT Added item 9 for turning on Multi Zone

RPTRST Added mnemonic RPORV

14 Developments for 2009.1 FrontSim User GuideNew Features

FrontSim User Guide Introduction to FrontSimDescription

15

Chapter 2Introduction to FrontSim

DescriptionFrontSim is a three dimensional, three phase blackoil and compositional streamline simulator. The simulator is based on the IMPES (IMplicit Pressure Explicit Saturation) formulation, as used in finite difference simulators, with the primary difference being that fluid transport or saturation movement is solved along one dimensional streamline space. A highly efficient and non-dispersive front-tracking algorithm is used for two phase, immiscible, e.g. oil-water, displacement. Fluid systems described using black oil and compositional schemes are solved using ECLIPSE 300 fully-implicit, adaptive implicit and IMPES solvers. An explicit Guidons type method is also available for three phase black oil fluids.

The primary strengths of streamline simulation are a) cost-effective modeling and flow simulation on very high resolution and/or extremely large models with multi-million cells, b) reduction of numerical dispersion and grid orientation effects, and c) direct quantification of producer/injector relationships. Invaluable applications ranging from model screening/ranking, uncertainty quantification, history matching to waterflood optimization and IOR feasibility are being done regularly in the petroleum industry using FrontSim.

16 Introduction to FrontSim FrontSim User GuideStreamline Simulation

Streamline SimulationStreamline simulation is based on the same partial differential equations for fluid flow in porous media as used by finite difference simulators. However, streamline simulators use a different computational scheme.

Streamline simulation is many orders of magnitude faster than finite difference simulation for incompressible or slightly compressible, heterogeneity dominated advective fluid flows. This is largely due to the ability of the streamline method to take large time steps and still produce stable solutions under such conditions. In contrast, the finite difference IMPES method can suffer from stability problems and be severely restricted by time step size. Fully implicit finite difference methods are unconditionally stable but time steps can still be limited due to convergence and/or time truncation errors. Furthermore, they are known to introduce large numerical dispersion if grid block size is large.

The degree to which the pressure depends on the saturation changes can limit the streamline time step size required for converged solutions. Changing well rates and well events can further dictate the need for smaller time steps. In general, for those problems where large and converged time steps can be taken, streamline simulation begins to show a distinct speed advantage over finite difference simulators as models become larger and more heterogeneous. This advantage grows exponentially as the model sizes grow from a million cells to tens of millions to hundreds of million cells.

In the streamline method only one variable, pressure, is solved implicitly using iterative methods, vastly reducing the resource required to solve large problems. After the pressure solution a set of streamlines are generated to represent the flow pattern in the reservoir. Each streamline represents a constant volumetric rate and acts as a one-dimensional space for the saturation solver. Saturations are moved along the streamlines using smaller incremental time steps derived by sub-dividing the duration of the pressure time step. Moving saturations along streamlines implies that the resulting saturation distribution is not affected by grid orientation. The reduction of the three dimensional grid block problem into a set of one dimensional flow problems results in huge efficiency when resolving high resolution geological scale models. High flux zones need more streamlines than low flux zones. The ability to intelligently distribute an optimum number of streamlines to solve a problem adds to the overall efficiency.

At the end of the time step saturations are mapped from streamline space to grid blocks and the process repeated for the next time step.

Streamline simulation allows great flexibility in tuning a solution to fit the type of flow problem to be resolved. For instance, in flow characterization of geological models, gravity can be switched off and only one pressure computation done to generated the streamlines. In waterflood simulation, the front tracking solver or the explicit saturation streamline solver can be employed to reduce numerical dispersion so that breakthrough times are accurately modeled. Finally, for compressible systems or compositional the fluids the fully implicit or adaptive implicit ECLIPSE 300 solvers can be applied on the streamlines.

FrontSim User Guide Introduction to FrontSimFront tracking

17

Front trackingFrontSim is the only commercial simulator to provide a front tracking solver along streamlines. The pressure solution is obtained using a control volume finite difference method which, contrary to standard finite difference methods, gives high accuracy and freedom with respect to grid architecture. The grid system is currently based on hexahedral corner point grid cells.

The saturation equation is a hyperbolic conservation law, describing the velocity of shock fronts. The dispersed displacement process is described by a set of discrete fronts, each defined by a given saturation. The hyperbolic conservation law, through the concept of fractional flow, is used to describe the velocity of each saturation front (shock) as it develops in time.

The solution of the saturation equation is to a large extent independent of grid size and geometry since the grid is not directly used for the solution. The fronts are tracked along streamlines/tubes established from the pressure solution and a typical Buckley-Leverett saturation profile is obtained. Thereby, minimal numerical dispersion takes place.

The solution is fully stable for all time step sizes and the numerical solution method is fast (direct solution). This, in combination with the grid geometry advantages, makes the concept very CPU-efficient compared to traditional finite difference methods, particularly for systems with larger grid blocks.

18 Introduction to FrontSim FrontSim User GuideMajor FrontSim Features

Major FrontSim Features• 2-phase and 3-phase, blackoil and EOS compositional fluid descriptions.

• Simple and IOR Tracers

• Model immiscible and miscible displacements.

• Compressible or incompressible fluids

• Gravity segregation of fluids

• 3-phase relative permeability models and end point scaling.

• Capillary pressure initialization.

• Fully flexible corner-point based grid block geometry. Reads Petrel OPF file format and gOcad format files directly in addition to ECLIPSE formats.

• Cartesian regular and variable spacing Local Grid Refinements (LGRs).

• Full tensor permeabilities - coordinate transformation for standard diagonal permeability input.

• Fault, pinch out modeling and ordinary and region based transmissibility multipliers.

• Multiple PVT, saturation, rock, fluid-in-place and equilibration regions.

• Numerical and analytical carter-tracy, fetkovich and potentiometric aquifers.

• ECLIPSE compatible flux output.

• Hierarchical field-group-well targets, limits and constraints and well management logic.

• Individual well rates and bottom-hole pressure controls.

• Computation of tubing head pressure using vertical flow performance tables.

• Economic limits and workovers.

• Pattern balancing and injection/production allocation information.

• Free-format ECLIPSE compatible input file, keyword structure.

• ECLIPSE compatible output and restart capability.

FrontSim User Guide Programs and FilesPrograms

19

Chapter 3Programs and Files

ProgramsFrontSim is ECLIPSE keyword compatible and the two share the same file format and input data deck structure. Majority of the keywords are common to ECLIPSE except some that are needed to accommodate the streamline computational scheme.

The program is written in ANSI C++ and can be operated on a range of computing platforms. Suitable computers are IBM, SGI, SUN and PCs with Unix, Linux and Windows operating systems as appropriate. For very large models the 64-bit versions of these computers can be used.

FrontSim can be operated in standalone mode using concurrent licensing or as a Petrel module using named user or node-locked licensing. In the latter case, a Petrel core license is required to execute FrontSim.

There are two options to the base FrontSim license. These are compositional and IOR scale up options. Compositional simulation using FrontSim requires an ECLIPSE compositional license. The IOR scale up option is also separately licensed. This option allows the use of recovery type curves, generated by very fine scale ECLIPSE finite difference compositional simulation on sectors; special tracers for gas injection, and oil-water front tracking to efficiently model full field IOR processes.

The recommended pre and post processor for FrontSim is Petrel and/or the ECLIPSE Office suite including Schedule and FloViz. Legacy applications like GridSim are still available for use.

20 Programs and Files FrontSim User GuideFiles

FilesThe user, FrontSim and Pre-Post processors communicate through a set of files as illustrated in Figure 3.1.

Figure 3.1 Programs and files overview

In addition, some files (*_TMP300*) are created for the ECLIPSE 300 link used in 3-phase and compositional runs. These files are temporary, and are normally deleted at the end of the run. However, if for some reason the run terminates abnormally, these files need to be manually deleted. The files involved in a simulation process and their respective purposes are:

FrontSim User Guide Programs and FilesFiles

21

Text files

MYRUN.DATA Main input file for the simulation. May INCLUDE other ASCII files prepared by you or by GridSim.

MYRUN.PRT Except for the simulation log, the contents of this file are controlled by the RPTSCHED keyword. The output to this file is:

• Simulation log - the same information that is printed out to the console

• FIP reports - includes in-place and pressure reports for both field and FIPNUM regions

• Well reports - includes pressure and rate reports for both well flows and connection flows.

• Allocation reports - If ALLOC=2 in RPTSCHED, extended allocation reports are included in the .PRT file

MYRUN.ALLOC This file contains allocation factors and pore volumes (drainage area) for wells and injector-producer pairs. The frequency is controlled by the RPTSCHED keyword.

MYRUN.ALNThis file contains formatted output of allocation/bundle information to for better connectivity to OFM or MS EXCEL. The output is controlled by RPTALLOC.

MYRUN.FSCATThis file uses the Petrel format for storing points data. Point data is created at the grid surface location for every well. This can be used to produce maps in Petrel. For multiple realizations mean and variance maps to represent uncertainty can be created. To generate this file you need to include the GEOFLOFS keyword.

MYRUN.MSG This file, an XML-formatted ASCII file, contains all messages, warnings, errors, and so on, from the simulation run. It is called from keyword MSGFILE.

MYRUN.PFM_SCHEDWhen PFM is activated FrontSim will by default export all PFM rates to the PFM_SCHED file using WCONPROD/ WCONINJE keywords. DATES keywords are also included so this file could be automatically be included into ECLIPSE (or FrontSim).

MYRUN.RSMThis file includes an RSM (Run Summary) report in either EXCEL format, for Cougar for example, XML format or ECLIPSE format. It is set using keyword OPTIONFS.

22 Programs and Files FrontSim User GuideFiles

MYRUN.RFTThis file contains data for one or more wells describing fluid conditions in the wellbore or the connecting grid blocks at selected times in the run. Keyword WRFTPLT is used to generate this file.

For more details on the contents of the PRINT and ALLOCATION files, see "Simulation output" on page 35.

3D visualization files

MYRUN.GRID File containing grid coordinates

MYRUN.INIT File containing geological and other property arrays.

MYRUN.INSPEC Index file for initial file

MYRUN.X000n Restart files generated at requested time steps during the simulation. The files contain block saturations etc. These files are also used to restart a simulation that has either been terminated prematurely or is to be continued from a specific time step.

MYRUN.UNRST Unified restart file, replaces the .X files.

MYRUN.RSSPEC Index file for restart file

MYRUN.SLN000n, MYRUN.SLNSPEC The streamline file format consists of one SLNxxxx file for every report step and one SLNSPEC file for the whole simulation.

Each SLN file holds the geometry and properties of the streamlines, while the SLNSPEC file holds information that is valid for all report steps. The xxxx designates a report step number from 0001 to 9999. Together the files will contain enough information for effective streamline visualization, without any other geometry or property data needed.

The files are UNIX Fortran unformatted binary files, according to the general ECLIPSE standard, to ensure platform independence.

FrontSim User Guide Programs and FilesFiles

23

Line graph files

MYRUN.SMSPEC Names etc. of production data from the simulation.

MYRUN.S000n Values of production data from the simulation.

MYRUN.UNSMRY Unified file for production data, replaces the .S files.

24 Programs and Files FrontSim User GuideKeywords

KeywordsKeywords are implemented in FrontSim using the ECLIPSE syntax style.

ECLIPSE syntaxThis is the syntax of the keywords defined by the ECLIPSE simulator. The keywords are restricted to eight uppercase characters length.

Petrel Keyword ReaderA component that reads simulation input data, using the ECLIPSE syntax. The module is shared between FrontSim and Petrel.

FrontSim User Guide Getting StartedData file sections

25

Chapter 4Getting Started

Data file sectionsThe sections are:

Table 4.1 Data file sections

Notes Section Keyword Description

Required RUNSPEC Title, problem dimensions, switches, phases present, and so on.

Required GRID Specification of geometry of computational grid (location of grid block corners), and of rock properties (porosity, absolute permeability and so on) in each grid block.

Optional EDIT Modifications to calculated pore volumes, grid block center depths and transmissibilities.

Required PROPS Tables of properties of reservoir rock and fluids as functions of fluid pressures, and saturations (density, viscosity, relative permeability, and so on).

Optional REGIONS Splits computational grid into regions for calculation of

PVT properties (Fluid densities and viscosities)

Saturation properties (Relative permeabilities)

Initial conditions (Equilibrium pressures and saturations)

Fluids in place (Fluid in place and inter-region flows)

If this section is omitted, all grid blocks are put in region 1.

26 Getting Started FrontSim User GuideData file sections

The sections must be specified in the order shown above.

It is recommended that the bodies of sections that are not frequently changed be held in separate files, which are included in the data using the INCLUDE keyword.

Note The following section keywords are optional with some applications of GEOFLOFS: PROPS, SOLUTION and SCHEDULE.

Required SOLUTION Specification of initial conditions in reservoir - may be:

Calculated using specified fluid contact depths to give potential equilibrium

Read from a RESTART file set up by an earlier run

Optional SUMMARY Specification of data to be written to the SUMMARY file after each timestep. If no SUMMARY section is included FrontSim will support vectors that were included in the 2005A release of FrontSim and write those after each timestep.

Required SCHEDULE Specifies the operations to be simulated (production and injection controls and constraints), and the times at which output reports are required. Simulator tuning parameters may also be specified in the SCHEDULE section.

Table 4.1 Data file sections

Notes Section Keyword Description

FrontSim User Guide Getting StartedCoordinate and grid system

27

Coordinate and grid systemThe coordinate system for the grid is a right-handed or left-handed system with the Z-axis pointing along the gravity vector (into the screen). The choice between right-handed and left-handed description is up to you, and is implicitly defined by the increasing or decreasing order of the Y coordinates specified.

The grid description is similar to the corner point grid definition used by ECLIPSE.

There are basically two ways to specify a grid as input to FrontSim. Both use a combination of two or more keywords.

COORD and ZCORN general descriptionThe most general way to specify a corner point grid is to give the XYZ coordinates of each one of the eight nodes in each block in the grid. This is done in FrontSim with the keywords COORD and ZCORN (compatible with ECLIPSE). For a detailed description of the use of this format see "Keywords" on page 77.

With COORD, for each of the ((NX+1)*(NY+1)) top/bottom (XY) node pairs, a line is specified in space running through that pair of nodes. All grid nodes are then given by ZCORN depths on these lines.

Note Two neighboring blocks “sharing” nodes might not necessarily be geometrically adjacent to each other since ZCORN depths are given explicitly to all nodes in each block. This gives the option to specify planar faults in the grid.

Note that COORD enables you to specify sloping Z lines, but not to split nodes in the XY plane.

A simpler alternative grid descriptionThis imposes some restrictions on the grid (not allowing faults for example), but the advantage is that the grid description is more compact both on input and internally in the simulator. Hence, this format is recommended for simpler grids.

The keywords involved and possible sequences of use are depicted in Figure 4.1.

28 Getting Started FrontSim User GuideCoordinate and grid system

Figure 4.1 Alternative ways to define the grid

Each path through this diagram describes a way to fully define the grid.

COORDXCOORDY

Define XY nodes.

Define depth for the nodes at the top.

Define depths of the remaining nodes.

COORDZ

DXVDYV

THICKZ

DZV

DEPTHZ

FrontSim User Guide Getting StartedPhase properties

29

Phase propertiesFluids and phases required for a simulation are specified in the RUNSPEC section. The phase options are oil-water, gas-oil, or gas-oil-water. Dead oil, dry gas, water or three immiscible phases are permissible. Live oil (gas dissolved in oil) and oil vaporized in gas (wet gas) can be modeled. Fluid properties can be defined using multiple components and equation-of-state models.

Note Density and viscosity for incompressible, immiscible oil, gas and water can be defined for simple simulations using GEOFLOFS in the RUNSPEC sections.

In the PROPS section the pressure-dependent properties are defined. You must provide a PVT table for each of the phases in the simulation. A PVT table is defined by one of the keywords PVDO, PVDG and PVTW followed by one or more lines of floating point values. Each line in a table must contain a pressure level, the formation volume factor, and the viscosity. The keyword RSCONSTT is used to specify dissolved gas in oil.

Compressibility of oil and gas is defined by supplying multiple lines of PVT values at increasing pressure levels. Water is assumed to have constant viscosity and linear compressibility. The PVTW table always consists of a single line per region, whereas PVDO and PVDG can consist of several lines per region (PVTNUM).

It is also required to specify the phase densities at surface conditions. The densities are defined with the keyword DENSITY, followed by the densities of oil, water, and gas, in that order. All three values must be given. The GRAVITY keyword can also be used.

The PROPS section also allows you to specify the compressibility of the reservoir rock, by using the keyword ROCK. If omitted, the rock matrix is assumed to be incompressible.

For each of the phases in the run, you must provide one or more tables with relative permeabilities. The number of tables per phase must at least be equal to the highest saturation-region number found after the keyword SATNUM, which specifies the relative permeability table for each grid cell. If left unspecified, table 1 is used for all cells.

When running a tracer simulation, the input can contain an adsorption function. The adsorption function is specified by the keywords TADxxx.

The keyword EQUIL is usually used to set the reference pressure and depth, and optionally, the depth of the initial fluid contact(s).

The default initial saturation in a cell is equal to the minimum saturation value found in the relative permeability table for the cell.

Alternatively, initial conditions can be set explicitly with keywords PRESSURE, SWAT, SGAS. Keywords TBLK (initial tracer concentration) and RTEMP (initial temperature) can also be used.

30 Getting Started FrontSim User GuideWell control

Well controlAll wells in a simulation run must be defined with the keyword WELSPECS. This keyword is used to assign type, name, group, position, target producing phase, etc., for the wells. Perforation-related data can be set with the keyword COMPDAT.

The wells can be controlled at three levels; individually, by group, or by field.

When group or field control is applied, the individual rates are set according to the Kh products of each well. Producers can be shut automatically by specifying limits for minimum rate of the producing phase and maximum water cut or gas/oil, water/gas ratio. Also, a limit can be set for each well indicating maximum or minimum bottom hole pressure allowed for injectors/producers respectively. If this limit is exceeded, the rates are automatically reduced to comply with the pressure limit. If group/field rates are used for some wells, then the well limits can still be defined individually, by setting well control keywords before the group/field keywords.

Assume that well P1 is a production well and wells I1 to I4 are injection wells. The producer is placed in the middle of the reservoir and the injectors are placed at each corner. The BHP (bottom hole pressure) is referred to a datum depth of 3500 meters.

The wells are perforated through all (NZ = 50) layers, as described below:

The wellbore diameter is 0.2 m. The Kh product and the skin-factor are given the default values.

DIMENS100 100 50

/

WELSPECSP1 PROD 50 50 3500 LIQ 7* /I1 INJ 1 1 3500 LIQ 7* /I1 INJ 1 100 3500 LIQ 7* /I1 INJ 100 1 3500 LIQ 7* /I1 INJ 100 100 3500 LIQ 7* /

/

COMPDATP1 -1 -1 1 50 2* 1* 0.20 1* 1* 1* Z /I1 -1 -1 1 50 2* 1* 0.20 1* 1* 1* Z /I2 -1 -1 1 50 2* 1* 0.20 1* 1* 1* Z /I3 -1 -1 1 50 2* 1* 0.20 1* 1* 1* Z /I4 -1 -1 1 50 2* 1* 0.20 1* 1* 1* Z /

/

FrontSim User Guide Getting StartedWell control

31

The production well produces 500 Rm3/D, and is shut in if the water cut exceeds 0.9 or the production rate is less that 100 Sm3/D. If BHP drops below 145 bar, the rate is reduced automatically, in accordance with the productivity of the well; the well is under pressure control.

The production data for the injectors are set for the whole group with the keyword below:

The total injection rate is equal to the production rate for 'P1'.

WCONPRODP1 1* RESV 4* 500 145 /

/WECON

P1 100 1* 0.9 //

GCONINJEINJ WATER VREP 3* 1 /

/

32 Getting Started FrontSim User GuideOptimizing Performance

Optimizing PerformanceThe time required to execute a simulation run is a function of the number of timesteps or pressure solutions and the time it takes to solve each individual timestep.

The number of pressure solutions required depends on the maximum timestep size that can be taken and still achieve converged solutions of pressure and saturations. The size of converged timesteps depends on the reservoir processes being modeled. For example, an incompressible single phase simulation with constant injection and production rates requires only one pressure calculation. At the other extreme, the timestep size for a compressible multiphase flow problem with gravity segregation, and changing production and injection rates, will require several computations of the pressure field.

The work done by FrontSim to solve a timestep can essentially be divided into two parts:

• solving the pressure field and constructing streamlines

• solving the saturation equations along the streamlines.

FrontSim solves pressure fully implicitly using an iterative technique. The default convergence criteria satisfy most problems. In complex cases the convergence criteria may need to be tightened to achieve required accuracy. Alternatively, the timestep may need to be reduced. Any problem diagnosis should begin by examining the convergence of the pressure solutions.

The time required to solve the saturation distribution is a function of the number of streamlines. The number of streamlines must meet the requirements for accurate discretization of the flux field. As with any discretization scheme there is an optimum - very coarse discretization (fewer streamlines) will introduce errors, while finer discretization will introduce unnecessary CPU work. A related minor factor is the number of cells within a streamline or the discretization of the streamline space itself.

There are as yet no robust mathematical criteria to predict convergence for real-world streamline simulation problems. The practical method is to make trial simulations with different timestep sizes and observe the convergence of output variables like pressure, water cut, etc. Several runs with different MAXSTEP sizes can easily give an estimate of the maximum timestep that can be taken without compromising the accuracy of the final results.

An often-overlooked factor that could affect the performance of the simulation is the modeling of well performance and the need to honor constraints and limits while achieving converged reservoir and well solutions. At initial stages of a history match or for sensitivity studies of reservoir parameters, well connection factors may be adjusted to ensure wells do not switch to bottom hole pressure control.

TimestepsThe speed advantage of FrontSim comes mostly from its ability to take long timesteps. To get this benefit, you must set up your schedule data for timesteps such as 3, 6 or 12 months, which are common choices. Please note that you need to check the maximum timestep limit for converged solutions as described above.

FrontSim sets default maximum timesteps for different types of runs: incompressible two phase is set at 1825 days, compressible two phase at 730 days, three phase blackoil at 90 days, and compositional at 30 days. If your run is capable of taking large timesteps, with converged results, then override these defaults using MAXSTEP.

FrontSim User Guide Getting StartedOptimizing Performance

33

The automatic timestepping criteria, keyword TSCRITFS, can help in automatically controlling timestep size for complex problems. The easiest parameter to try is the maximum allowable pressure change per timestep. The other parameters control throughput and mostly can be left at their default values. An option is provided to cut the timestep if the pressure solver fails to converge. By default, FrontSim proceeds to the next step if the number of newton iterations is exhausted.

Tuning the Pressure SolverYou may consider tuning the pressure solver with keyword TUNEFSPR. However, this is not usually necessary since the default values are in general acceptable.

• You can change the limit of material balance error with item 2: streamline methods do not intrinsically force a material balance at the end of the timestep. There are several factors that can affect the material balance error - inconsistencies in input data, and inappropriate tuning. Increase this number only if you want to debug problem datasets.

• Decreasing the convergence error limits with items 3 and 4 is not recommended. Tightening the convergence criteria for difficult problems may help reduce the material balance error.

• Increasing the number of Newton iterations with item 5 can help with cases where the solution is difficult to converge. Such runs will generally perform slowly, and if possible the cause of the convergence problem should be identified and resolved. Nevertheless, it may be preferable to take an additional Newton iteration, if the alternative is to reduce the timestep length.

Choosing a Saturation SolverThe saturation solver is selected and tuned with keyword TUNEFS1D.

Front Tracking The default solver for two-phase oil-water problems is Front Tracking. The number of fronts tracked along a streamline depends on the number of rows in the relative permeability table input. Fewer rows or saturation points will result in fewer fronts being tracked and quicker simulations, but less resolution of the flood front.

Explicit Gudonov Solver This solver is the default for 2- and 3-phase blackoil problems. It is much faster than the ECLIPSE 300 solver described below. However, this solver assumes that the pressure along the streamline does not change with saturation changes.

ECLIPSE 300 Solver There are three different methods to choose from:

• fully implicit

• adaptive implicit

• impes (implicit pressure explicit saturation).

34 Getting Started FrontSim User GuideOptimizing Performance

For complex blackoil problems these solvers are recommended; for compositional simulation, the fully implicit solver is used by default.

Tuning the Saturation SolutionThe saturation solution is tuned with keyword TUNEFSSA.

• The frequency of Segregation Iterations within each timestep is controlled with item 1. If gravity segregation is not a significant process in the reservoir you can speed up the run: turn off the computation by setting this parameter to 0.

• The Streamline Density multiplier is, after timestep length, the most significant parameter affecting speed. It also impacts the amount of memory required to solve a problem. It is surprising that very large and heterogeneous models may actually require significantly fewer streamlines. You can switch on automatic streamline density computation by setting this value to -1. There is a slight overhead in the optimization. The recommended process is to enter the maximum or modal value for the streamline density multiplier, computed from an optimized run, as a constant in subsequent runs.

FrontSim User Guide Getting StartedSimulation output

35

Simulation outputIn "Programs and Files" on page 19 there is a short description of the output files that FrontSim generates during a simulation run. Two of these files − the PRT and ALLOC files - are described in more detail in the following pages:

Simulation log and FIP/Well reportsThe contents of the PRINT file are divided into three categories:

• The simulation log

• FIP and WELL reports

• ALLOC reports

The simulation log is also directed to the console window.

Keyword reader/parserAt the start of the simulation, after the license check, FrontSim reports which keywords are being read from the input file:

36 Getting Started FrontSim User GuideSimulation output

While FrontSim reads all the input keywords it checks the data to see if there are any errors in the input, or if there are keywords that are not recognized.

If there are any keywords in the input data that are valid keywords (accepted by ECLIPSE 100 and/or ECLIPSE 300), but not recognized by FrontSim, they are ignored and the simulation continues:

FrontSim Version: 2006.1 User Name : mgaupaas OS Name : Microsoft Windows 2000 (Build 5.1.2600 Service Pack 2) Host Name : PETREL-MGAUPAAS Exe Path : 2006.1_w07\frontsim.exe Current Date : Feb 13 2006 Build Date : Feb 11 2006

Reading Input file: C:/Home/Data/HIRES.DATA Section RUNSPEC -> FRONTSIM -> TITLE -> DIMENS -> METRIC -> OIL -> WATER -> START......... Section SCHEDULE Box 1,21,1,21,1,1 -> TUNEFSSA -> RPTRST -> WELSPECS -> WCONPROD -> WCONINJ -> WECON -> TSTEP -> TSTEP -> TSTEP -> TSTEP -> TSTEP Endbox 1,21,1,21,1,1

-> GRUPTREE-> GRUPTREE not supported

-> WCONHIST....


37

If the parser detects any errors in the input file, such as missing or incomplete specification of grid properties, it terminates immediately. This could happen while reading the data or while validating:

Simulation CharacteristicsWhen reading and parsing of the input data is finished the main characteristics for the simulation, including the total number of active/inactive cells, are reported.

-> WCONPROD @--Error at time 1 January 1992 step 0: @ WCONPROD: Control not valid for P1

Numerical Method: STANDARD Dimension : 2D Segregation : OFF Compressibility : NO Tensor : DIAGONAL Equation Solver : ONE LEVEL METHOD Local Grids : NO Boundary Cond. : NO Simulation start: 01 January 2000

GridName Id Level Cells Active GLOBAL 0 0 19894410 19884410 Total: 19894410 19884410


Timestep reportsAt every timestep, FrontSim reports average pressure, fluids in place, net cumulative flows and MBE (Mass Balance Errors) for each phase:

MessagesThere are currently four levels of severity for messages to the simulation log. These are, in order:

1 = Message (Not an error, purely informative)

2 = Warning (Possibly a data error)

3 = Error (Definitely a data error)

4 = Bug (Suspected programming error).

The messages are reported with a header, which includes time and step information:

------------------------------------------------------------------------------ Report 1 Time 0.00 --> 365.00 (31 Dec 2000) StopTime: 2920.00 // Time/date info for current report step @ Starting up producer(s) P1, P2 // Starting up producers @--Message at time 1 January 2000 step 1: @ Starting up injector(s) I1 // Starting up injectors Step 1 Time 0.00 --> 365.00 Reason:Report // Time/date info for current stepPressure : 106 4.1e-06 1 1.1e-02 // 1st Newton it. −#lin iter −inner norm - #ulin iter - outer norm Pressure : 23 2.1e-06 2 1.5e-0502 // 2nd Newton it. −#lin iter −inner norm - #ulin iter - outer norm Saving : ecl_sample11.b0001 // Saving streamlines to binary file Saturation : Generated 916 starting points. // Number of streamlines

Added 36 Saving : ECL_SAMPLE05.SLN0001 // Saving streamlines

CPU Pressure : Asm 0.0 Sol 0.0 Vt 0.0 Tot 0.0 CPU Saturation : Tot 0.0 Mem heap(Mb) : 59.1 // Peak memory usageMem usage pr active cell (Kb) : 1.2 CPU Cumulative : Asm 0.0 Sol 0.0 Vt 0.0 Sat 0.0 Tot 0.0 PV 4.999990e+005 at ref. pressure PV 4.999990e+005 RC 3.65% PAV 2.5033e+002 WIP 1.825000e+004 CWF -1.825000e+004 WIIP 0.000000e+000 MW -0.00% OIP 3.705762e+005 COF 1.403844e+004 OIIP 3.846146e+005 MO 0.00% GIP 0.000000e+000 CGF 8.423066e+005 GIIP 0.000000e+000 MG 0.00% Saving: ecl_sample11.x0001 // Saving restart file ------------------------------------------------------------------------------

Report 1 Time 0.00 --> 365.00 (31 Dec 2000) StopTime: 2920.00 @ Starting up producer(s) P1, P2 @--Message at time 1 January 2000 step 1: @ Starting up injector(s) I1 Step 1 Time 0.00 --> 365.00 Reason: Report


39

Pressure solverIf the simulation is incompressible the pressure solver displays two numbers:

1 the number of iterations the linear solver has used

2 the value of the resulting computed error norm.

The latter should be smaller than a given threshold. If not, the computation is stopped after a preset number of times, at which point the solution may not have converged.

In the case of a compressible run a couple more columns are added. These give the number of the current outer (newton) iteration used to solve the now nonlinear pressure equation, and the corresponding error norm. The outer iteration is repeated, giving more lines of output, until the convergence criteria are satisfied.

Saturation solverThe saturation solver reports the number of streamlines that are generated (‘starting points’). There may be cells that are not intersected by any streamline. If requested by the user, FrontSim generates new streamlines through these cells. In the above example 36 new streamlines were added.

Additional information when using the ECLIPSE 300 solvers

The lines beginning "Pressure change" indicate the maximum and root mean square pressure differences between the pressures calculated for each cell as a result of the pressure solution, and the pressure calculated from the results from the streamline saturation solver. The second line indicates the change in pressure between

• the value calculated from the results from the streamline saturation solver

• the value calculated from the results from the gravity line saturation solution.

CPU usageFollowing the saturation solver report there is a CPU time usage report. The total pressure solver CPU time usage for the current step is split up into time used to assemble the pressure equation, time used to calculate the field of Darcy velocities, and time used to solve the pressure equation. A separate line gives the time used by the saturation solver. A final line gives the accumulated time usage up to and including this step.

Memory UsageFrontSim reports the peak memory usage for the process and also per active cell, in kB.

Volumes and MBE calculationsThe last set of numbers describes produced and resident volumes. Their individual meanings are as follows:

Table 4.2 Production parameters (fluids in place and volumetric flows)

Parameter DescriptionWIIP Water Initially In Place

OIIP Oil Initially In Place

GIIP Gas Initially In Place

CWF Net Water flows (Production-Injection)


Here PVi and Bvi are initial reservoir pore volume and initial volumetric formation factors. For alternative ways to calculate MBE, see the OPTIONFS keyword.

Well and FIP ReportsTo be able to output reports for wells and FIPNUM regions in the PRINT file, the RPTSCHED (or RPTPRINT) keyword must be included in the SCHEDULE section.

An example of a complete report looks like this:

Parameter DescriptionCOF Net Oil flows (Production-Injection)

CGF Net Gas flows (Production-Injection)

WIP Water In Place

OIP Oil In Place

GIP Gas In Place

Table 4.3 Material Balance Error reports (MBE)

Parameter DescriptionMW (WIIP-CWF-WIP)/(PVi/Bwi)

MO (OIIP-COF-OIP)/(PVi/Boi)

MG (GIIP-CGF-GIP)/(PVi/Bgi)

Table 4.4 Other

Parameter Description NotesRC Recovery RC = COF / OIIP (%)

PV at ref. pressure Pore volume at reference pressure

PV Pore volume at reservoir conditions

PAV Field Average Pressure

Table 4.2 Production parameters (fluids in place and volumetric flows)

1---------------------------------------------------------------------------------------3FIP FIP Regions 31.0000 Days report step 1, 1 Feb 1988----------------------------------------------------------------------------------------

|-------------------------------------------------------------------------------------|| Region | Pressure | WIP | OIP | GIP | WIIP | OIIP | GIIP | |-------------------------------------------------------------------------------------|| 0| 3.951e+02| 5.672e+07| 3.061e+07| 0.000e+00| 5.665e+07| 3.069e+07| 0.000e+00|| 1| 3.955e+02| 2.059e+07| 1.590e+07| 0.000e+00| 2.055e+07| 1.594e+07| 0.000e+00|| 2| 3.950e+02| 1.873e+07| 9.117e+06| 0.000e+00| 1.871e+07| 9.136e+06| 0.000e+00|| 3| 3.938e+02| 1.740e+07| 5.598e+06| 0.000e+00| 1.739e+07| 5.616e+06| 0.000e+00||-------------------------------------------------------------------------------------|


41

1---------------------------------------------------------------------------------------4WELLS Status of wells and groups 365.0000 Days report step 1, 31 Dec 2000 ----------------------------------------------------------------------------------------PRODUCTION REPORT |---------------------------------------------------------------------------------------|| Well or Group | I | J | K | Grid | WellCnt | THP/Blck | BHP | ResRate | OilRate | WaterRate| GasRate | KhProd | Windex | Pindex || | | | | | | BAR | BAR | RM3/DAY | SM3/DAY | SM3/DAY | SM3/DAY | MD-METRE | CPM3/D/B | M3/D/BAR ||---------------------------------------------------------------------------------------||---------------------------------------------------------------------------------------|| FIELD| | | | | |8.000e+001|8.000e+001|0.000e+000|0.000e+000| | | ||---------------------------------------------------------------------------------------||---------------------------------------------------------------------------------------|| A| GROUP| | | | |8.000e+001|8.000e+001|0.000e+000|0.000e+000| | | ||---------------------------------------------------------------------------------------|| P1| 14| 32| | 0| RESV |0.000e+000|2.513e+00|4.000e+001|4.000e+001|0.000e+000|0.000e+000|5.000e+002|8.456e+000|8.456e+000| | 14| 32| 1| 0| |2.561e+002|2.513e+002|4.000e+001|4.000e+001|0.000e+000|0.000e+000|5.000e+002|8.456e+000|8.456e+000|| P2| 14| 8| | 0| RESV|0.000e+000|2.513e+002|4.000e+001|4.000e+001|0.000e+000|0.000e+000|5.000e+002|8.456e+000|8.456e+000| | | 14| 8| 1| 0| |2.561e+002|2.513e+002|4.000e+001|4.000e+001|0.000e+000|0.000e+000|5.000e+002|8.456e+000|8.456e+000|

|---------------------------------------------------------------------------------------|INJECTION REPORT |---------------------------------------------------------------------------------------|| Well or Group | I | J | K | Grid| WellCnt|THP/Blck | BHP | ResRate | OilRate | WaterRate| GasRate | KhProd | Windex | Pindex || | | | | | | BAR | BAR | RM3/DAY | SM3/DAY | SM3/DAY | SM3/DAY | MD-METRE | CPM3/D/B | M3/D/BAR ||---------------------------------------------------------------------------------------||---------------------------------------------------------------------------------------|| FIELD| | | | | |8.000e+001|0.000e+000|8.000e+001|0.000e+000| | | ||---------------------------------------------------------------------------------------||---------------------------------------------------------------------------------------|| A| GROUP| | | | |8.000e+001|0.000e+000|8.000e+001|0.000e+000| | | ||---------------------------------------------------------------------------------------|| I1| 1| 20| | 0| VREP |0.000e+000|3.231e+002|8.000e+001|0.000e+000|8.000e+001|0.000e+000|5.000e+002|8.456e+000|8.456e+000| | | 1| 20| 1| 0| |3.137e+002|3.231e+002|8.000e+001|0.000e+000|8.000e+001|0.000e+000|5.000e+002|8.456e+000|8.456e+000||---------------------------------------------------------------------------------------||---------------------------------------------------------------------------------------|


The FIP report includes pressure and fluid-in-place reports for each FIP region (0 indicates FIELD properties).

The well (and completion) report comprises the following properties (from left to right):

• Well name

• Group name

• Pressure at the drainage radius at datum depth

• Bottom hole pressure at datum depth

• Sum of phase rates at reservoir conditions

• Oil rate at surface conditions

• Water rate at surface conditions

• Gas rate at surface conditions

• Permeability times thickness.

• Well index or connection factor.

• Productivity index.

Allocation factor reportsThe ALLOC file is an additional print file from the simulation (see RPTSCHED). This file contains allocation factors and pore volumes (drainage area) for wells and for injector-producer pairs.

Well names Each well has one line of output for the total of the well and one for each bundle associated with this well. A bundle is a set of streamlines that connects an injector-producer pair.

CUMULATIVE PRODUCTION/INJECTION TOTALS |---------------------------------------------------------------------------------------|| Well Name | I | J | K |Grid|Well|Cntrl|Oil|Water|Gas|Res.Vol.|Oil|Water|Gas| Res.Vol.|| | | | | | Type | Mode |Production|Production|Production|Production|Injection |Injection |Injection | Injection || | | | | | | SM3 | SM3 | SM3 | RM3 | SM3 | SM3 | SM3 | RM3 ||---------------------------------------------------------------------------------------||---------------------------------------------------------------------------------------||FIELD| | | |2.920e+004 |0.000e+000|0.000e+000 |2.920e+004 |0.000e+000 |2.920e+004 |0.000e+000 |2.920e+004 ||---------------------------------------------------------------------------------------||---------------------------------------------------------------------------------------||---------------------------------------------------------------------------------------|| A| GROUP| | |2.920e+004 |0.000e+000 |0.000e+000 |2.920e+004 |0.000e+000 |2.920e+004 |0.000e+000 |2.920e+004 ||---------------------------------------------------------------------------------------|| P1| 14| 32| | 0|PROD|RESV |1.460e+004 |0.000e+000 |0.000e+000 |1.460e+004 |0.000e+000 |0.000e+000 |0.000e+000 |0.000e+000 || P2| 14| 8| | 0|PROD|RESV |1.460e+004 |0.000e+000 |0.000e+000 |1.460e+004 |0.000e+000 |0.000e+000 |0.000e+000 |0.000e+000 || I1| 1| 20| | 0|INJ |VREP |0.000e+000 |0.000e+000 |0.000e+000 |0.000e+000 |0.000e+000 |2.920e+004 |0.000e+000|2.920e+004 |


43

Rate for the well or for the bundles.This is the total rate at reservoir conditions.

Surface phase rates for the well or for the bundles. These are only included in the extended reports generated by setting the ALLOC mnemonic in keyword RPTSCHED to 2 or 3.

Allocation factorBundle rate divided by well rate.

Pore VolumeThe pore volume represented by the bundle or well.

I-edge Injection not represented by an injector - which is the boundary conditions (PSIDE etc.).

P-edge Production not represented by a producer - which is the boundary conditions (PSIDE etc.).

The total pore volume not visited by any cell and the total pore volume for the reservoir are also reported.

The following is an example of a simple allocation report generated by setting the ALLOC mnemonic in keyword RPTSCHED to 3.


1---------------------------------------------------------------------------------- 5 ALLOC Allocation/bundle report 365.0000 Days report step 1, 31 Dec 2000------------------------------------------------------------------------------------|-----------------------------------------------------------------------------------|| Streamline | | | | | || Bundle | | Surface Rate | Surface Volumes | | ||------------------| Flow |-----------------------------------|Total Reservoir |Pore ||Start |End | Direct | Oil | Water | Gas | Oil | Water | Gas | Rate | Volume ||----------------------------------------------------------------------------------|| | SM3/D | Fraction | SM3/D |Fraction |SM3/D |Fraction | SM3 | SM3 | SM3 | RM3/D | Fraction | RM3 ||-----------------------------------------------------------------------------------||P1 | | 4.00e+001 | | 0.00e+000 | | 0.00e+000 | | 9.12e+004 | 1.47e+004 | 0.00e+000 | 4.00e+001 | 1.00e+000 | 1.06e+005 || P1 I1 | Outflow | 4.00e+001 | 1.00e+000 | 0.00e+000 | 0.00e+000 | 0.00e+000 | 0.00e+000 | 9.12e+004 | 1.47e+004 | 0.00e+000 | 4.00e+001 | 1.00e+000 | 1.06e+005 ||----------------------------------------------------------------------------------|| P2 | | 4.00e+001 | | 0.00e+000 | | 0.00e+000 | | 9.02e+004 | 1.45e+004 | 0.00e+000 | 4.00e+001 | 9.96e-001 | 1.05e+005 || P2 I1 | Outflow | 4.00e+001| 1.00e+000 | 0.00e+000 | 0.00e+000 | 0.00e+000 | 0.00e+000 | 9.02e+004 | 1.45e+004 | 0.00e+000 | 4.00e+001 | 1.00e+000 | 1.05e+005 ||-----------------------------------------------------------------------------------|| I1 | | 0.00e+000 | | 8.00e+001 | | 0.00e+000 | | 1.81e+005 | 2.92e+004 | 0.00e+000 | 8.00e+001 | 1.00e+000 | 2.11e+005 || I1 P2 | Inflow | 0.00e+000 | 0.00e+000 | 3.98e+001 | 4.98e-001 | 0.00e+000 | 0.00e+000 | 9.02e+004 | 1.45e+004 | 0.00e+000 | 3.98e+001 | 4.98e-001 | 1.05e+005 || I1 P1 | Inflow | 0.00e+000 | 0.00e+000 | 4.02e+001 | 5.02e-001 | 0.00e+000 | 0.00e+000 | 9.12e+004 | 1.47e+004 | 0.00e+000 | 4.02e+001 | 5.02e-001 | 1.06e+005 ||-----------------------------------------------------------------------------------|| I-edge | | 0.00e+000 | | 0.00e+000 | | 0.00e+000 | | 0.00e+000 | 0.00e+000 | 0.00e+000 | 0.00e+000 | 0.00e+000 | 0.00e+000 ||-----------------------------------------------------------------------------------|| P-edge | | 0.00e+000 | | 0.00e+000 | | 0.00e+000 | | 0.00e+000 | 0.00e+000 | 0.00e+000 | 0.00e+000 | 0.00e+000 | 0.00e+000 ||-----------------------------------------------------------------------------------|

FrontSim User Guide Getting StartedSample case data file

45

Sample case data file

-- sample fileRUNSPECTITLEFrontsim 2D sample caseDIMENS 20 20 1 /FIELDOILWATERSTART1 JAN 1990 /TABDIMS1 1 /WELLDIMS15 1 1 15 /GRIDGRIDFILE2 /INIT

DXV20*25 /DYV20*25 /DEPTHZ441*2500/DZV 40 /

PORO400*0.25 /

PERMX400*100 /PERMY400*100 /PERMZ400*100 /PROPSPVDO1800 1.05 1.24 /PVTW1800 1 0 0.5 /

46 Getting Started FrontSim User GuideSample case data file

RSCONSTT0.1 0 /DENSITY50 50 1 /SWOF0.25 0 1 0 0.3 0.06 0.737 0 0.35 0.12 0.558 0 0.45 0.24 0.337 0 0.5 0.3 0.263 0 0.55 0.36 0.189 0 0.6 0.435 0.116 0 0.7 0.6 0 0 1 1 0 0 /

REGIONSSOLUTIONEQUIL2500 1800 /SWAT400*0.25 /SUMMARYSCHEDULETUNEFSSA1* 1* 0 0 1* 1* 1* 1* /

WELSPECSP1 UNS 0 0 1* LIQ 7* 5.1 219.3 /P2 UNS 0 0 1* LIQ 7* 137.7 382.6 /P3 UNS 0 0 1* LIQ 7* 76.5 66.3 /P4 UNS 0 0 1* LIQ 7* 239.7 443.8 /P5 UNS 0 0 1* LIQ 7* 443.8 56.1 /P6 UNS 0 0 1* LIQ 7* 270.4 147.9 /P7 UNS 0 0 1* LIQ 7* 372.4 423.4 /P8 UNS 0 0 1* LIQ 7* 56.1 372.4 /P9 UNS 0 0 1* LIQ 7* 443.8 158.1 /P10 UNS 0 0 1* LIQ 7* 311.2 229.5 /I1 UNS 0 0 1* LIQ 7* 494.8 494.8 /I2 UNS 0 0 1* LIQ 7* 5.1 5.1 /I3 UNS 0 0 1* LIQ 7* 372.4 270.4 /I4 UNS 0 0 1* LIQ 7* 127.5 494.8 /I5 UNS 0 0 1* LIQ 7* 66.3 250 //RPTRST3 4* 1 /

FrontSim User Guide Getting StartedSample case data file

47

WCONPRODP1 1* RESV 4* 5 1* /P2 1* RESV 4* 5 1* /P3 1* RESV 4* 5 1* /P4 1* RESV 4* 5 1* /P5 1* RESV 4* 5 1* /P6 1* RESV 4* 5 1* /P7 1* RESV 4* 5 1* /P8 1* RESV 4* 5 1* /P9 1* RESV 4* 5 1* /P10 1* RESV 4* 5 1* //

WCONINJEI1 WATER 1* RESV 1* 10 /I2 WATER 1* RESV 1* 10 /I3 WATER 1* RESV 1* 10 /I4 WATER 1* RESV 1* 10 /I5 WATER 1* RESV 1* 10 //

TSTEP2*912.5 /

WCONPRODP1 SHUT RESV 4* 0 1* /P2 SHUT RESV 4* 0 1* /P3 SHUT RESV 4* 0 1* /P7 SHUT RESV 4* 0 1* /P8 SHUT RESV 4* 0 1* /P9 SHUT RESV 4* 0 1* /P10 SHUT RESV 4* 0 1* //

WCONINJEI1 WATER 1* RESV 1* 3 /I2 WATER 1* RESV 1* 3 /I3 WATER 1* RESV 1* 3 /I4 WATER 1* RESV 1* 3 /I5 WATER 1* RESV 1* 3 //

TSTEP2*912.5 /

48 Getting Started FrontSim User GuideSample case data file

FrontSim User Guide Data File OverviewIntroduction

49

Chapter 5Data File Overview

IntroductionThis chapter contains a list of the keywords that FrontSim uses, arranged by the sections in which they appear in the data files. See "Getting Started" on page 25 for more details on the individual sections.

The sections are presented as a series of tables, each containing details of the keywords for a particular section.

• "RUNSPEC section" on page 50

• "GRID section" on page 51

• "EDIT section" on page 54

• "PROPS section" on page 55

• "REGIONS section" on page 58

• "SOLUTION section" on page 59

• "SUMMARY section" on page 60

• "SCHEDULE section" on page 73.

50 Data File Overview FrontSim User GuideRUNSPEC section

RUNSPEC sectionThe keywords are:

Table 5.1 RUNSPEC keywords

Keyword DescriptionCOMPS Requests compositional mode

DIMENS Specifies the dimensions of the grid

DUALPORO Activates dual porosity option

END Denotes the logical end of an input file

ENDINC Denotes the logical of end of an INCLUDE file

ENDSCALE Use saturation table end-point scaling

EOS Specifies which equation of state equation is to be used

FDM9PNT Specifies the finite difference method

FIELD Specifies that field units are to be used

FRONTSIM Accept only FrontSim keywords

GAS Indicates that the simulation run includes gas

GEOFLOFS Setup Simple Simulations for Flow Analysis on Geologic Models

INCLUDE Includes the contents of another named file

METRIC Specifies that metric units are to be used

MSGFILE Generate an XML-formatted message file

NOGRAV Sets gravity to zero

NOSIM Turn off simulation

OPTIONFS Activates special program options

OIL Indicates that the simulation run contains oil

PERFORM FrontSim performance tuning

START Specifies a start date

TABDIMS Defines the table dimensions, for saturation and PVT tables

THREADFS Activate multicore parallel option

TITLE Specifies the run title

UNIFIN Indicates that input files are unified

UNIFOUT Indicates that the information written to the RESTART and SUMMARY files is to be unified

WATER Indicates that the simulation run contains water

WELLDIMS Describes the dimensions of the well data used in the run.

FrontSim User Guide Data File OverviewGRID section

51

GRID sectionThe keywords are:

Table 5.2 GRID keywords

Keyword DescriptionACTNUM Identifies the active grid blocks in the current boxADD Adds a constant to the specified array in the current box

AQUCON Specifies connection data for numerical aquifers

AQUNUM Assigns a numerical aquifer to a block

BOX Redefines the current input box

CARFIN Specifies a cartesian local grid refinement

COORD Specifies coordinate lines

COORDXYZ Specifies the X, Y, Z coordinates of a grid

COPY Copies data from one array to another

DEPTHZ Specifies depth for all the nodes in the top layer

DPGRID Make matrix cell properties for fracture cell

DXV/DYV Specifies the size of the grid cells in the X or Y direction

DZV Specifies the size of the grid cells in the Z direction

DUMPFLUX Output a flux file


ENDBOX Resets the current input box to encompass the entire grid

ENDFIN Terminates the data for a local grid refinement

ENDINC Denotes the logical of end of an include file

EQUALS Sets an array to a constant in the current box

FAULTS Defines a set of faults

FLUXNUM Defines flux regions, for editing GRID section data.

FLUXTYPE Specify type of flux boundary condition

GADJUST Transforms the permeability tensor from local coordinates to the global coordinate system

GOCADGRI Recognize stratigraphic grid

GRIDFILE Controls the output of the grid geometry file

HXFIN Local grid size ratios in x-direction

HYFIN Local grid size ratios in y-direction

HZFIN Local grid size ratios in z-direction


INIT Requests the output of an INIT file

JFUNC Activates the Leverett-J option

MAPAXES Input of pre-processor map origin

52 Data File Overview FrontSim User GuideGRID section

MAPUNITS Specifies units used for MAPAXES data

MINPV Sets the minimum pore volume a cell must have to be active

MULTFLT Modifies the transmissibility across a named fault

MULTIPLY Multiplies an array by a constant in the current box

MULTNUM Defines regions for applying inter-region transmissibility multipliers

MULTPV Pore volume multipliers

MULTREGT Multiplies the transmissibility between flux or MULTNUM regions

MULTX Transmissibility multipliers in X-direction

MULTX- Transmissibility multipliers in the negative X-direction

MULTY Transmissibility multipliers in Y-direction

MULTY- Transmissibility multipliers in the negative Y-direction

MULTZ Transmissibility multipliers in Z-direction

MULTZ- Transmissibility multipliers in the negative Z-direction

NODPPM No dual porosity multiplier

NTG Defines the net to gross thickness ratios

NTRNSAVE Saves the transmissibilities in memory

NXFIN Sets the number of local cells in each global cell of a local grid refinement in X direction

NYFIN Sets the number of local cells in each global cell of a local grid refinement in Y direction

NZFIN Sets the number of local cells in each global cell of a local grid refinement in Z direction

PERMX Specifies the permeability in X-direction

PERMY Specifies the permeability in Y-direction

PERMZ Specifies the permeability in Z-direction

PERMXY, PERMYZ, PERMZX, PERMXX, PERMYY, PERMZZ

Specifies off-diagonal tensor permeability coefficients

PETGRID Recognize grid and properties in Open Petrel Format

PINCH Generates connections across pinched-out layers

PINCHNUM Identifies pinchout regions

PINCHREG Generates connections across pinched-out layers within regions

PINCHXY Generates horizontal pinchout connections

PORO Specifies the grid block porosity values

REFINE Initiates data input for a named local grid

SIGMA Dual Porosity matrix-fracture coupling


Keyword Description

FrontSim User Guide Data File OverviewGRID section

53

SIGMAV Dual Porosity matrix-fracture coupling

THICKZ Sets the layer thickness in the Z direction

ZCORN Specifies the depths of the grid block corners.


Keyword Description

54 Data File Overview FrontSim User GuideEDIT section

EDIT sectionThe keywords are:

Table 5.3 EDIT keywords

Keyword DescriptionADD Adds a constant to the specified array in the current box



EDITNNC Changes a non-neighbor connection







MULTFLT Modifies the transmissibility across a named fault

MULTIPLY Multiplies an array by a constant in the current box

MULTPV Pore volume multipliers

PORV Specifies the grid block pore volumes


TRANX X-direction transmissibility values.

TRANY Y-direction transmissibility values.

TRANZ Z-direction transmissibility values.

FrontSim User Guide Data File OverviewPROPS section

55

PROPS sectionThe keywords are:

Table 5.4 PROPS keywords

Keyword DescriptionACF Defines the acentric factor

ADD Adds a constant to the specified array in the current box

AQUTAB Influence function tables for Carter-Tracy aquifers

BIC Defines the binary interaction coefficients


CNAMES Defines the component names for reporting purposes


DENSITY Defines the fluid densities at surface conditions





ENKRVD Sets relative permeability scaling as a function of depth

ENPTVD Saturation end point versus depth tables

EOS Specifies which equation of state equation is to be used

EPSDEBUG EPS debug


GRAVITY Fluid gravities at surface conditions

HEATCAP Defines the heat capacity for rock and fluid


KRG Scaled end point gas relative permeabilities

KRGR Scaled end point gas relative permeabilities

KRO Scaled end point oil relative permeabilities

KRORG Scaled end point oil relative permeabilities

KRORW Scaled end point oil relative permeabilities

KRW Scaled end point water relative permeabilities

KRWR Scaled end point water relative permeabilities

MW Defines the molecular weights

OMEGAA Overrides the default values

OMEGAB Overrides the default values

PARACHOR Defines component parachors

PCRIT Defines critical pressures

PCW Sets maximum Oil Water capillary pressure

Ωa

Ωb

56 Data File Overview FrontSim User GuidePROPS section

PPCWMAX Sets maximum Oil Water capillary pressure that can result from Leverett JFUNC calculation

PRCORR Requests the use of the modified Peng-Robinson equation of state

PVDG Defines the PVT properties of dry gas

PVDO Defines the PVT properties of dead oil

PVTG Defines the PVT properties of wet gas

PVTO Defines the PVT properties of live oil

PVTW Defines the water PVT functions


ROCK Defines rock compressibility

RSCONSTT Sets a constant for each dead oil PVT table

RTEMP Specifies the initial reservoir temperature

RVCONSTT Sets a constant for each dry gas PVT table

SCALECRS Controls the end point scaling method

SGCR Scaled critical gas saturations

SGL Scaled connate gas saturations

SGU Scaled saturation table maximum gas saturations

SGFN Defines the gas saturation functions

SGOF Specifies the gas/oil saturation functions versus gas saturation

SOF2 Specifies the oil saturation functions (2 phase)

SOF3 Specifies the oil saturation functions (3 phase)

SOGCR Scaled critical oil-in-gas saturations

SOWCR Scaled critical oil-in-water saturations

SSHIFT Defines the equation of state shift parameters

STCOND Specifies the standard conditions

STONE1 Requests the Stone three-phase oil relative permeability model

STONE2 Requests the Stone three-phase oil relative permeability model

SWATINIT Sets the capillary pressure scaling based on the initial water saturation

SWCR Scaled critical water saturations

SWFN Defines the water saturation functions

SWL Scaled connate water saturations

SWOF Specifies the water/oil saturation functions versus water saturationSWU Scaled saturation table maximum water saturationsTAD Specifies the adsorption function for tracersTADE Specifies the adsorption for the EOR tracerTCRIT Specifies the critical temperaturesTREFFIC Defines the table of IOR mobilization curve data


Keyword Description

Rs

Rs

FrontSim User Guide Data File OverviewPROPS section

57

TPAIRS Defines the master slave tracer relationshipTPFA Specifies the fraction of pore volume flooded by the tracer

TPFV Sets the accessible pore volume for each tracer in the whole reservoir

TPVT Defines formation factor for field solvent and gas

TRACER Sets up tracers

VCRIT Defines the critical volumes

VCRITVIS Defines the critical volumes for the viscosity calculations

ZCRIT Defines the critical Z-factors

ZCRITVIS Defines the critical Z-factors the viscosity calculations

ZMFVD Defines the total composition with respect to depth tables


Keyword Description

58 Data File Overview FrontSim User GuideREGIONS section

REGIONS sectionThe keywords are:

Table 5.5 REGIONS keywords

Keyword DescriptionADD Adds a constant to the specified array in the current box


COPY Copies data from one array to another.

END Denotes the logical end of an input file.




ENDNUM End point scaling versus depth region numbers


EQLNUM Equilibration region numbers

FIPNUM Defines the fluid-in-place region numbers


MULTIPLY Multiply array by a constant in current box

PVTNUM Defines the PVT region numbers


ROCKNUM Rock compaction table region numbers

SATNUM Defines the saturation function region numbers.

FrontSim User Guide Data File OverviewSOLUTION section

59

SOLUTION sectionThe keywords are:

Table 5.6 SOLUTION keywords

Keyword DescriptionAQANTRC Sets initial tracer concentrations for analytic aquifersAQUANCON Specifies connection data for analytic aquifers

AQUCT Specifies the property data for Carter-Tracy aquifers

AQUFETP Specifies the property data for Fetkovich aquifers

AQUFLUX Specifies a constant flux aquifer


DATUM Datum depth for output of depth corrected pressures





EQUIL Specifies equilibration data


PBUB Defines the initial bubble point pressure

PBVD Bubble point versus depth tables for equilibration

PDEW Defines the initial dew point pressure

PDVD Dew point versus depth tables for equilibration

PRESSURE Specifies the initial pressures

RESTART Reads the solution from a RESTART file

RPTSOL Controls on output from SOLUTION section

RS Defines the initial solution gas-oil ratios

RSVD Rs versus depth tables for equilibration

RV Defines the initial vapor oil-gas ratios

RVVD Rv versus depth tables for equilibration

SGAS Specifies the initial gas saturations

SWAT Specifies the initial water saturations

TBLK Specifies the initial tracer concentrations

TIADS Specifies the initial tracer adsorbed

ZMF Specifies the cell initial total composition, explicitly.

60 Data File Overview FrontSim User GuideSUMMARY section

SUMMARY sectionThe SUMMARY section specifies a number of variables that are to be written to Summary files after each time step of the simulation. The graphics post-processor may be used to display the variation of variables in the Summary files with time and with each other. If there is no SUMMARY section, FrontSim will potentially (if the data is present) generate the same vector as for 2005A due to backward compatibility reasons.

The keywords that may be specified in the SUMMARY section are shown in the following tables. All are optional, and no significance attaches to the order in which they are specified. All keywords must start in column 1. All characters up to column 8 are significant.

The following tables Table 5.7 to Table 5.29 detail the vectors that are written to the summary files.

Table 5.7 contains details of the oil flow vectors:

Table 5.8 contains details of the water flow vectors:

Table 5.7 Well and group oil flows

Field Group Well Connection InformationFOPR GOPR WOPR COPR Oil Production Rate

COPRL Oil Production Rate in Lumped completion

FOPT GOPT WOPT COPT Oil Production Total

COPTL Oil Production Total in Lumped completion

FOPRH GOPRH WOPRH Oil Production Rate History (WCONHIST)

FOPTH GOPTH WOPTH Oil Production Total History (WCONHIST)

FOIR GOIR WOIR Oil Injection Rate

FOIT GOIT WOIT Oil Injection Total

FOIRH GOIRH WOIRH Oil Injection Rate History

Table 5.8 Well and group water flows

Field Group Well Connection InformationFWPR GWPR WWPR CWPR Water Production Rate

CWPRL Water Production Rate in Lumped completion

FWPT GWPT WWPT CWPT Water Production Total

CWPTL Water Production Total in Lumped completion

FWIR GWIR WWIR CWIR Water Injection Rate

CWIRL Water Injection Rate in Lumped completion

FWIT GWIT WWIT CWIT Water Injection Total in Lumped completion

CWITL Water Injection Total

FWPRH GWPRH WWPRH Water Production Rate History (WCONHIST)

FWIRH GWIRH WWIRH Water Injection Rate History (WCONHIST)

FWPTH GWPTH WWPTH Water Production Total History (WCONHIST)

FrontSim User Guide Data File OverviewSUMMARY section

61

Table 5.9 contains details of the gas flow vectors:

Table 5.10 contains details of the liquid flow vectors:

Table 5.11 contains details of the reservoir volume flow vectors:

Table 5.9 Well and group gas flows

Field Group Well Connection InformationFGPR GGPR WGPR CGPR Gas Production Rate

CGPRL Gas Production Rate in Lumped completion

FGPT GGPT WGPT CGPT Gas Production Total

CGPTL Gas Production Total in Lumped completion

FGIR GGIR WGIR CGIR Gas Injection Rate

CGIRL Gas Injection Rate in Lumped completion

FGIT GGIT WGIT CGIT Gas Injection Total

CGITL Gas Injection Total in Lumped completion

FGPRH GGPRH WGPRH Gas Production Rate History (WCONHIST)

FGIRH GGIRH WGIRH Gas Injection Rate History (WCONHIST)

FGPTH GGPTH WGPTH Gas Production Total History (WCONHIST)

Table 5.10 Well and group liquid flows

Field Group Well Connection InformationFLPR GLPR WLPR Liquid Production Rate

FLPT GLPT WLPT Liquid Production Total

FLPRH GLPRH WLPRH Liquid Production Rate History (WCONHIST)

FLPTH GLPTH WLPTH Liquid Production Rate History (WCONHIST)

Table 5.11 Well and group reservoir volume flows

Field Group Well Connection InformationFVPR GVPR WVPR CVPR Reservoir Volume Production Rate

CVPRL Reservoir Volume Production Rate in Lumped completion

FVPT GVPT WVPT CVPT Res Volume Production Total

CVPTL Res Volume Production Total in Lumped completion

FVIR GVIR WVIR CVIR Res Volume Injection Rate

CVIRL Res Volume Injection Rate in Lumped completion

FVIT GVIT WVIT CVIT Res Volume Injection Total

CVITL Res Volume Injection Total in Lumped completion


The ratio vectors are:

The pressure vectors are:

The Miscellaneous quantities are:

Table 5.12 Well and group production ratios

Field Group Well Connection InformationFWCT GWCT WWCT CWCT Water Cut

CWCTL Water Cut in Lumped completion

FGOR GGOR WGOR CGOR Oil-Gas Ratio

CGORL Oil-Gas Ratio in Lumped completion

FWGR GWGR WWGR CWGR Water-Gas Ratio

CWGRL Water-Gas Ratio in Lumped completion

FWCTH GWCTH WWCTH Water Cut History (WCONHIST)

FGORH GGORH WGORH Oil-Gas Ratio History (WCONHIST)

FWGRH GWGRH WWGRH Water-Gas Ratio History (WCONHIST)

Table 5.13 Well pressures etc.

Field Group Well InformationWBHP Bottom Hole Pressure

WBHPH Bottom Hole Pressure History (WCONHIST, WCONINJH)

WTHP Tubing Head Pressure

WTHPH Tubing Head Pressure (WCONHIST, WCONINJH)

WBP 1-point Pressure Average

WPI Productivity Index at reservoir conditions

Table 5.14 Miscellaneous quantities

Field Region Block InformationFGIP RGIP Gas In Place

FOIP ROIP Oil In Place

FWIP RWIP Water In Place

MG Material Balance Error Gas (Keyword MBE)

MO Material Balance Error Oil (Keyword MBE)

MW Material Balance Error Water (Keyword MBE)

MT Material Balance Error Total (Keyword MBE)

FPR RPR Pressure

FPPG RPPG Gas Potential

FPPO RPPO Oil Potential

FPPW RPPW Water Potential

FOE Field Oil Efficiency (Total oil produced / OIIP)


63

The Tracer Grid quantities are:

The Tracer Well quantities are:

The IOR Oil Rates are:

The IOR Water Rates are:

The IOR Gas Rates are:

Table 5.15 Tracer Grid quantities

Field Region Block InformationFTIPTn RTIPTn Total Tracer In Place for tracer ‘n’ (1-3 char)

FTIPFn RTIPFn Free Tracer In Place for tracer ‘n’ (1-3 char)

FTIPSn RTIPSn Absorbed Tracer In Place for tracer ‘n’ (1-3 char)

Table 5.16 Tracer Well quantities

Field Group Well InformationFTICn GTICn WTICn Tracer Injection Concentration for tracer ‘n’ (1-3 char)

FTPCn GTPCn WTPCn Tracer Production Concentration for tracer ‘n’ (1-3 char)

FTIRn GTIRn WTIRn Tracer Injection Rate for tracer ‘n’ (1-3 char)

FTPRn GTPRn WTPRn Tracer Production Rate for tracer ‘n’ (1-3 char)

FTITn GTITn WTITn Tracer Injection Total for tracer ‘n’ (1-3 char)

FTPTn GTPTn WTPTn Tracer Production Total for tracer ‘n’ (1-3 char)

Table 5.17 IOR Oil Rates

Field Group Well InformationFOPRIOR GOPRIOR WOPRIOR Oil Production Rate from IOR Oil

FOPRTO GOPRTO WOPRTO Oil Production Rate from all Sources of Oil

Table 5.18 IOR Water Rates

Field Group Well InformationWWPRCORR Well Water Production Rate Corrected for Tracer Production

WWIRCORR Well Water Injection Rate Corrected for Tracer Injection

Table 5.19 IOR Gas Rates

Field Group Well InformationFGPRIOR GGPRIOR WGPRIOR Gas Production Rate from Solution Gas from IOR Oil

WGPRRTS Well Gas Production Rate from Returned Trapped Solvent

WGPRES Well Gas Production Rate from Effective Solvent


The compositional quantities are:

The analytic aquifer quantities are:

The numerical aquifer quantities are:

WGPRIES Well Gas Production Rate from Ineffective Solvent

FGPRTS GGPRTS WGPRTS Gas Production Rate from all Sources of Solvent

WGPRRTLG Well Gas Production Rate from Returned Trapped Lean Gas

WGPRELG Well Gas Production Rate from Effective Lean Gas

WGPRIELG Well Gas Production Rate from Ineffective Lean Gas

FGPRTLG GGPRTLG WGPRTLG Gas Production Rate from All Sources of Lean Gas

FGPRTG GGPRTG WGPRTG Gas Production Rate from All Sources of Gas

WGIRES Well Gas Injection Rate from Effective Solvent

WGIRIES Well Gas Injection Rate from Ineffective Solvent

FGIRTS GGIRTS WGIRTS Gas Injection Rate from All Sources of Solvent

WGIRELG Well Gas Injection Rate from Effective Lean Gas

WGIRIELG Well Gas Injection Rate from Ineffective Lean Gas

FGIRTLG GGIRTLG WGIRTLG Gas Injection Rate from All Sources of Lean Gas

FGIRTG GGIRTG WGIRTG Gas Injection Rate from All Sources of Gas

Table 5.19 IOR Gas Rates

Field Group Well Information

Table 5.20 Compositional quantities

Field Group Well InformationFZMF GZMF WZMF Total Mole Fraction

FCHMR GCHMR WCHMR Component Hydrocarbon Molar Production Rate

FCHMT GCHMT WCHMT Component Hydrocarbon Molar Production Total

Table 5.21 Analytic aquifer quantities

Field Aquifer InformationFAQR AAQR Aquifer influx rate

FAQT AAQT Cumulative aquifer influx

AAQP Aquifer pressure (Fetkovich aquifers only).

Table 5.22 Numerical aquifer quantities

Field Aquifer InformationFNQR ANQR Aquifer influx rate

FNQT ANQT Cumulative aquifer influx

ANQP Aquifer pressure (average pressure weighted by water volume)


65

The performance quantities are:

The pattern quantities valid for both injectors and producers are:

The pattern quantities valid for injectors only are:

Table 5.23 Performance quantities

Name InformationTCPUASS CPU Usage assembling the matrix (keyword TCPU)

TCPUSOL CPU Usage pressure solver (keyword TCPU)

TCPUVT CPU Usage velocity calculation (keyword TCPU)

TCPUSAT CPU Usage saturation solver (keyword TCPU)

TCPUINI CPU Usage initialization (keyword TCPU)

TCPU CPU Usage total (sum of all above) (keyword TCPU)

TMEMPKMB Peak Memory usage (MBytes) (keyword TMEMPK)

MLINEARS Number of linear iterations used by the equation solver

NEWTON Number of non linear iterations used by the equation solver

STRA_NUM Number of added streamlines

STRD_NUM Streamline density

STRT_NUM Total number of streamlines (“added” included)

TIMESTEP Timestep Length

Table 5.24 Pattern Quantities - valid for both injectors and producers

Field Well Connection InformationWPPOREV CPPOREVL Pattern Pore Volume

FVRR WPVRR CPVRRL Pattern voidage replacement ratio.

FMOIP WPMOIP CPMOIPL Remaining mobile oil volume in pattern.

WPPR CPPRL Pattern pore volume weighted pressure

WPHCPR CPHCPRL Pattern hydrocarbon pore volume weighted pressure

WP*IP CP*IPL Pattern in-place volumes (water, oil, gas) (*=W,O,G)

FMF*R WPMF*R CPMF*RL Pattern matrix-fracture rate (total, water, oil, gas) (*=V,W,O,G)

FMF*T WPMF*T CPMF*TL Pattern matrix-fracture total (total, water, oil, gas) (*=V,W,O,G)

WPDRAIN CPDRAINL Fraction of oil drained by producer from its pattern

Calculated as WOPT/(WPOIP+WOPT)

Table 5.25 Pattern Quantities - valid for injectors only

Field Well Connection InformationFVIEFF WPVIEFF CPVIEFFL Injection efficiency. Ratio of offset hydrocarbon production rate

to total production rate at reservoir conditions.

WP*PR(*=V,W,O,G) CP*PRL(*=V,W,O,G) Pattern production rate (total volume, water, oil, gas)

WP*PT(*=V,W,O,G) CP*PTL(*=V,W,O,G) Pattern cumulative production (total volume, water, oil, gas)


The temperature well quantities are:

The temperature grid quantities are:

Table 5.28 contains details of the control modes:

WPNPROD Number of linked producers in dynamic pattern.

WPLEAK Injection not contributing to production or ‘leakage’ fraction.

WPLEAKUD Injection contributing to production outside ‘user defined’ or static pattern producers.

WPFLOOD CPFLOODL Fraction of oil swept by injector from its pattern

Calculated as WPOPT/(WPOIP+WPOPT)

Table 5.25 Pattern Quantities - valid for injectors only

Field Well Connection Information

Table 5.26 Temperature Well quantities

Field Group Well InformationFTICHEA GTICHEA WTICHEA Injection Temperature

FTPCHEA GTPCHEA WTPCHEA Production Temperature

FTIRHEA GTIRHEA WTIRHEA Heat flows (Injection)

FTPRHEA GTPRHEA WTPRHEA Heat flows (Production)

FTITHEA GTITHEA WTITHEA Heat Injection Total

FTPTHEA GTPTHEA WTPTHEA Heat Production Total

Table 5.27 Temperature Grid quantities

Field Region Block InformationFTIPTHEA RTIPTHEA Heat in place

Table 5.28 Well and group control modes

Field Group Well InformationWMCTL Mode of control

0.0=SHUT,1.0=ORAT,2.0=WRAT,3.0=GRAT,4.0=LRAT,5.0=RESV,7.0=BHP


67

Other keywordsThe keywords are:

Keyword data formatSummary vector keywords can have one of three formats:

• keyword with no data;

Table 5.29 Other keywords

Keyword DescriptionALL FOPR GOPR WOPR FOPT GOPT WOPT

FOIR GOIR WOIR FOIT GOIT WOIT

FWPR GWPR WWPR FWPT GWPT WWPT

FWIR GWIR WWIR FWIT GWIT WWIT

FGPR GGPR WGPR FGPT GGPT WGPT

FGIR GGIR WGIR FGIT GGIT WGIT

FVPR GVPR WVPR FVPT GVPT WVPT

FVIR GVIR WVIR FVIT GVIT WVIT

FWCT GWCT WWCT FGOR GGOR WGOR

FWGR GWGR WWGR

WBHP

EXCEL Requests RUNSUM output to be in Microsoft Excel format.

FMWSET Requests the set of mnemonics that counts the number of all production and injection wells in various states and under various control modes. The set also includes counts of drilling queue and workover events in a timestep and the cumulative totals of such events.

GMWSET Requests the set of mnemonics that counts the number of production and injection wells in various states and under various control modes.

The set also includes counts of drilling queue and workover events in a timestep and the cumulative totals of such events. The wells included in the counts are limited to those that are part of a named group.

MBE Will include the mass balance error report for MG, MO and MW (see "Miscellaneous quantities" on page 62).

RUNSUM Requests tabulated output of SUMMARY data in PRINT file at end of run.

SEPARATE Requests RUNSUM output to go to a separate RSM file.

TIMESTEP size of timesteps

EOPR Edge oil production rate (used with GEOFLOFS)

EOPT Edge cumulative oil production. (used with GEOFLOFS)

EWCT Edge water cut. (used with GEOFLOFS)

EWIR Edge water injection rate (used with GEOFLOFS)

EWIT Edge total water injection. (used with GEOFLOFS)


• keyword with a list of data, terminated by a slash (/). Sometimes the list can be defaulted (left blank);

• keyword followed by a set of records, each record terminated by a slash (/). A blank record is used to terminate the keyword.

Examples of these three formats are:

Keywords that begin with AKeywords that begin with the letter 'A' are followed by a list of analytic aquifer numbers terminated by a slash (/).

For example,

specifies that analytic aquifers 1 and 2 are to be stored in the summary files. If a null list of aquifers is specified, data is stored in the summary file for all analytic aquifers.

The keyword ALL is an exception to this rule. There is no data associated with it.

Keywords that begin with CKeywords that begin with the letter 'C' must be followed by a list of well-reservoir connections (the well name and the three block coordinates). Each connection must be specified on a fresh line and terminated by a slash (/). The three grid block coordinates may be defaulted for a well, which will cause the appropriate quantity to be output for all connections in the well. The list of well connections is terminated by a line beginning with a slash (/).

For example,

Keywords beginning with the letter 'C' and ending with the letter 'L' output the corresponding connection quantity totalled over all the connections that belong to the same lumped completion (see keyword COMPLUMP). Any connection within the lumped completion can be specified to define the completion.

Keywords that begin with FAll other keywords that begin with the letter 'F' have no associated data.

FPR

WBHPWELL1 WELL2 WELL3 /

COFR'PROD1' 10 3 7 /'PROD1' 10 3 8 //

AAQR1 2 /

COFR'PROD1' 10 3 7 /'PROD1' 10 3 8 /'PROD2' 4 2 5 /'PROD3' //


69

Keywords that begin with G or WKeywords that begin with 'G' or 'W' must be followed by a list of well or group names enclosed in quotes. The list is terminated by a slash (/).

For example,

specifies that the water cut for the three named groups of wells are to be stored on the summary files.

If a null list is specified, data is stored for all groups or wells.

For example,

A well name or well list template containing wildcard characters may be supplied to a keyword beginning with the letter 'W'.

Keywords that begin with RKeywords which begin with the letter 'R' (for example RWIP) are followed by a list of fluid-in-place region numbers which is terminated by a single slash (/). The region numbers are not organized in pairs.

For example,

specifies that the oil in place in regions 5, 6 and 8 is to be stored in the summary files. If a null list of regions is specified, data is stored in the Summary file for all regions.

For example,

Keywords that begin with WThese are described in "Keywords that begin with G or W" on page 69.

GWCT'PLAT1' 'PLAT2''PLAT3'/

WBHP/

ROIP5 6

8 /

RGIPG/


Keywords that end in HThe keywords that end with the letter H (for example WOPRH, WWPRH, WGPRH, WWCTH, WGORH, WOGRH, WWGRH) refer to the observed production/injection history of history matching wells specified in keywords WCONHIST and WCONINJH. These quantities are included to enable you to compare, for example, the calculated water cut WWCT with the observed water cut WWCTH. They are ignored if applied to wells that are not history matching wells. Group and field keywords ending in H (for example GOPRH, FWPRH) refer to the sum of their subordinate well flows, with the flows of all history matching wells replaced with their historical rates specified in WCONHIST and WCONINJH. Thus, for example, FWCT can be compared with FWCTH to determine how well the field water cut matches its observed value.

Keywords that provide information at a component level must have the component number appended to any other data associated with the keyword. For group type keywords a line of data must contain a single group name followed by a component number terminated by a slash (/). For well type keywords a line of data can either contain a single well name or a well name template containing wildcard characters, followed by a component number and terminated by a slash (/). If a well name template is supplied then it will be matched during the simulation period.

When rates and totals are being reported for groups or wells at a component level, they are positive for production and negative for injection.

For example,

or, to get the 7th, 8th and 9th component values of BXMF at grid block (21,7,13),

or (note that this format is different from that used for keywords beginning with B or W):

The mnemonic name written to the Summary file has the component index appended after an additional underscore character (for example, WXMF_7). In rare cases the underscore will be omitted to ensure the composite name does not exceed 8 characters (for example, although the molar rate of component 3 in the gas from the 2nd separator stage of a well is written as WCGMR2_3, the molar rate of component 15 has to be written as WCGMR215).

WXMF'PROD1' 7 //

BXMF21 7 13 7 /21 7 13 8 /21 7 13 9 //

FZMF1 /FZMF2 /FZMF3 /


71

Example SUMMARY sectionHere is an example of a context-independent SUMMARY section:

SUMMARY ===========================================================-- Field oil prod rate.-- Cumulative oil prod for field and for every well.FOPRFOPTWOPT/--Field wat inj rate. Cumulative wat inj for field and for every well.FWIRFWITWWIT/--Field gas inj rate. Cumulative gas inj for field and for every well.FGIRFGITWGIT/-- Instantaneous GOR for field and for every well.FGORWGOR/-- Instantaneous water cuts for field and for every well.FWCTWWCT/-- Oil in place for field and for every FIP region.FOIPROIP/


-- Water in place for field and for every FIP region.FWIPRWIP/-- Gas in place for field and for every FIP region.FGIPRGIP/-- Average pressure for field and for every FIP region.FPRRPR/-- Aquifer influx rate for field and every analytic aquifer.FAQRAAQR/

FrontSim User Guide Data File OverviewSCHEDULE section

73

SCHEDULE sectionThe keywords are:

Table 5.30 SCHEDULE keywords

Keyword DescriptionAQUFLUX Specifies a constant flux aquifer


CECON Economic limits for production well connections

CECONINJ Economic limits for injection well connections

COMPDAT Specifies the properties of well completions

COMPDATL Specifies the properties of well completions in local grid refinements

COMPLUMP Lumps connections for automatic workovers (only for summary output)

DATES Specifies a list of dates at which reports are required

DRSDT Maximum rate of increase of solution GOR

DRVDT Maximum rate of increase of vapor OGR





FLUXSIDE Specifies the flux boundary condition

FSSOLVE Specifies equation solver

FSWEAKW Reduces material balance errors

GCONINJE Specifies the injection rate controls and limits for groups and the field

GCONPROD Specifies the production rate controls and limits for groups and field

GECON Specifies the economic limit data for groups and the field

GOCADOUT JACTA-compatible output file to be generated

GUIDERAT Specifies the general formula for guide rates


MAXSTEP Sets a maximum value for subsequent timesteps

MINSTEP Sets a minimum value for subsequent timesteps

MISUPPLY Describes field IOR solvent supply limit

NEXTSTEP Sets a maximum value for the next timestep

NOSIM Turn off simulation

OPTIONFS Activates special program options

PNODE Specifies the pressure boundary condition

PRODLIM Describes water and gas supply daily limit for the fieldPSIDE Sets a pressure boundary condition over an areaPSIDEH Sets a hydrostatic pressure boundary condition over an area

74 Data File Overview FrontSim User GuideSCHEDULE section

RANKING Triggers different options for ranking of the solvent allocation

RANKWELL Assignment of mobilization curves to solvent injection wells


RPTALLOC Controls on output to the .ALN file

RPTLINFS Sets report frequency for line graph output

RPTPRINT Controls the output of printed reports

RPTRST Controls on output to the RESTART file

RPTSCHED Controls on output from SCHEDULE section

RPTSLN Controls on output to the SLN file

SOLVSLUG Describes solvent allocation functionality

SKIPREST Skip subsequent keywords in a restart run until the restart time is reached

TSCRITFS Describes user control of time stepping algorithm

TSTEP Advances the simulator to new report times

TUNEFS1D Sets the tuning options for the 1D solver used for 3-phase and compositional runs

TUNEFSPR Sets simulator control parameters

TUNEFSSA Sets the tuning options for the saturation solver

VFPINJ Inputs a VFP table for injection wells

VFPPROD Inputs a VFP table for production wells

WCONHIST Defines the observed flow rates for history matching wells

WCONINJ Defines the injection well control data, with no group control

WCONINJE Defines the control data for injection wells

WCONINJH Observed rates for history matching injection wells

WCONINJP Control data for pattern flood injection wells

WCONPAT Keyword for pattern flood management

WCONPEND Switch off Injection Rate Optimization

WCONPROD Defines the control data for production wells

WECON Defines the economic limit data for production wells

WECONINJ Economic limit data for injection wells

WEFAC Sets well efficiency factors (for downtime)

WELPI Sets well productivity/injectivity index values

WELLSTRE Sets the composition of the injection gas stream

WELOPEN Shuts or reopens wells or well connections

WELSPECL Specifies general data for wells in local grid refinements

WELSPECS Specifies general data for wells

WELSTRDN Sets the stream density for a well

WELTARG Resets a well operating target or limit

WFRICTN Designates a well as a friction well


Keyword Description

FrontSim User Guide Data File OverviewSCHEDULE section

75

WINJGAS Specifies the nature of injection gas

WPAVE Well block average pressure controls

WPAVEDE Reference depth for well block average pressure calculation

WPIMULT Multiplies well connection factors by a given value

WRFTPLT Requests output of well RFT and PLT data to the RFT file

WSOLVENT Sets solvent fraction for gas injection wells

WTEMP Sets the temperature of a water injection well

WTEST Instructions for periodic testing of closed wells

WTMULT Multiplies a well operating target or limit

WTRACER Sets tracer concentrations for injection wells.


Keyword Description

76 Data File Overview FrontSim User GuideSCHEDULE section

FrontSim User Guide KeywordsACF

77

Chapter 6Keywords

A

ACF Acentric factor In a run with components, using an equation of state, this keyword defines the acentric factor for each component. The keyword should be followed by values. The use of the acentric factor in the equation of state is discussed in "Equations of State" in the "FrontSim Technical Description".

Note FrontSim currently handles only a single EoS region.

Examples

Example 1

ECLIPSE 100x ECLIPSE 300

SPECIALx FRONTSIM

RUNSPECGRIDEDIT

x PROPSREGIONSSOLUTIONSUMMARYSCHEDULE

ACF0.01 0.0 0.02 0.001 /

Nc

Nc

78 Keywords FrontSim User GuideACTNUM

ACTNUM Active grid block identificationThe keyword should be followed by one integer for every grid block in the current box.

A value of 1 indicates that the corresponding grid block is active, whilst a 0 indicates that it is inactive. The data must be terminated by a slash(/).

It should be noted that this is only one of a number of ways of identifying inactive grid blocks. Other possibilities include setting the porosity (PORO), or net to gross thickness ratio (NTG), to zero in the GRID section.

Indeed, any method that results in zero pore volume causes a grid block to be treated as inactive. For example, the MINPV keyword can be used to set a minimum threshold pore volume, so that any grid blocks having a pore volume smaller than this, are treated as inactive.

Grid blocks are ordered with the X axis index cycling fastest, followed by the Y and Z axis indices. Repeat counts may be used for repeated values (for example 12*0). Note that spaces must not be inserted on either side of the asterisk.

ExampleWith NDIVIX=8, NDIVIY=6, NDIVIZ=3:

x ECLIPSE 100x ECLIPSE 300

SPECIALx FRONTSIM

RUNSPECx GRID

EDITPROPSREGIONSSOLUTIONSUMMARYSCHEDULE

ACTNUM0 0 0 1 1 1 0 00 1 1 1 1 1 0 01 1 1 1 1 0 0 00 1 1 1 1 1 1 10 0 1 1 0 1 1 10 0 1 0 0 1 1 00 0 0 1 1 1 0 00 0 0 1 1 1 0 01 1 0 0 1 0 0 00 1 1 1 1 1 1 10 0 1 1 0 1 0 10 0 1 0 0 0 0 00 0 0 1 1 1 0 00 0 0 0 0 1 0 11 1 0 0 0 0 0 11 1 1 1 1 1 1 11 1 1 1 1 1 1 10 0 1 0 0 1 1 1 /

FrontSim User Guide KeywordsADD

79

ADD Adds a constant to the specified array in current boxThe keyword may be followed by any number of records, each of which is terminated by a slash (/). The data is terminated by a null record (that is, a record with no data before the terminating slash(/)).

Each record consists of at least 2, and up to 8 items of data:

1 The name of the array to be modified

2 The constant to be assigned to the array specified by item 1

The constant must be an integer if the array contains integer region numbers (for example, FIPNUM). The constant may be real if the array contains real data (for example TRANX).

Items 3-8 define the limits of a box within the grid over which the value is to be added.

These items may be used to redefine the input box for this and subsequent operations within the current keyword. The values are used until reset or until the end of the keyword.

If items 3-8 are not defined (a slash is inserted after item 2), they default to the values which were used for the previous operation within the current keyword.

For the first operation in the keyword, the box defaults to the values set by the most recent BOX or ENDBOX keyword. If there is no preceding BOX or ENDBOX in the current section, the box is taken to include the entire reservoir.

3 First block to be modified on the X axis (IX1)

4 Last block to be modified on the X axis (IX2)

5 First block to be modified on the Y axis (JY1)

6 Last block to be modified on the Y axis (JY2)

7 First block to be modified on the Z axis (KZ1)

8 Last block to be modified on the Z axis (KZ2)

The data must satisfy:

1 ≤ IX1 ≤ IX2 ≤ NDX

1 ≤ JY1 ≤ JY2 ≤ NDY

1 ≤ KZ1 ≤ KZ2 ≤ NDZ,

where NDX, NDY, NDZ are the limits in the current BOX.

Notes • In the REGIONS section only integer values should be used

• The added quantity may be negative, in order to subtract

• The use of the ADD keyword assumes that a value has already been assigned to the array, either explicitly, or using the EQUALS keyword

• The ADD, COPY, EQUALS and MULTIPLY keywords are processed as they are read, so that repeated operations are possible

• See also the keywords BOX, ENDBOX, EQUALS, MULTIPLY and COPY.


SPECIALx FRONTSIM

RUNSPECx GRIDx EDITx PROPSx REGIONS

SOLUTIONSUMMARYSCHEDULE

80 Keywords FrontSim User GuideADD

Examples

Example 1In the REGIONS section:

Example 2In the EDIT section:

-------- ARRAY CONSTANT ----- BOX -----ADD

SATNUM 3 1 11 1 19 2 2 /PVTNUM 1 / defaults to last specified boxEQLNUM 1 / defaults to last specified box

FIPNUM 8 / defaults to last specified box/

-------- ARRAY CONSTANT ----- BOX -----ADD

PORV 350. 0 1 11 1 19 2 2 /DEPTH 1 / defaults to last specified boxTRANX 1 / defaults to last specified box

/

FrontSim User Guide KeywordsAQANTRC

81

AQANTRC Sets initial tracer concentrations for analytic aquifersThis keyword is used to specify the value of the initial concentration of a water phase tracer in each of the analytic aquifers in the run. Refer to the keywords AQUFETP, AQUCT and AQUFLUX.

Caution The AQANTRC keyword can only appear after any of the keywords AQUFETP, AQUCT or AQUFLUX has been used to define the aquifer types.

If a tracer is not specified in the list of tracer names, a default concentration value of 0.0 is assumed.

The keyword is followed by any number of records, each containing the following items of data:

1 Aquifer identification number.

This should be a valid aquifer number between 1 and the maximum number of aquifers, defined in the input data.

2 Name of the tracer.

The tracer must have been previously defined to exist in the water phase (see keyword TRACER in the PROPS section).

3 Value of the initial tracer concentration in the aquifer.

This item should lie in the range 0 to 1.

Each data record ends with a slash (/), and the set of records with a blank record, containing just a slash (/).

Examples

Example 1With 2 aquifers defined:

Example 2Set 60% concentration of TR6 in the first aquifer.


SPECIALx FRONTSIM

RUNSPECGRIDEDITPROPSREGIONS

x SOLUTIONSUMMARYSCHEDULE

AQANTRC1 WT1 1.0 /1 WT2 0.0 /2 WT1 0.0 /2 WT2 1.0 //

AQANTRC1 TR6 0.6 //

82 Keywords FrontSim User GuideAQUANCON

AQUANCON Specifies connection data for analytic aquifersAQUANCON connects analytic aquifers (declared using AQUCT, AQUFETP, AQUNUM or AQUFLUX) to one or more reservoir cells.

Caution The AQUANCON keyword can only appear after the aquifer properties have been defined, by one of the keywords AQUCT, AQUFETP, AQUFLUX or AQUNUM.

The connection to the reservoir is set up by an arbitrary box defined by lower and upper I, J and K indices. For each active grid block within the box, an aquifer connection is made to the face specified in item 8 if either of the following conditions is met:

• the face is on the outside of the reservoir, or

• the face adjoins an inactive cell.

Any number of records may be entered, each terminated with a slash (/). The set of records must be terminated with a blank record containing just a slash.

The items in each record are:

1 Aquifer identification number

2 Lower I-location of connecting grid blocks

3 Upper I-location of connecting grid blocks

4 Lower J-location of connecting grid blocks

5 Upper J-location of connecting grid blocks

6 Lower K-location of connecting grid blocks

7 Upper K-location of connecting grid blocks

8 Index defining the face of the reservoir to which the aquifer connects:

9 The aquifer influx coefficient.

This item multiplied by the value given at item 10 defines the weighted influx coefficient for each cell in the input box defined in items 2-7.

The weighted influx coefficient for each cell face divided by the sum of the weighted influx coefficients for all cell faces connected to an aquifer determines the proportion of the total influx into that cell face from that aquifer.

FrontSim Each cell face may be assigned only one influx coefficient. If a cell face is defined more than once, the last value entered will be used.

ECLIPSE If a reservoir cell is defined more than once, its previous value for the aquifer influx coefficient is added to the present value. The exception is the case where you enter a zero value, which then sets the influx coefficient for all the cells in the box to zero.


SPECIALx FRONTSIM



I- I = 1 face

I+ I = NDIVIX face

J- J = 1 face

J+ J = NDIVIY face

K- K = 1 face (top)

K+ K = NDIVIZ face (bottom)

FrontSim User Guide KeywordsAQUANCON

83

Influx coefficients should not be all zero for a given aquifer. ECLIPSE 100 and FrontSim

The aquifer influx coefficient is not used if the aquifer is a constant flux aquifer (keyword AQUFLUX). A negative value is not accepted.

• DEFAULT: For each cell in the input box, the default is its face area.

ECLIPSE 100 and FrontSim

10 Aquifer influx coefficient multiplier.

The multiplier is applied to the influx coefficients of the aquifer - cell connections within the box.

For constant flux aquifers (keyword AQUFLUX) the multiplier is applied to the cell areas.

• DEFAULT: 1.0

Note The influx coefficient for analytic aquifers is not affected by MULTX, Y, Z. See MULTX, MULTY and MULTZ.

ExampleOne Carter-Tracy aquifer, connected to two vertical sides of a 10 x 10 x 2 grid with one face where the aquifer influx coefficient is set to 1000.

AQUCT1 7000.0 4000.0 200.0 .3 1.0E-5 500.0 50.0 10.0 1 1 //AQUANCON1 1 10 10 10 1 2 'J+' /1 10 10 1 10 1 2 'I+' 1000. //

84 Keywords FrontSim User GuideAQUCT

AQUCT Specifies the property data for Carter-Tracy aquifers This keyword specifies Carter-Tracy aquifers.

Note An aquifer should not be re-specified.

Each record refers to a separate Carter-Tracy aquifer and contains the following items of data:


2 Datum depth

• UNITS: METRIC: m, FIELD: ft

3 Initial aquifer pressure at the datum depth

If this quantity is defaulted or given a negative value, the initial pressure is calculated to place the aquifer as nearly as possible in equilibrium with the reservoir.

• UNITS: METRIC: bars, FIELD: psia

4 Permeability of the aquifer

• UNITS: METRIC: mD, FIELD: mDm

5 Porosity of the aquifer

• DEFAULT: 1.0

6 Total (rock + water) compressibility of the aquifer

• UNITS: METRIC: 1/bars, FIELD: 1/psi

7 External radius of reservoir or the inner radius of the aquifer


8 Thickness of the aquifer


9 Angle of influence (the angle subtended by the boundary between the reservoir and the aquifer)

• UNITS: METRIC: degrees, FIELD: degrees

• DEFAULT: 360.0 degrees

10 Table number for water pressure properties

(see keyword PVTW)

• DEFAULT: Table 1

11 Table number for influence functions, which are the dimensionless time and pressure values (see the AQUTAB keyword)

• DEFAULT: Table 1

Table 1 is the constant terminal rate case for an infinite aquifer as given by Van Everdingen and Hurst. This table is automatically supplied by the simulator.

Each record is terminated with a slash (/). The set of records must be terminated with a blank record containing just a slash character.


SPECIALx FRONTSIM



FrontSim User Guide KeywordsAQUCT

85

Connections to a Carter-Tracy aquifer defined by this keyword are read in by the AQUANCON keyword, which allows more than one face of the reservoir to be connected to a Carter-Tracy aquifer.

The keyword AQUCT must not be used in restarted runs, as the aquifer specification data cannot be changed.

ExampleOne Carter-Tracy aquifer, connected to two vertical sides of a 10 x 10 x 2 grid:

AQUCT1 7000.0 4000.0 200.0 .3 1.0E-5 500.0 50.0 10.0 1 1 //AQUANCON1 1 10 10 10 1 2 'J+' /1 10 10 1 10 1 2 'I+' //

86 Keywords FrontSim User GuideAQUFETP

AQUFETP Specifies the property data for Fetkovich aquifersThis keyword specifies Fetkovich aquifers.

Each record specifies the properties of a separate Fetkovich aquifer (ranging from 1 to the number of analytic aquifers), and contains the following items of data:


This should be a number between 1 and the maximum number of aquifers.

2 Datum depth


3 Initial aquifer pressure at the datum depth

If this quantity is defaulted or given a negative value, the initial pressure is calculated to place the aquifer as nearly as possible in equilibrium with the reservoir.

• UNITS: METRIC: bars, FIELD: psia

4 Initial volume of water in the aquifer

• UNITS: METRIC: sm3, FIELD: stb

5 Total (rock + water) compressibility of the aquifer

• UNITS: METRIC: 1/bars, FIELD: 1/psi

6 Aquifer productivity index

(total influx rate per unit pressure difference)

• UNITS: METRIC: sm3/day/bars, FIELD: stb/day/psi

7 Table number for water pressure properties

(see keyword PVTW).

Each record should be terminated with a slash (/). The set of records should be terminated with a blank record containing just a slash.

Connections to a Fetkovich aquifer defined by this keyword are read in by the AQUANCON keyword, which allows more than one face of the reservoir to be connected to a Fetkovich aquifer.

The aquifer productivity index is apportioned between the connecting grid blocks in proportion to their influx coefficients, as defined in Item 9 of keyword AQUANCON.

AQUFETP must not be used in restarted runs, as the aquifer specification data cannot be changed.


SPECIALx FRONTSIM



FrontSim User Guide KeywordsAQUFETP

87

ExampleOne Fetkovich aquifer, connected to two vertical sides of a 10 x 10 x 2 grid:

AQUFETP1 7000.0 4000.0 2.0E9 1.0E-5 500.0 1 //AQUANCON1 1 10 10 10 1 2 'J+' /1 10 10 1 10 1 2 'I+' //

88 Keywords FrontSim User GuideAQUFLUX

AQUFLUX Specifies a constant flux aquiferThe keyword contains records that specify the properties of the defined aquifers.

Each record should be terminated with a slash (/). The set of records must be terminated with a blank record containing just a slash.

Each record specifies the properties of a separate aquifer and contains the following items of data:


2 Aquifer flux

This is the water inflow rate per unit area of connected cell face.

• UNITS: sm3/day/m2(METRIC), stb/day/ft2 (FIELD)

The grid block connections to each constant flux aquifer defined by this keyword must be specified by the AQUANCON keyword.

The water flow rate into a grid block from a constant flux aquifer is given by:

[EQ 6.1]

where

is the flux, entered in item 2

is the area of the connected cell face

is the aquifer influx multiplier (item 10 of the AQUANCON keyword), which defaults to 1.0.

The area is calculated directly from the connected cell geometry, and is not affected by the 9th item of the AQUANCON keyword.

The aquifer flux can be modified at any time during the simulation by re-entering the AQUFLUX keyword in the SCHEDULE section.

ExampleTwo constant flux aquifers, connected to two vertical sides of a 10x10x4 grid.


SPECIALx FRONTSIM


x SOLUTIONSUMMARY

x SCHEDULE

AQUFLUX1 0.0003 /2 0.0004 //

AQANCON-- Aquifer 11 1 10 10 10 1 4 'J+' /1 10 10 6 10 1 4 'I+' /-- Aquifer 22 10 10 6 10 1 4 'I+' //

Qw Fw A M⋅ ⋅=

Fw

A

M

FrontSim User Guide KeywordsAQUCON

89

AQUCON Specifies connection data for numerical aquifersAQUCON connects a numerical aquifer (declared using the AQUNUM keyword) to one or more reservoir cells. The connection to the reservoir is set up by an arbitrary box defined by lower and upper I, J and K indices.

Caution The AQUCON keyword must appear after the aquifer properties have been defined, by the keyword AQUNUM.

For each active grid block within the box, an aquifer connection is made to the face specified in item 8 if either of the following conditions are met:

• The face is on the outside of the reservoir, or

• The face adjoins an inactive cell.

Any number of records may be entered, each terminated with a slash (/). The set of records must be terminated with a blank record containing just a slash.

The items in each record are:


2 Lower I-coordinate of cells to be connected

3 Upper I-coordinate of cells to be connected

4 Lower J-coordinate of cells to be connected

5 Upper J-coordinate of cells to be connected

6 Lower K-coordinate of cells to be connected

7 Upper K-coordinate of cells to be connected

8 Face of the cell to be connected to the aquifer.

This should be one of I+, I-, J+, J-, K+ or K-, where K+ for instance means the bottom face.

9 Transmissibility option

The multiplier enables the calculated transmissibility value to be multiplied by a user-defined factor, for example in history matching.

• DEFAULT: 1

The transmissibility between the numerical aquifer and grid block is calculated as follows:

[EQ 6.2]

where

= Component of transmissibility from the grid block

= Component of transmissibility from the aquifer

In the cartesian case:

[EQ 6.3]


SPECIALx FRONTSIM

RUNSPECx GRID


T 11 Ta⁄( ) 1 Tc⁄( )+

---------------------------------------=

Tc

Ta

TcKc Ac NTG⋅ ⋅

Dc--------------------------------=

90 Keywords FrontSim User GuideAQUCON

where

= Cell permeability in the appropriate direction

= Cell face area

= The cell net-to-gross ratio if the cell face X or Y.

= Distance from the cell centre to the face

[EQ 6.4]

where

= Aquifer permeability from AQUNUM

= Aquifer area from AQUNUM

= Half the aquifer length from AQUNUM

Examples

Example 1An example is the connection of aquifer number 2 to all the cells in the first three J-K planes with a free face in the I- direction. This attaches the aquifer to the reservoir face, even if there are inactive cells between the grid edge and the reservoir. It is assumed the grid has NX=20, NY=20, NZ=10.

Example 2In the following, aquifer 1 is connected to cells in the first three layers of the fifth column of an X-Z cross-section. The I+ face is used, so connections are only made if the corresponding cells of column 6 are inactive, or if NDIVIX is 5.

AQUCON2 1 3 1 20 1 10 'I-' 1.0 //

AQUCON1 5 5 1 1 1 3 'I+' 1.0 //

Kc

Ac

NTG

Dc

TaKa Aa⋅

Da----------------=

Ka

Aa

Da

FrontSim User Guide KeywordsAQUNUM

91

AQUNUM Assigns a numerical aquifer to a blockThis keyword specifies blocks representing one-dimensional numerical aquifers. One or more aquifers may be set up. Each line of AQUNUM declares that a given grid block is to represent a numerical aquifer. This enables its properties (such as initial pressure, volume, etc.) to be independent of its size and position in the grid. To complete the description of the aquifer, connections to other blocks may be made using the AQUCON keyword.

The arguments of AQUNUM are as follows:


This should ideally be between 1 and the total number of aquifers defined. However, an error will result only if two aquifers are given the same number.

2 I-coordinate of grid block to represent aquifer

3 J-coordinate of grid block to represent aquifer

4 K-coordinate of grid block to represent aquifer

5 Cross-sectional area

This may be larger than can be accommodated within the grid block I,J,K. However, the position of the grid block on graphical displays is unchanged.

• UNITS: m2 (METRIC), ft2 (FIELD)

6 Length

This may be larger than can be accommodated within the grid block I,J,K.

• UNITS: m (METRIC), ft (FIELD)

7 Porosity

• DEFAULT: Grid cell value

8 Permeability

• UNITS: mD (METRIC, FIELD

9 Aquifer depth

This may differ from the geometric position in the reservoir. It may be defaulted, in which case the grid block depth is obtained.


10 Initial pressure

This may be specified explicitly or defaulted. If defaulted, the initial pressure is set by the equilibration procedure to be in hydrostatic equilibrium with the reservoir. The default procedure is recommended except in the case in which all initial pressures are entered by the user.

• UNITS: barsa (METRIC), psia (FIELD)

11 PVT table number for aquifer

• DEFAULT: Block PVTNUM value.

12 Saturation table number for aquifer

• DEFAULT: Block SATNUM value.

Each record is terminated with a slash (/). The set of records must be terminated with a blank record containing just a slash character.


SPECIALx FRONTSIM

RUNSPECx GRID


92 Keywords FrontSim User GuideAQUNUM

Notes• The length, cross-sectional area and porosity are used to calculate the aquifer volume. The

length, cross-sectional area and permeability are used to calculate the aquifer transmissibility.

• The table number used for flow into the aquifer will be that used for normal grid flows.

• In dual porosity runs the aquifer should be placed in the lower half (that is the fracture part) of the grid.

• The aquifer pore volume is calculated from the data entered in the AQUNUM keyword in all cases using

[EQ 6.5]

where the porosity is taken from the grid block value if defaulted.

ExampleIn the following example a four cell aquifer is defined, with default porosity, depth and initial pressure. Aquifer-grid connections are made to the first cell specified with a given aquifer number.

AQUNUM1 7 1 1 1.0E+5 20000 1* 200.0 2* 1 1 /1 8 1 1 1.0E+5 20000 1* 200.0 2* 1 1 /1 9 1 1 1.0E+5 20000 1* 200.0 2* 1 1 /1 10 1 1 1.0E+5 20000 1* 200.0 2* 1 1 //

PORV Porosity Length Area⋅ ⋅=

FrontSim User Guide KeywordsAQUTAB

93

AQUTAB Influence function tables for Carter-Tracy aquifers The number of influence function tables is defined in the input data.

These tables are of dimensionless time and pressure, each terminated by a slash (/).

The first table is the default table that cannot be changed. Table 1 is defined and reserved for the constant terminal rate case for an infinite aquifer as given by Van Everdingen and Hurst.

The remaining tables entered using this keyword are numbered from 2 onwards.

Each table consists of 2 columns of data:

1 Dimensionless time

Values should be greater than 0 and should increase monotonically down the column.

2 The corresponding dimensionless pressure

Values should be greater than 0.

There must be the same number of entries in each column of a given table.

ExampleExample with two influence function tables. The first is the default table, and the second is read in with AQUTAB.


SPECIALx FRONTSIM

RUNSPECGRIDEDIT


AQUTAB0.01 0.1120.05 0.2290.1 0.3150.15 0.3760.2 0.4240.25 0.4690.3 0.5030.4 0.5640.5 0.6160.6 0.659/

94 Keywords FrontSim User GuideBIC

BBIC Binary interaction coefficients

In a run with components, using an equation of state, this keyword defines the binary interaction coefficients between the components.

The keyword should be followed by values, where is the number of components specified in the RUNSPEC section with the COMPS keyword. The values are arranged in lower triangular form, the symmetry of the interaction coefficients being used to define the upper triangular part, and the self binary interaction coefficients being zero.

The use of the binary interaction coefficients in the equation of state is discussed in "Equations of State" in the "FrontSim Technical Description".


• DEFAULT: 0 (for all values)

ExampleFor a five-component system with a binary interaction coefficient of 0.01 between component pairs 1-2 and 1-3; 0.02 between components 1-4; 0.005 between pairs 2-3 and 4-5; and 0.001 between pairs 1-5, 3-4 and 3-5.


SPECIALx FRONTSIM

RUNSPECGRIDEDIT


BIC0.010.01 0.0050.02 0.0 0.0010.001 0.0 0.001 0.0005 /

Nc

Nc Nc 1–( ) 2⁄ Nc

FrontSim User Guide KeywordsBOX

95

BOX Re-defines the current input box The keyword should be followed by six integers which re-define the current input box. Subsequent operations using EQUALS, ADD, MULTIPLY and COPY only alter grid blocks within the current input box. Similarly, data read into an array (for example, using PERMX or SATNUM) are assigned to the grid blocks in the current input box.

The keyword should be followed by the data items described below, terminated with a slash.

1 First block on X axis of the new input box (IX1)

2 Last block on X axis of the new input box (IX2)

3 First block on Y axis of the new input box (JY1)

4 Last block on Y axis of the new input box (JY2)

5 First block on Z axis of the new input box (KZ1)

6 Last block on Z axis of the new input box (KZ2)


1 ≤ IX1 ≤ IX2 ≤ NDIVIX

1 ≤ JY1 ≤ JY2 ≤ NDIVIY

1 ≤ KZ1 ≤ KZ2 ≤ NDIVIZ.

The default cell limits are the current BOX values.

The data should be terminated by with a slash (/).

Note that at the end of each input section (GRID, EDIT, PROPS, and so on), the program effectively supplies an ENDBOX, and resets the input box.

See also keywords ADD, COPY, ENDBOX, EQUALS, MULTIPLY.

Example


SPECIALx FRONTSIM

RUNSPECx GRIDx EDITx PROPSx REGIONSx SOLUTION

SUMMARYx SCHEDULE

-- IX1-IX2 JY1-JY2 KZ1-KZ2BOX

3 7 4 13 3 5 /

96 Keywords FrontSim User GuideCARFIN

CCARFIN Specifies a cartesian local grid refinement

The CARFIN keyword is used to set up a local grid refinement. It specifies a cell or a box of cells identified by its global grid coordinates I1-I2, J1-J2, K1-K2 to be replaced by refined cells. The dimensions of the refined grid within this box are specified as NX, NY, NZ.

The CARFIN keyword is followed by up to twelve items of data, terminated by a slash (/). If Item 12 is used, place a 1* for Item 11:

1 Name of the local grid refinement (up to 8 characters).

2 I1 Lower I-coordinate of the box in the parent grid.

3 I2 Upper I-coordinate of the box in the parent grid.

4 J1 Lower J-coordinate of the box in the parent grid.

5 J2 Upper J-coordinate of the box in the parent grid.

6 K1 Lower K-coordinate of the box in the parent grid.

7 K2 Upper K-coordinate of the box in the parent grid.

8 NX Number of refined cells along the X-direction.

9 NY Number of refined cells along the Y-direction.

10 NZ Number of refined cells along the Z-direction.

Required but not used by FrontSim

11 1*

12 Name of parent LGR - up to 8 characters. This item may be set to either a null string or to the string GLOBAL to indicate that the parent grid is global (that is, this is not a nested refinement).

Nested refinements may be used. If the parent grid is already an LGR then the name of the parent LGR should be specified. The range of I-, J- and K- indices should then refer to the parent grid. If the parent grid is the global grid, then the range of I-, J- and K- indices refers to the global grid.

ECLIPSE 100 Nested refinements cannot be used in ECLIPSE 100 if the parent or child is part of an amalgamated local grid. They also cannot be used with the Parallel or Gradient options.

• DEFAULT: 'GLOBAL'

The number of refinement cells must be a multiple, in each direction, of the number of cells to be refined.

When a CARFIN keyword is read, the current input BOX becomes the local grid. Any other GRID section keywords (for example, PORO, etc.) following the CARFIN keyword is taken to apply to this local refinement, until an ENDFIN or other CARFIN keyword is encountered.

FrontSim only Note An LGR placed next to a fault or across a fault is not allowed in FrontSim.

See also keyword NXFIN etc.

x ECLIPSE 100x ECLIPSE 300x SPECIALx FRONTSIM

RUNSPECx GRID


FrontSim User Guide KeywordsCARFIN

97

Examples

Example1

Example 2Nested refinement in ECLIPSE 300

CARFIN--Name I1 I2 J1 J2 K1 K2 NX NY NZ

REF1 19 19 3 3 1 2 3 1 6 /--Enter data for this local gridPORO0.25 0.28 0.21 0.225 0.23 0.180.17 0.15 0.22 0.165 0.17 0.160.20 0.21 0.19 0.120 0.15 0.17 /ENDFIN

--Define a local grid REF1CARFIN--Name I1 I2 J1 J2 K1 K2 NX NY NZ NWMAX PARENT

REF1 10 19 3 3 1 4 4 4 16 1* GLOBAL /ENDFIN--Define a local grid REF2 contained within REF1CARFIN--Name I1 I2 J1 J2 K1 K2 NX NY NZ NWMAX PARENT

REF2 2 3 2 3 1 8 4 4 16 1* REF1 /--Enter data for this local grid here if requiredENDFIN

98 Keywords FrontSim User GuideCECON

CECON Economic limits for production well connectionsCECON is used to set economic limits for production well connections. If an individual connection violates one of its economic limits it will be automatically closed. The well connections must already be defined before this keyword can be used.

CECON is followed by any number of records, described below, each record terminated by a slash (/). A record may be terminated early at any item; the remaining items assume their default values. Default values can be specified before the slash by a null repeat count of the form n*, where n is the number of consecutive items to be defaulted.

The set of records must end with a blank record, containing only a slash (/).

Each record can contain up to 13 items:

1 Well name, well name template or well list

An asterisk (*) can be used to refer to multiple wells. Well list names should begin with an asterisk (*). Well lists are constructed with the keyword WLIST.

2 I - location of connecting grid block(s)

• DEFAULT: 0 (allows any I-value)

3 J - location of connecting grid block(s)


4 K - location of upper connecting block in this set of data

• DEFAULT: (corresponds to top connection of well)

5 K - location of lower connecting block in this set of data

• DEFAULT: (corresponds to bottom connection of well)

The following economic limits will be applied to all the connections in the well that match the location indices specified in items 2 - 5. But if a location index is defaulted to zero, it plays no part in selecting which connections have these limits. Thus if the I and J location indices are defaulted to zero, the economic limits are applied to all connections in the well that are located between layers K1 and K2 specified in items 4 and 5. If all four location indices are defaulted, the limits are applied to all the connections in the well.

6 Maximum water cut (water-liquid ratio)

• UNITS: sm3/sm3 (METRIC), stb/stb (FIELD),

• DEFAULT: No limit

7 Maximum gas-oil ratio

• UNITS: sm3/sm3 (METRIC), Mscf/stb (FIELD),


8 Maximum water-gas ratio

A value of 0.0 switches off this limit

• UNITS: sm3/sm3 (METRIC), stb/Mscf (FIELD),


9 Workover procedure when a limit is violated


SPECIALx FRONTSIM

RUNSPECGRIDEDITPROPSREGIONSSOLUTIONSUMMARY

x SCHEDULE

FrontSim User Guide KeywordsCECON

99

CON Shut the connection

+CON Shut the connection and all below it (see keyword COMPORD)

• DEFAULT: CONRequired but not used by FrontSim

10 1*

11 Minimum oil production rate

If its oil production rate falls below this value, the connection is shut (and all below it, if item 9 requests).

• UNITS: sm3/day (METRIC), stb/day (FIELD),

• DEFAULT: 0.0

12 Minimum gas production rate

If its gas production rate falls below this value, the connection is shut (and all below it, if item 9 requests).

• UNITS: sm3/day (METRIC), Mscf/day (FIELD),

• DEFAULT: 0.0


13 1*

Notes1 If keyword COMPLUMP is used to lump connections into completions, the connection

economic limits are applied to whole completions (that is a whole completion is closed if its total water cut, GOR or WGR exceeds the limit set for its connections, or if its total oil or gas production rate falls below the minimum value set for its connections). All connections in the same completion must be given the same limits.

Example

CECONPROD1 4* 0.7 / Water cut limit for all connections in well 'P*' 2* 2 2 1* 3.5 / GOR limit for layer-2 connections

/ in all wells with names beginning with P

100 Keywords FrontSim User GuideCECONINJ

CECONINJ Economic limits for injection well connectionsCECONINJ is used to set economic limits for injection well connections. If an individual connection violates one of its economic limits it will be automatically closed. The well connections must already be defined before this keyword can be used.

CECONINJ is followed by any number of records, described below, each record terminated by a slash (/). A record may be terminated early at any item; the remaining items assume their default values. Default values can be specified before the slash by a null repeat count of the form n*, where n is the number of consecutive items to be defaulted.


Each record can contain up to 9 items:








• DEFAULT: (corresponds to top connection of well)


• DEFAULT: (corresponds to bottom connection of well)

6 Minimum economic injection rate for connection or completion (COMPLUMP)

• UNITS OIL/WATER: sm3 /day (METRIC), stb/day (FIELD)

• UNITS GAS: sm3 /day (METRIC), Mscf/day (FIELD) - GAS

• DEFAULT: 0.0

7 Workover procedure when a limit is violated

CON Shut the connection

+CON Shut the connection and all below it (see keyword COMPORD)

WELL Shut the well

• DEFAULT: CON

8 Minimum economic oil cut for completion pattern

• UNITS: sm3/sm3 (METRIC), stb/stb (FIELD)

• DEFAULT: 0.0

9 Minimum economic remaining recoverable oil as a fraction of 'possible' bundle HC pore volume.

'Possible' implies HC that could be contained in the given bundle pore volume.

ECLIPSE 100ECLIPSE 300SPECIAL

x FRONTSIMRUNSPECGRIDEDITPROPSREGIONSSOLUTIONSUMMARY

x SCHEDULE

FrontSim User Guide KeywordsCECONINJ

101

Fraction = CPMOIPL / (CPMOIPL+CPOPTL)

• UNITS: fraction

• DEFAULT: 0.

10 Minimum economic bundle oil production rate

• UNITS: sm3/day (METRIC), stb/day (FIELD)

• DEFAULT: 0.

Notes

1 Usage of COMPLUMP is REQUIRED to lump connections into completions if limits are set on bundle type properties (items #8 - #10)

Example

CECONINJ*LIST1 0 0 1 2 10.0 1* 0.9 1 100.0 //

102 Keywords FrontSim User GuideCNAMES

CNAMES Component namesIn a run with components, this keyword associates an identifying character string with each component for reporting purposes. These may be of up to eight characters.

The keyword should be followed by values. These may be enclosed in quotes, although these are only required when blank characters are used, or the name starts with a non-alphabetical character.

Example


SPECIALx FRONTSIM

RUNSPECGRIDEDIT


CNAMESMeth Ethane C3-C6 C7+ /

Nc

Nc

FrontSim User Guide KeywordsCOMPDAT

103

COMPDAT Well completion specification dataCOMPDAT specifies the position and properties of one or more well completions. This must be entered after the WELSPECS keyword defining the appropriate well.

FrontSim only The well is without completions, that is inactive, until a COMPDAT record is encountered in the SCHEDULE section. However, if none are specified at all, a default COMPDAT with all layers active is implied.

The keyword is followed by any number of records, described below, each record terminated by a slash (/). A record may be terminated at any item after item 9; the remaining items assume their default values. If the well bore diameter is not required (see item 9), the record can be terminated after item 8.

A single record can be used to assign the properties of several connections of a well, as long as they are situated in the same vertical column of grid blocks. A deviated well can be completed in more than one column, but each column requires a separate record.

The set of records must end with a blank record, containing only a slash (/).Default values can be specified before the slash by a null repeat count of the form n*, where n is the number of consecutive items to be defaulted.

1 An asterisk (*) can be used to refer to multiple wells. Well list names should begin with an asterisk (*). Well lists are constructed with the keyword WLIST.


If set to 0 or defaulted, the I - location of the well head (entered in keyword WELSPECS) will be used.


If set to 0 or defaulted, the J - location of the well head (entered in keyword WELSPECS) will be used.



The following data then applies to each layer (or connection) with K - locations between the upper and lower values given above.

6 Open/shut flag of connection

OPEN Connection open to flow

SHUT Connection closed off

• DEFAULT: OPENRequired but not used by FrontSim

7 1*

8 Transmissibility factor for the connection


SPECIALx FRONTSIM


x SCHEDULE

104 Keywords FrontSim User GuideCOMPDAT

If defaulted, the connection transmissibility factor is calculated using the remaining items of data in this record. The well bore diameter must be set in item 9.

• UNITS: cP-m3/day-bars, (METRIC), cP-rb/day-psi (FIELD),

Note If a connection factor is smaller than 0.00001 - it is automatically closed by FrontSim

9 Well bore diameter at the connection

This quantity is required for:

Calculating the connection transmissibility factor.


• DEFAULT: 0.25 m = 0.82 ft

10 Effective Kh (permeability x thickness) value of the connection

If a default is entered, the Kh value is calculated from the grid block data.

• UNITS: mD-m (METRIC), mD-ft (FIELD),

• DEFAULT: Calculated by FrontSim

11 Skin factor

This quantity is used for the same purposes as listed for item 9. It is ignored if not required.

Large negative skin factors can cause problems if they increase the effective wellbore radius to approach the pressure equivalent radius of the grid block. Very high values of the connection transmissibility factor may result, which could cause convergence problems. In these circumstances, it may be preferable to change the grid block data near the well to model the physical cause of the negative skin (for example enhance the permeability out to a certain distance from the well). If the effective wellbore radius is increased beyond the pressure equivalent radius, the connection factor becomes negative and an error message is issued.

• DEFAULT: 0.0Required but not used by FrontSim

12 1*

13 Direction in which the well penetrates the grid block

X the well penetrates the grid block in the X direction

Y the well penetrates the grid block in the Y direction

Z the well penetrates the grid block in the Z direction

• DEFAULT: Z

This item is used in calculating the transmissibility factor of the connection if it was not supplied in item 8. In Cartesian grids the Peaceman formula is used, taking the components of permeability and grid block dimensions appropriate to the direction of penetration. Note that the formula assumes that the well completely penetrates a rectangular block through its centre in a direction perpendicular to two of its faces.


14 1*

FrontSim User Guide KeywordsCOMPDAT

105

Example

COMPDATPROD1 6 8 1 3 1* 1* 0.0 0.333 500 3.5 1* Z /

106 Keywords FrontSim User GuideCOMPDATL

COMPDATL Completion data for wells in local gridsCOMPDATL must be used in place of COMPDAT to specify the connection data for wells in local refined grids, after the wells have been introduced with keyword WELSPECL.

Note The keyword data for COMPDATL is the same as for COMPDAT, except for an extra item (item 2) that names the local grid containing the connections specified in the record.

Example



x SCHEDULE

COMPDATLPROD1 CARF1 6 4 1 3 OPEN 0 0.0 0.333 500 3.5 1E-3 Z /PROD2 CARF2 3 5 3 3 OPEN 3 0.0 0.333 /PROD3 CARF3 3 5 2 2 OPEN 0 1* 0.333 3* X /PROD3 CARF3 4 5 2 3 OPEN 0 1* 0.333 3* X //

FrontSim User Guide KeywordsCOMPLUMP

107

COMPLUMP Lumps connections into completionsNote COMPLUMP is used to lump connections together into completions for simultaneous

closure in automatic workovers. In FrontSim COMPLUMP is ONLY available for use with CECON and CECONINJ keywords and for completion based summary vector reporting.

The connections must first have been defined with the keyword COMPDAT.

When a connection is first defined with keyword COMPDAT, it is given a completion number equal to its order of introduction in the well. For example, the third connection defined in the well is put in completion number three. When several connections are defined in one record (items 4 and 5 define the upper and lower layers), the connections are introduced in layer order from top to bottom. So if the keyword COMPLUMP is not used, each connection is in its own separate completion, and the terms completion and connection are equivalent.

COMPLUMP is followed by any number of records, described below, each record terminated by a slash (/). The set of records must end with a blank record, containing only a slash.

Each record contains 6 items:






• DEFAULT: 0 (allows any J-value)

4 K - location of upper connecting block in this completion

• DEFAULT: 0

5 K - location of lower connecting block in this completion

• DEFAULT: 0

6 Completion number of the connections

The set of connections in the well which match the location indices specified in items 2- 5 will be given the completion number specified in item 6. All connections having the same completion number are treated as belonging to the same completion, and will be closed together in an automatic workover. If a location index is defaulted to zero, it plays no part in selecting the set of connections. Thus if the I and J location indices are defaulted to zero, all connections in the well that are located between layers K1 and K2 specified in items 4 and 5 will be given the completion number specified in item 6. If all four location indices are defaulted, all the well’s connections will be given this completion number.


SPECIALx FRONTSIM


x SCHEDULE

108 Keywords FrontSim User GuideCOMPLUMP

ExampleCOMPLUMP

PROD1 2* 1 2 1 / connections in layers 1 and 2 are in completion 1PROD1 2* 3 4 2 / connections in layers 3 and 4 are in completion 2PROD1 2* 5 5 3 / the connection in layer 5 is in completion 3

/

FrontSim User Guide KeywordsCOMPORD

109

COMPORD Defines the ordering of well connectionsThe keyword is followed by any number of records, each containing the following items of data, and each terminated with a slash (/).


1 Well name or well name root

A well name root, enclosed in quotes and ending with an asterisk (*), can be used to refer to several wells in one record.

2 Method for ordering the connections in the well

DEPTH The connections will be ordered according to their vertical depth, from the top downwards. For connections at the same vertical depth, they will be ordered in the sequence they are first declared in COMPDAT or COMPDATL.

INPUT The connections will be ordered in the sequence that they are first declared in COMPDAT or COMPDATL. If you use this option, you must declare the connections in their correct sequence, starting with the connection nearest the wellhead then working along the wellbore towards the bottom or toe of the well.

TRACK FrontSim will determine the order of the connections by attempting to trace the well track through the grid from the grid blocks in which the connections are located. If this fails, or if all the connections in the well are vertical (according to COMPDAT item 13 or COMPDATL item 14), DEPTH ordering will be used. See Note 2 for further explanation.

• DEFAULT: TRACK

End the data record with a slash (/).

End the set of records with a blank record, containing just a slash.

Notes1 FrontSim uses the connection ordering when calculating the wellbore hydrostatic head with

the Segmented density calculation (WELSPECS item 12 set to SEG). The connection ordering also determines which additional connections are closed in a +CON workover (see for example WECON item 7). In these workovers, all connections below the offending one are also closed. Here, “below” is interpreted as “further from the wellhead according to the connection ordering”.

2 When the TRACK method is selected, FrontSim determines the connection ordering as described below. If all connections in the well penetrate vertically (Z-direction in COMPDAT item 13 or COMPDATL item 14), the connections are ordered according to their depth. But if any connection is declared to be horizontal (X- or Y-direction), FrontSim will attempt to order the connections in heel-to-toe fashion. It takes the heel to be the connection whose I,J coordinates are nearest the wellhead I,J (set in WELSPECS items 3 and 4, or WELSPECL items 4 and 5). If more than one connection can be a candidate for the heel, FrontSim selects the one with the minimum depth. The rest of the ordering is determined from the location and orientation of the connections.

3 The COMPORD keyword is optional. If it is not entered, all wells will use the TRACK method.


SPECIALx FRONTSIM


x SCHEDULE

110 Keywords FrontSim User GuideCOMPORD

Example

COMPORDHWELL1 INPUT /HWELL2 INPUT //

FrontSim User Guide KeywordsCOMPS

111

COMPS Requests compositional modeThis keyword activates the compositional mode. COMPS takes one argument, the number of components to be used in the simulation. In the documentation, the argument of the COMPS keyword is referred to as .

Example


SPECIALx FRONTSIMx RUNSPEC

GRIDEDITPROPSREGIONSSOLUTIONSUMMARYSCHEDULE

COMPS12 /

Nc

112 Keywords FrontSim User GuideCOORD

COORD Coordinate linesThe presence of the COORD keyword implies corner point geometry and the automatic generation of fault transmissibilities.

A coordinate line defines the possible positions for grid block corner points, for each (i,j) cell and for each reservoir in the grid. Given the depth of a particular grid block corner, and the associated coordinate line, the X and Y coordinates of the corner point can be calculated.

A coordinate line is specified by two triplets of X, Y and Z coordinates, representing two distinct points on it. If the (X, Y) coordinates of the top and bottom points are identical, then the Z coordinates of the points are not used.

The amount of data for this keyword can be quite voluminous, so it is recommended that a pre-processor (such as GRID or FloGrid) be used to construct it.

This keyword may not be used with block-centered geometry keywords, namely DXV, DYV, DZV.

The keyword line is followed by coordinate lines, each specified by two points, each consisting of 3 values, namely, the X, Y and Z coordinates.

The last coordinate line is followed by a slash (/).


ExampleHere NDIVIX = 3, NDIVIY = 2, NDIVIZ = 10:


SPECIALx FRONTSIM

RUNSPECx GRID


COORD0 0 1000 0 0 10001000 0 1000 1000 0 10002000 0 1000 2000 0 10003000 0 1000 3000 0 10000 2000 1000 0 2000 10001000 2000 1000 1000 2000 10002000 2000 1000 2000 2000 10003000 2000 1000 3000 2000 10000 4000 1000 0 4000 10001000 4000 1000 1000 4000 10002000 4000 1000 2000 4000 10003000 4000 1000 3000 4000 1000/

NDIVIX 1+( ) NDIVIY 1+( )

FrontSim User Guide KeywordsCOORDXYZ

113

COORDXYZ X, Y, Z coordinates of the gridThe COORDX, COORDY and COORDZ keywords describe the x, y, z coordinates of the grid nodes. The number of values given must be equal to the number of nodes in the grid.

ExampleHere NDIVIX = 3, NDIVIY = 2 and NDIVZ=1.


x FRONTSIMRUNSPEC

x GRIDEDITPROPSREGIONSSOLUTIONSUMMARYSCHEDULE COORDX

1. 4. 6. 9.1. 4. 6.5 9.1. 4. 5.2 8.

1. 4. 6. 9.1. 4. 6.5 9.1. 4. 5.2 8./COORDY1. 1. 0.0 1.23. 3. 1.5 3.5. 6.0 5.6 4.5

1. 1. 0.0 1.23. 3. 1.5 3.5. 6.0 5.6 4.5/COORDZ100 100 100 100100 100 100 100100 100 100 100

200 200 200 200200 200 200 200200 200 200 200/

114 Keywords FrontSim User GuideCOPY

COPY Copies data from one array to anotherThis keyword is used to assign or replace the value of a property for a box of cells within the grid, using the value of another property.

The keyword may be followed by any number of records, each of which is terminated by a slash (/). The data is terminated by a null record (that is, a record with no data before the terminating slash(/)).


1 From array.

The name of the array to be used from which data is to be copied

2 To array.

The name of the array to be set. Only this array is altered.

Items 3-8 may be used to re-define the input box for this and subsequent operations within the current keyword.










1 ≤ IX1 ≤ IX2 ≤ NDX

1 ≤ JY1 ≤ JY2 ≤ NDY

1 ≤ KZ1 ≤ KZ2 ≤ NDZ,


Any array defined across the grid may be used with COPY.

Examples

Example 1Set PERMY to PERMX:


SPECIALx FRONTSIM



COPYPERMX PERMY //

FrontSim User Guide KeywordsCOPY

115

Example 2In the GRID section:

In the REGIONS section:

-------- SOURCE DESTINATION ----- BOX -----COPY

PERMX PERMY 1 11 1 19 1 4 /PERMX PERMZ / defaults to last specified box

/-------- ARRAY FACTORMULTIPLY

PERMZ 0.1 //

COPYSATNUM FIPNUM //

116 Keywords FrontSim User GuideDATES

DDATES Advances simulator to specified report

date(s)The keyword should be followed by a list of dates at which reports are required. Each date must be on a separate line terminated by a slash (/). The data is terminated by a null record (a slash on a line by itself).

A date consists of three items of data:

1 The day of the month

(An integer between 1 and 31)

2 The name of the month abbreviated to three characters.

(JAN, FEB, MAR, APR, MAY, JUN, JLY, AUG, SEP, OCT, NOV or DEC). JUL is an acceptable alternative to JLY.

3 The year

(A positive 4 digit integer).

4 The time

A string of the format HH:MM:SS.SSSS.

• DEFAULT: 00:00:00

Note The date at the start of the simulation (time 0) is entered using the keyword START in the RUNSPEC section.

Example


SPECIALx FRONTSIM


x SCHEDULE

DATES1 FEB 1985 /1 MAR 1985 06:00:00 /1 MAY 1985 13:30:00 /1 JAN 1986 /1 JAN 1987 19:45:15.3333 //

FrontSim User Guide KeywordsDATUM

117

DATUM Datum depth for output of depth corrected pressuresThe keyword should be followed by a single positive real number, the datum depth for calculation of depth corrected pressures, and a slash (/). DATUM is entirely optional. If it is not specified, and output of depth corrected pressures is requested, it defaults to the datum depth entered for equilibration region 1 using the EQUIL keyword, or to zero if there is no EQUIL keyword.


Example


SPECIALx FRONTSIM



DATUM4800 /

118 Keywords FrontSim User GuideDENSITY

DENSITY Fluid densities at surface conditionsThe data comprises three fluid densities for each pressure table region. The number of pressure table regions is given by the FIPNUM keyword in the REGIONS section and defaults to 1. Each record consists of 3 items of data, and is terminated by a slash (/).

1 The density of oil at surface conditions.

• UNITS: METRIC: kg/m3, FIELD: lb/ft3

2 The density of water at surface conditions.


3 The density of gas at surface conditions.


ExampleFor a black oil case, all three phase densities are specified:


SPECIALx FRONTSIM

RUNSPECGRIDEDIT


DENSITY45.0000 63.0200 .07020 /

FrontSim User Guide KeywordsDEPTHZ

119

DEPTHZ Depth to all top layer nodesDefines depth to (NDIVIX+1)*(NDIVIY+1) top grid nodes.

This keyword must be followed by THICKZ or DZV (requires flat top layer values).


ExampleNDIVIX = 4, NDIVIY = 3 and NDIVZ=2.


x FRONTSIMRUNSPEC

x GRIDEDITPROPSREGIONSSOLUTIONSUMMARYSCHEDULE

DEPTHZ20*2000.0 /

THICKZ20*5.020*4.0/

120 Keywords FrontSim User GuideDIMENS

DIMENS Specifies the dimensions of the gridThis keyword defines the basic size of the simulation grid. It is followed by three integers, specifying the number of cells in the x, y and z directions respectively. In the documentation, the arguments of the DIMENS keyword are frequently be referred to as , and , or NDIVIX, NDIVIY and NDIVIZ.

There is no default. It is an error not to supply the grid dimensions.

ExampleFor a reservoir represented by a 10 x 3 x 4 grid the keyword would be:




DIMENS10 3 4 /

Nx Ny Nz

FrontSim User Guide KeywordsDPGRID

121

DPGRID Use matrix cell grid data for fracture cellsThis keyword may be used to simplify the input of data for dual porosity runs. It enables grid data to be entered for the matrix cells only (the first NDIVIZ/2 layers), the missing values for the remaining fracture layers being obtained from the corresponding matrix cell.

This operation will be performed for the PERMX, PERMY, PERMZ, PORO, NTG, ZCORN, PERMXY, PERMYZ and PERMZX keywords. The copying of the matrix cell value into the fracture cell value will only occur if the fracture cell value has not been defined by the user.

In the case of the ZCORN keyword, only half the normal set of corner point depths need be supplied (and generated by Petrel or FloGrid). This is useful when preparing faulted dual porosity runs. As in the case of the other keywords, the BOX keyword may be used to specify values for the cells required.


SPECIALx FRONTSIM

RUNSPECx GRID


122 Keywords FrontSim User GuideDRSDT

DRSDT Maximum rate of increase of solution GORThis keyword controls the rate at which the solution gas-oil ratio is allowed to rise. The keyword should be followed by two items of data terminated by a slash (/):

Item 1: DRSDT

Represents the maximum rate at which the solution gas-oil ratio in any grid block (Rs) is allowed to increase.

• UNITS: sm3/sm3/day (METRIC), Mscf/stb/day (FIELD)

Item 2: Option flag

'ALL': Apply the DRSDT limit to all cells

'FREE': Apply the DRSDT limit only to cells containing free gas. Beware that this option is not available in FrontSim

• DEFAULT: 'ALL'

This keyword controls the way in which free gas and undersaturated oil coexist within a grid block. For example, if DRSDT is set to 0, Rs cannot rise and free gas does not dissolve in undersaturated oil (no re-solution). At the other extreme, if DRSDT is very large, Rs rises very quickly until either the oil is saturated or no free gas remains (total re-solution).

If the keyword is not used, the re-solution rate is unrestricted (equivalent to a re-solution rate limit of infinity).

Note This keyword has no effect on reductions in Rs (for example during pressure decline). Moreover, increases in Rs are constrained by the availability of free gas and the oil saturation limit (Rssat).

This keyword has no effect in any system containing both dissolved gas and vaporized oil.

If DRSDT = 0 and the model contains undersaturated oil with a variation of Rs values, then non-physical behavior can occur when high Rs oil moves in to a cell containing a lower Rs. The DRSDT limit prevents the Rs increasing, and free gas develops, even though the oil is undersaturated.

Example

x ECLIPSE 100ECLIPSE 300SPECIAL


x SCHEDULE

DRSDT0.0003 / (in Mscf/stb/day)

FrontSim User Guide KeywordsDPNUM

123

DPNUM Identifies extent of dual porosity regionThe DPNUM keyword may be used for a dual porosity, single permeability run to specify regions within the reservoir to be treated as single porosity only.

The keyword should be followed by the integer 0 or 1 for each grid block in the first NDIVIZ/2 layers, to indicate whether the grid block should be modeled as single porosity (0) or dual porosity (1). Any grid blocks that do not have a DPNUM value entered default to dual porosity (1).


The keyword is ignored unless dual porosity, single permeability is enabled in the RUNSPEC section using keyword DUALPORO.

Note Grid data for single porosity cells is only required in the first NDIVIZ/2 layers. That is the grid block properties are only required for the matrix cells. Since for Dual Porosity models in FrontSim the streamline tracing is only done in the fracture cells, FrontSim will copy the contents of the matrix cell into the fracture cell and then remove the matrix cell. This behavior is different to ECLIPSE 100 and ECLIPSE 300 where the fracture cell is removed. The user needs to be aware of this whenever completions and aquifer contacts are input; any such contacts in the matrix will be ignored by FrontSim.

ExampleTo specify an 8x4x4 run as dual porosity in half of the reservoir, specify DUALPORO in RUNSPEC, and add the following in the GRID section:


SPECIALRUNSPEC


DPNUM4*0 4*1 4*0 4*14*0 4*1 4*0 4*14*0 4*1 4*0 4*14*0 4*1 4*0 4*1 /

124 Keywords FrontSim User GuideDRVDT

DRVDT Maximum rate of increase of vapor OGRThe keyword should be followed by a single real number which represents the maximum rate at which the vapor oil-gas ratio in any grid block (Rv) is allowed to increase. The data field should be terminated by a slash (/).

This keyword controls the way in which free oil and undersaturated gas coexist within a grid block. For example, if DRVDT is set to 0, Rv cannot rise and free oil does not vaporize in undersaturated gas (no re-vaporization). At the other extreme, if DRVDT is very large, Rv rises very quickly until either the gas is saturated or no free oil remains (total re-vaporisation).

If the keyword is not used, the re-vaporization rate is unrestricted (equivalent to a re-vaporization rate limit of infinity).

Note This keyword has no effect on reductions in Rv.Moreover increases in Rv are constrained by the availability of free oil and the gas saturation limit (Rvsat).

This keyword has no effect in any system containing both dissolved gas and vaporized oil.

• UNITS: sm3/sm3/day (METRIC), Mscf/stb/day (FIELD).

Example



x SCHEDULE

DRVDT0.009 /

FrontSim User Guide KeywordsDUALPORO

125

DUALPORO Run is to use dual porosityThis requests that the dual porosity option is used in the run.

If DUALPORO is used, the number of layers entered in item 3 of the DIMENS keyword must be even. FrontSim interprets the first half of the grid layers as matrix cells, and the remainder as fracture cells. The non-neighbor connections representing matrix-fracture flow transmissibilities are automatically constructed.

See "Dual Porosity" in the "FrontSim Technical Description" for further information.

The keyword has no associated data.




126 Keywords FrontSim User GuideDUMPFLUX

DUMPFLUX Makes a full-field run write a flux fileThe DUMPFLUX keyword is used in the full-field run to tell FrontSim to write a FLUX file containing the flows across the flux region boundaries.

The extent of the flux regions are defined by the FLUXNUM keyword.


Note The flows are derived by multiplying the average flow of all phases by the relative mobility of each phase. This means that in situations where the effect of gravity is important the boundary conditions may be different from those obtained using ECLIPSE Blackoil to generate the FLUX file. This is most likely to affect 3-phase models where there are vertical flows out of the Flux Region.


SPECIALx FRONTSIM

RUNSPECx GRID


FrontSim User Guide KeywordsDXV/DYV

127

DXV/DYV Grid block sizes in X/Y direction (vector)These keywords specify the size of the cells in the X or Y-direction.

DXV should be followed by NDIVIX positive real numbers, where NDIVIX is the grid X dimension entered using the DIMENS keyword in the RUNSPEC section.

DYV should be followed by NDIVIY positive real numbers, where NDIVIY is the grid Y dimension entered using the DIMENS keyword in the RUNSPEC section.

Repeat counts may be used for repeated values (for example 11*208.4). Note that spaces may not be inserted on either side of the asterisk.


The data must be terminated by a slash (/).

ExampleWith NDIVIX = 11, NDIVIY = 5:


SPECIALx FRONTSIM

RUNSPECx GRID


DXV1000 500 7*200 500 1000 /DYV1000 500 200 500 1000 /

128 Keywords FrontSim User GuideDZV

DZV Z-direction grid block sizes (vector)This keyword specifies the size of the cells in the Z-direction.

The keyword should be followed by NDIVIZ positive real numbers, where NDIVIZ is the grid Z dimension entered using the DIMENS keyword in the RUNSPEC section.

DZV should be used with DEPTHZ (with flat values), which sets a top depth different from 0 (default).



ExampleNDIVIX = 4, NDIVIY = 3 and NDIVZ=2


SPECIALx FRONTSIM

RUNSPECx GRID


DEPTHZ20*2000 /

DZV10 5 /

FrontSim User Guide KeywordsEDITNNC

129

EEDITNNC Change a non-neighbor connection

Non-neighbor connections may be generated by geological faults in the grid. This keyword can be used to modify these fault generated non-neighbor connections.

The form of the keyword is as follows:

Each line following the EDITNNC keyword specifies a non-neighbor connection to be modified and is terminated with a slash (/). After the last non-neighbor modification, a single (/) terminates the list.

The arguments in each line are:

1 I-index of first cell joined to the non-neighbor connection (IX)

2 J-index of first cell joined to the non-neighbor connection (IY)

3 K-index of first cell joined to the non-neighbor connection (IZ)

4 I-index of second cell joined to the non-neighbor connection (JX)

5 J-index of second cell joined to the non-neighbor connection (JY)

6 K-index of second cell joined to the non-neighbor connection (JZ)

The cell coordinates must be defined and cannot be defaulted

7 Transmissibility multiplier for the non-neighbor connection (TRANM)

The transmissibility is set to TR*TRANM, where TR is the non-neighbor connection transmissibility calculated by the program or entered directly through the NNC keyword.

The multiplier TRANM should not be negative but can be zero.

• DEFAULT: 1.0

If a non-neighbor connection to be edited cannot be found, then a warning message is issued and the EDITNNC line is ignored.

Note A list of the non-neighbor connections generated by FrontSim that can be edited using EDITNNC may be obtained by setting OPTIONFS item 16 to 1.


SPECIALx FRONTSIM

RUNSPECGRID

x EDITPROPSREGIONSSOLUTIONSUMMARYSCHEDULE

EDITNNCIX IY IZ JX JY JZ TRANM /../

130 Keywords FrontSim User GuideEND

END Logical end of input fileThis keyword terminates the input of data in the SCHEDULE section (FrontSim).

The END keyword need not be the actual end of the input file. However, if no END keyword is provided one is generated at the end of the input data file.

END has no arguments.


SPECIALx FRONTSIMx RUNSPECx GRIDx EDITx PROPSx REGIONSx SOLUTIONx SUMMARYx SCHEDULE

FrontSim User Guide KeywordsENDBOX

131

ENDBOX Reset current input box to encompass the entire grid The ENDBOX keyword has no associated data.

It causes the input box to be reset so that it encompasses the entire grid.

Note that at the end of each input section (GRID, EDIT, PROPS etc.), the program effectively supplies an ENDBOX, and resets the input box.

See also keywords BOX, ADD, COPY, EQUALS, MULTIPLY.

ExampleThus, for an 11 by 19 by 4 grid, it has the same effect as:


SPECIALx FRONTSIM


SUMMARYx SCHEDULE

BOX1 11 1 19 1 4 /

132 Keywords FrontSim User GuideENDFIN

ENDFIN Terminates data for a local grid refinementIn the GRID section, the ENDFIN keyword tells the program to finish reading GRID data for the local grid named in the previous CARFIN keyword. Any subsequent GRID section keywords are taken to apply to the global grid, until another local grid is specified by CARFIN.

It is not necessary to insert ENDFIN between successive CARFIN keywords. The primary purpose of ENDFIN is to revert the program to reading data for the global grid system.

In the EDIT, PROPS, REGIONS, SOLUTION and SCHEDULE sections, the ENDFIN keyword tells the program that subsequent data no longer applies to the local grid named in the previous keyword.

The ENDFIN keyword has no associated data.

ExampleIn the GRID section:



SUMMARYx SCHEDULE

CARFIN-- NAME I1-I2 J1-J2 K1-K2 NX NY NZ NWMAX--

LGR1 2 2 3 3 3 4 5 5 8 5 /PORO200*0.2 /EQUALS

PERMX 500 /PERMY 500 /PERMZ 50 /

/ENDFIN

FrontSim User Guide KeywordsENDINC

133

ENDINC Logical end of include fileThe ENDINC keyword terminates the input of data from an INCLUDE file, returning control to the reading of the main file.

This keyword should not normally be entered, as an ENDINC is generated automatically at the end of the included file. It may, however, be used to end the reading of an included file before the actual end of file.



134 Keywords FrontSim User GuideENDNUM

ENDNUM End point scaling versus depth region numbersThe keyword should be followed by one integer for every grid block in the current input box, specifying the end point scaling versus depth table region to which it belongs. The region number should not be less than 1 or greater than the number of table entries in keyword ENPTVD. The data must be terminated by a slash (/).

The region number specifies which end point scaling versus depth table (input using ENPTVD) should be used to calculate the saturation table end points for each grid block. The end point scaling option should be activated by specifying keyword ENDSCALE in RUNSPEC.


Examples

Example 1With NTENDP=4, NDIVIX=8, NDIVIY=6, NDIVIZ=5 and no input BOX set:

Example 2• A 12x4x5 grid

• Layers 1, 2, 3 assigned to end point scaling region number 1

• Layers 4, 5 assigned to end point scaling region number 2


SPECIALx FRONTSIM

RUNSPECGRIDEDITPROPS

x REGIONSSOLUTIONSUMMARYSCHEDULE

ENDNUM8*1 16*2 8*3 16*48*1 16*2 8*3 16*48*1 16*2 8*3 16*48*1 16*2 8*3 16*48*1 16*2 8*3 16*4 /

ENDNUM144*1 96*2 /

FrontSim User Guide KeywordsENDSCALE

135

ENDSCALE Use saturation table end-point scalingThis indicates that the saturation table End-point Scaling option is to be used. It is often convenient to scale the endpoints of the relative permeability curves for each cell. This option is enabled by the ENDSCALE keyword. Table end-points can then be entered by cell (keywords such as SWL, SWCR and SWU) or with respect to depth (ENPTVD).

For compatibility with ECLIPSE, the keyword may be followed by up to four items, indicating that the end-point scaling is non-directional and reversible, and setting the dimensions of the end-point scaling tables.

FrontSim does not require these data items, and does not support directional or irreversible end-point scaling.

The data should be terminated by a slash (/).

1 Directional end-point scaling switch

NODIR The saturation table end-point scaling is not directional. The same saturation table is used for flow in the X, Y or Z directions.

• DEFAULT: NODIR

2 Irreversible end-point scaling switch

REVERS The end-point scaling is reversible. The same table is used whether the flow is from I to I+1 or from I to I-1.

• DEFAULT: REVERSNot required for FrontSim 3 The maximum number of saturation end-point versus depth tables (see keyword ENPTVD

in the PROPS section).

• DEFAULT: 1

Not required for FrontSim 4 The maximum number of nodes in any saturation end-point versus depth table (see keyword ENPTVD in the PROPS section).

• DEFAULT: 20

ExampleEnd-point scaling is not directional and is reversible.




ENDSCALENODIR REVERS /

136 Keywords FrontSim User GuideENKRVD

ENKRVD Relative permeability end point versus depth tablesThe different forms of this keyword allow the user to specify the depth variation of the maximum relative permeability for the three phases. These keywords complement the ENPTVD keyword, which specifies how the end point saturation values vary with depth.

The keyword ENDSCALE in the RUNSPEC section should also be specified.

The data comprises NTENDP (item 3 of keyword ENDSCALE) tables of relative permeability end points vs. depth, one for each end point scaling region. Each table consists of 8 columns of data, and must be terminated by a slash (/).

Column 1: Depth values.

The values should increase monotonically down the column.


Column 2: The corresponding values of the maximum water relative permeability.

Column 3: The corresponding values of the maximum gas relative permeability.

Column4: The corresponding values of the maximum oil relative permeability.

Column 5: Water relative permeability at the critical oil (or gas) saturation.

Column 6: Gas relative permeability at the critical oil (or water) saturation.

Column 7: Oil relative permeability at the critical gas saturation.

Column 8: Oil relative permeability at the critical water saturation.

There must be the same number of entries in each column of a given table. This number should not be less than 2 or greater than NSENDP (item 4 of keyword ENDSCALE). If an end point is defaulted for all depth values, in a problem where a value could correctly be defined, then the end point for each cell in the same scaling region will be the value in the appropriate saturation function table. However if an end point is defaulted at a certain depth but has been defined at other depths, the end point vs. depth table will be ‘filled in’ by linear interpolation within the table and constant extrapolation at the ends of the table. End point values entered for absent phases are ignored.

See also keyword ENDNUM in the REGIONS section, and the keyword ENPTVD in the PROPS section.


SPECIALx FRONTSIM

RUNSPECGRIDEDIT


FrontSim User Guide KeywordsENKRVD

137

Examples

Example 1

---- RUNSPEC sectionOILWATERGASENDSCALE-- NTENDP NSENDP

2* 1 3 /---- PROPS sectionENKRVD---- water gas oil water gas oil oil-- Depth Krw Krg Kro at crit at crit at crit at crit-- oil to oil to gas water-- water gas--

3000.0 0.50 1.0 1.0 0.3 1* 1* 0.346000.0 0.58 1.0 1.0 1* 1* 1* 0.369000.0 0.66 0.95 0.95 0.35 1* 1* 0.37/

138 Keywords FrontSim User GuideENPTVD

ENPTVD Saturation end point versus depth tablesThis keyword specifies the depth variation of the saturation table end points for different end point scaling regions within the reservoir. The flow of each phase across each grid block face is calculated using transformed relative permeability curves obtained by linearly scaling the tabulated curves between the end points specified using the ENPTVD keyword. The ENPTVD keyword also permits scaling of the relative permeability tables used in computing the flow of phases between grid cells and well connections and scaling in the equilibration algorithm.

The keyword ENDSCALE should be specified in the RUNSPEC section.

The data comprises tables of saturation end points vs. depth, one for each end point scaling region. Each table consists of 9 columns of data, and must be terminated by a slash (/).




Column 2: The corresponding values of the connate water saturation.

Column 3: The corresponding values of the critical water saturation.

Column 4: The corresponding values of the maximum water saturation.

Column 5: The corresponding values of the connate gas saturation.

Column 6: The corresponding values of the critical gas saturation.

Column 7: The corresponding values of the maximum gas saturation.

Column 8: The corresponding values of the critical oil-in-water saturation.

Column 9: The corresponding values of the critical oil-in-gas saturation.

There must be the same number of entries in each column of a given table. This number should not be less than 2. Each saturation entry should be in the range 0.0 to 1.0 inclusive. If a saturation end point is defaulted for all depth values, in a problem where a value could correctly be defined, then the end point for each cell in the same scaling region will be the value in the appropriate saturation function table. However if a saturation end point is defaulted and the end point has been defined at other depths, the end point versus depth table will be filled in by linear interpolation within the table and constant extrapolation at the ends of the table. End point values entered for absent phases are ignored.

The ENPTVD keyword defines the new saturation end points for flow out of each grid cell face, for well connection relative permeabilities and for the equilibration algorithm.

See also keyword ENDNUM in the REGIONS section.


SPECIALx FRONTSIM

RUNSPECGRIDEDIT


FrontSim User Guide KeywordsENPTVD

139

Example

---- RUNSPEC sectionOILWATERGASENDSCALE---- PROPS sectionENPTVD3000.0 0.20 0.20 1.0 0.0 0.04 1.0 0.18 0.229000.0 0.22 0.22 1.0 0.0 0.04 1.0 0.18 0.22 /

140 Keywords FrontSim User GuideEOS

EOS Specify which equation of state is to be usedIf an equation of state is being used in the compositional mode, this keyword enables one of four possibilities to be chosen.

The keyword is followed by a single argument, the first letter of which is significant.

The possible options are:

PR Peng-Robinson

RK Redlich-Kwong

SRK Soave-Redlich-Kwong

ZJ Zudkevitch-Joffe-Redlich-Kwong

Details of the equations of state are discussed in "Equations of State" in the "FrontSim Technical Description".

A slight modification to the Peng-Robinson equation is available, by using the PRCORR keyword.

• DEFAULT: Peng-Robinson

Example



GRIDEDIT


EOSPR /

FrontSim User Guide KeywordsEPSDEBUG

141

EPSDEBUG Controls debug for end-point scaling optionThis keyword can be used to write out the scaled relative permeability curves for individual grid blocks when the End Point Scaling option is active (keyword ENDSCALE in the RUNSPEC section). The curves are output as tables to the Debug file, and may optionally be output in the form of a GRAF user file which can be read directly into the GRAF program.

The keyword should be followed by 7 integers and optionally a local grid name, terminated with a slash (/). The first 6 integers define the box of cells for which the debug output will be generated. The 7th integer controls the form of the debug output.

Item 1: IX1

First cell on X axis to be included in output

Item 2: IX2

Last cell on X axis to be included in output

Item 3: JY1

First cell on Y axis to be included in output

Item 4: JY2

Last cell on Y axis to be included in output

Item 5: KZ1

First cell on Z axis to be included in output

Item 6: KZ2

Last cell on Z axis to be included in output

The values must satisfy:

1 ≤ IX1 ≤ IX2 ≤ NDIVIX

1 ≤ JY1 ≤ JY2 ≤ NDIVIY

1 ≤ KZ1 ≤ KZ2 ≤ NDIVIZ

Item 7: Debug switch

0 - Output in tabular form

1 - Output as GRAF user data

• DEFAULT: ' '

Item 8: Grid name

' ': Output cells in global and all local grids

GLOBAL: Output cells in global grid only

'lgr - name': Output cells in the named local grid.

• DEFAULT: ' '

This item will be ignored if Local Grid Refinement is not used (see "Local Grid Refinement" in the "FrontSim Technical Description"). The output can be quite extensive, and hence only small numbers of cells should be output from large models.


SPECIALx FRONTSIM

RUNSPECGRIDEDIT


142 Keywords FrontSim User GuideEPSDEBUG

Example

EPSDEBUG-- IX1 IX2 IY1 IY2 IZ1 IZ2 SWITCH

4 4 5 5 1 3 0 /

FrontSim User Guide KeywordsEQLNUM

143

EQLNUM Equilibration region numbersThe keyword should be followed by one integer for every grid block in the current input box specifying the equilibration region to which it belongs. The region number should not be less than 1. All blocks with the same equilibration region number must also have the same PVT region number (see keyword PVTNUM). The data must be terminated by a slash (/).


See also the keywords EQUIL, RSVD, RVVD and PBVD in the SOLUTION section.

ExampleWith NTEQUL=6:


SPECIALx FRONTSIM



-------- IX1-IX2 JY1-JY2 KZ1-KZ2BOX

4 11 3 8 1 5 /EQLNUM8*1 8*2 8*3 8*4 8*5 8*68*1 8*2 8*3 8*4 8*5 8*68*1 8*2 8*3 8*4 8*5 8*68*1 8*2 8*3 8*4 8*5 8*68*1 8*2 8*3 8*4 8*5 8*6 /

144 Keywords FrontSim User GuideEQUALS

EQUALS Set array to a constant in current boxThis keyword is used to assign or replace the value of a property for a box of cells within the grid.




2 The constant to be assigned to the array specified by item 1

The constant should be positive, and must be an integer if the array contains integer region numbers (for example, FIPNUM). The constant may be real if the array contains real data (for example, TRANX).

Items 3-8 may be used to re-define the input box for this and subsequent operations within the current keyword.










1 ≤ IX1 ≤ IX2 ≤ NDX

1 ≤ JY1 ≤ JY2 ≤ NDY

1 ≤ KZ1 ≤ KZ2 ≤ NDZ,


See also keywords BOX, ENDBOX, ADD, MULTIPLY and COPY.


SPECIALx FRONTSIM



FrontSim User Guide KeywordsEQUALS

145

Examples



-------- ARRAY CONSTANT ----- BOX -----EQUALS

DX 1000 1 11 1 19 1 1 /DY 1000 / defaults to last specified boxDZ 10 / defaults to last specified boxPORO 0.19 / defaults to last specified boxPERMX 230 / defaults to last specified boxTOPS 6845 / defaults to last specified boxTOPS 6872 1 11 1 19 2 2 /TOPS 6901 1 11 1 19 3 3 /TOPS 6933 1 11 1 19 4 4 /

/

-------- ARRAY CONSTANT ----- BOX -----EQUALS

TRANY 1000 1 11 1 19 1 1 /PORV 1000 / defaults to last specified box

/

146 Keywords FrontSim User GuideEQUIL

EQUIL Equilibration data specificationThe keyword sets the contacts and pressures for conventional hydrostatic equilibrium.

Default values can be specified before the slash by a null repeat count of the form n*, where n is the number of consecutive items to be defaulted.

1 Datum depth

In problems containing dissolved gas or vaporized oil, if RS or RV vs. depth tables are not provided (see items 7 and 8), the datum depth must lie at the gas-oil contact.


2 Pressure at the datum depth.

• UNITS: METRIC: barsa, FIELD: psia

3 Depth of the water-oil contact (for three-phase or oil-water problems) or

Depth of the gas-water contact (for gas-water problems).

This value is ignored in single-phase and oil-gas problems.

The contact can lie below the bottom of the reservoir if there is no mobile water initially present.

• DEFAULT: Contact lies below the bottom of the reservoir.

Note Contact depths cannot be defaulted if the model is being initialized with Capillary Pressure.

4 Oil-water capillary pressure at the water-oil contact (for three-phase or oil-water problems) or

Gas-water capillary pressure at the gas-water contact (for gas-water problems).

This value is ignored in single-phase and oil-gas problems.

Capillary pressures rather than saturations are used in order that more than one saturation table may be used in an equilibration region.


Note FrontSim only supports a value of zero in this field. Any other value will be reset to zero.

5 Depth of the gas-oil contact.

This value is ignored in single-phase, oil-water and gas-water problems.

• DEFAULT: Contact lies above the top of the reservoir.

Note Contact depths cannot be defaulted if the model is being initialized with Capillary Pressure.

6 Gas-oil capillary pressure at the gas-oil contact.

This value is ignored in single-phase, oil-water and gas-water problems.


SPECIALx FRONTSIM



FrontSim User Guide KeywordsEQUIL

147

Note FrontSim only supports a value of zero in this field. Any other value will be reset to zero.


• DEFAULT: 0.0Black Oil cases only 7 Integer selecting the type of initialization for live black oil.

A positive integer causes the dissolved gas concentration in undersaturated oil to be calculated from either an Rs versus Depth table or a Pb versus Depth table provided for this equilibration region, subject to an upper limit equal to the saturated RS value at the local pressure. The Rs versus Depth table is entered using keyword RSVD. The Pb versus Depth table is entered using keyword PBVD.

A zero or negative value causes the dissolved gas concentration in under-saturated oil to be set equal to the saturated Rs. In this case, an Rs versus Depth or a Pb versus Depth table need not be provided, but the datum depth (Item 1) must coincide with the gas-oil contact, that is the bubble point is set to the local pressure at the reference depth).

This value is ignored if dissolved gas is not present in black oil runs.

This value is ignored in compositional runs.

• DEFAULT: 0Black Oil cases only 8 Integer selecting the type of initialization for black oil runs with wet gas.

A positive integer causes the vaporized oil concentration in undersaturated gas to be calculated from either an Rv versus Depth table or a Pd versus Depth table provided for this equilibration region, subject to an upper limit equal to the saturated Rv value at the local pressure. The Rv versus Depth table is entered using keyword RVVD. The Pd versus Depth table is entered using keyword PDVD.

A zero or negative value causes the vaporized oil concentration in under-saturated gas to be set equal to the saturated Rv at the local pressure. In this case, an Rv versus Depth or a Pd versus Depth table need not be provided, but the datum depth (Item 1) must coincide with the gas-oil contact (that is the dew point is set to the local pressure at the reference depth).

This value is ignored if vaporized oil is not present in black oil runs.

This value is ignored in compositional runs.

• DEFAULT: 0

9 Integer (N) defines the initial fluids in place calculation.

N = 0: Causes the simulator to set the fluid saturations in each grid block according to the conditions at the centre of the block. This produces a steady-state solution, but the fluids in place will not be accurate if a contact passes near the centre of a large grid block.

FrontSim only N ≠ 0: FrontSim will compute a volumetric average for the cell. This computation is not exactly equivalent to the ones used by ECLIPSE 100 and ECLIPSE 300.

Note If the data set id initialized with oil water capillary pressure or the model is a 3 phase model N ≠ 0 will have no effect unless OPTIONFS item 29 is set to 1

148 Keywords FrontSim User GuideEQUIL

Not FrontSim N < 0: Causes the simulator to set the fluid saturations in each grid block to the block average saturation, taking into account the block geometry and the fluid contact. This usually results in disperse saturation distribution near the fluid contact.

Not FrontSim N > 0: Causes the simulator to set the fluid saturations in each grid block to the block average saturation, taking into account the block geometry and the fluid contact. This usually results in disperse saturation distribution near the fluid contact.

• DEFAULT: 0

Figure 6.1 Effect of Item 9 on saturation definition

10 Integer selecting the type of initialization in the compositional case.

For a gas-water run, the data is entered as for an oil-water system - that is the contact depth and capillary pressure as items 3 and 4.

Fine grid equilibration cannot be used with options 2 and 3.

See "Initializing the Study" in the "FrontSim Technical Description" for more details of the initialization of compositional studies.

Possible values are:

1: Continuous hydrocarbon phase initial state (that is no gas-oil contact in the reservoir). This includes super critical fluids which make a smooth transition from a gas to an oil.

2: Gas-oil contact, with vapor composition specified at contact. Pressure at datum depth will be set to retrograde dew point pressure.

FrontSim User Guide KeywordsEQUIL

149

3: Gas-oil contact, with liquid composition specified at contact. Pressure at datum depth is set to bubble point pressure.

• DEFAULT: 1

11 If this is set to 1 the field pressure is not set to the saturation pressure at the contact if options 2 or 3 are selected in argument 10.

150 Keywords FrontSim User GuideEXCEL

EXCEL Requests run summary output to be in Excel formatThis keyword requests that the run summary output, generated by using the RUNSUM keyword, should be written in a format that can be easily imported into Excel.

ECLIPSE 100 only If this keyword is used, the run summaries is output to a separate file, rather than appended to the end of the Print file. (There is no need to use the keyword SEPARATE with EXCEL.) The separate Run Summary file name is the root with the extension RSM.

ECLIPSE 300, FrontSim The Run Summary file name is the root with the extension RSM. This separate file is automatically generated.

Columns of data are tab-delimited. The file can be imported into Excel by using the File>Open option from within the spreadsheet. No further commands are required; the import wizard can by finished immediately without any further steps.

The EXCEL keyword has no associated data.0ECLIPSE 300, FrontSim Note The SEPARATE keyword is not applicable in ECLIPSE 300.

Example


SPECIALx FRONTSIM

RUNSPECGRIDEDITPROPSREGIONSSOLUTION

x SUMMARYSCHEDULE

EXCEL

FrontSim User Guide KeywordsFAULTS

151

FFAULTS Specifies faults for later editing

This keyword is used to define a set of faults, which can subsequently have their transmissibilities (and diffusivities) modified using the keyword MULTFLT.

The FAULTS keyword is followed by any number of records, each containing the following items of data, and each terminated with a slash (/):

1 Fault name (up to 8 characters)

The fault is made up of all the segments with the same name. The segments may be placed in any order.

2 Lower I-coordinate of cells along the fault (IX1)

3 Upper I-coordinate of cells along the fault (IX2)

IX1 must equal IX2 if the face (item 8) is X or I

4 Lower J-coordinate of cells along the fault (IY1)

5 Upper J-coordinate of cells along the fault (IY2)

IY1 must equal IY2 if the face (item 8) is Y or J

6 Lower K-coordinate of cells along the fault (IZ1)

7 Upper K-coordinate of cells along the fault (IZ2)

IZ1 must equal IZ2 if the face (item 8) is Z or K

8 Face of the fault

This should be one of X, Y, Z or I, J, K.ECLIPSE 100/FrontSim If negative direction transmissibility multipliers, MULTX-, MULTY-, or MULTZ-, are

enabled, then the face may also be one of X-, Y-, Z- or I-, J-, K-.


Notes• The FAULTS keyword may be used more than once within the GRID section.

• The faults defined here are only used as a convenient way of varying the transmissibility along the fault trajectory with the MULTFLT keyword. The generation of the non-neighbor connections is still governed by the corner-point geometry, and does not depend on the fault definitions in the FAULTS keyword (except that keyword MULTFLT modifies any non-neighbor connection transmissibilities across named fault segments).


SPECIALx FRONTSIM

RUNSPECx GRID


152 Keywords FrontSim User GuideFAULTS

Example

FAULTS-- IX1 IX2 IY1 IY2 IZ1 IZ2 FACE'zigzag' 1 1 1 2 1 4 X /'zigzag' 2 2 2 2 1 4 Y /'zigzag' 2 2 3 4 1 4 X /'zigzag' 3 3 4 4 1 4 Y /'zigzag' 3 3 5 6 1 4 X /'zigzag' 4 4 6 6 1 4 Y /'zigzag' 4 4 7 8 1 4 X /'zigzag' 5 5 8 8 1 4 Y /'zigzag' 5 5 9 10 1 4 X /'zigzag' 6 6 10 10 1 4 Y /'block' 19 19 20 30 1 4 X /'block' 30 30 20 30 1 4 X /'block' 20 30 19 19 1 4 Y /'block' 20 30 30 30 1 4 Y //

FrontSim User Guide KeywordsFDM9PNT

153

FDM9PNT Specify finite difference methodSpecifies the finite difference method to use for solving the pressure equation and the resulting fluxes. If this keyword is not set, by default a standard finite difference method is used. If specified explicitly, a generalized finite difference method is used.

FDM9PNT has no parameters.

Note If full tensor is used, FDM9PNT must also be set.

Caution FDM9PNT is not compatible with Local Grid Refinements (LGR) or Non Neighbor Connection (NNC).

Note Under some circumstances the use of this method may result in jacobian matrices which are not positive definite. This is likely to occur with grids that are not orthogonal. If this happens the multigrid solver will fail. It may be possible to run the data set using a value of 1 in FSSOLVE. It may also be necessary to limit the length of the timestep.


x FRONTSIMx RUNSPEC


154 Keywords FrontSim User GuideFIELD

FIELD Field units are to be used This indicates that field units are to be used. Note that the default unit convention is METRIC.

The keyword has no associated data.x ECLIPSE 100x ECLIPSE 300



FrontSim User Guide KeywordsFIPNUM

155

FIPNUM Fluid-in-place region numbersThe keyword should be followed by one integer for every grid block in the current input box, specifying the fluid-in-place region to which it belongs.

A balance sheet showing fluid in place and cumulative flows to and from wells and other regions is produced for each fluid-in-place region at every report time, provided the Balance flag is set in the RPTSCHED keyword.

Grid blocks are ordered with the X axis index cycling fastest, followed by the Y and Z axis indices. Repeat counts may be used for repeated values (for example 115*2). Note that spaces may not be inserted on either side of the asterisk.

Any grid blocks not assigned a value of FIPNUM when the end of the REGIONS section is reached are assigned to region 1.

ExampleWith NDIVIX=8, NDIVIY=6, NDIVIZ=5 and no input BOX set:


SPECIALx FRONTSIM



FIPNUM40*2 8*140*3 8*140*4 8*140*5 8*140*6 8*1 /

156 Keywords FrontSim User GuideFLUXNUM

FLUXNUM Identifies extent of each flux regionThe keyword is used with the Flux Boundary option to define regions that can be run as separate models with boundary fluxes defined in a previous full field run.

The keyword should be followed by one integer for each grid cell in the full field model, specifying the flux region number to which it belongs.

Any cells not explicitly assigned a FLUXNUM value will be defaulted to a value of 1. Set FLUXNUM to zero explicitly for any cells not required in flux regions.

The FLUXNUM keyword must be used in both the full-field (DUMPFLUX) run and to identify the cells belonging to each flux region. The DUMPFLUX keyword must have been entered previously.

Notes1 FrontSim currently supports only the output of fluxes from a full field run, that is the

DUMPFLUX run. The reduced run, that is USEFLUX, is not supported.

2 The Flux boundary license is not required.

3 The use of FLUXNUM for defining and editing regions and their properties is not supported. Care should be taken when converting ECLIPSE datasets to FrontSim.

Examples

Example 1To establish a single 2*2*2 flux region in a 4*4*3 field:


SPECIALx FRONTSIM

RUNSPECx GRID


FLUXNUM1 1 0 01 1 0 00 0 0 00 0 0 01 1 0 01 1 0 00 0 0 00 0 0 016*0 /

FrontSim User Guide KeywordsFLUXNUM

157

Example 2To define 9 separate flux regions in a 4*4*3 field:

FLUXNUM1 1 2 21 1 2 23 3 3 34 4 4 45 5 5 56 7 8 86 7 8 86 7 8 816*9 /

158 Keywords FrontSim User GuideFLUXSIDE

FLUXSIDE Flux boundary conditionsd Specifies the volumetric fluxes into or out of an area of cells at the edge of the reservoir. The

FLUXSIDE keyword operates on a subset of the cells on one of the six faces.

1 LGR name

• DEFAULT: GLOBAL

2 Grid face

One of LEFT, RIGHT, FRONT, BACK, TOP, BOTTOM.

3 Volumetric flow through the specified area, at reservoir conditions. Positive flow indicates flow into the cell, while negative flow indicates flow out of the cell.

1* (default value) turns off flows specified at previous time steps.

• UNITS: METRIC: Rm3/D, FIELD: RB/D

4 First index axis 1

5 Last index axis 1


7 Last index axis 2.

If the flux is set on the TOP(K=1) or BOTTOM(K=NZ) the indices are the I and J coordinates of the cells. See Figure 6.2.

Figure 6.2 Reservoir boundaries

When the flux is defined over a set of cells, the flow into each block is the total flux scaled by cell(area*perm)/total(area*perm), where:

area is the area of the cell interface at the boundary, and

perm is the permeability in the direction normal to the cell interface.

If FLUXSIDE is applied on a local grid, the local grid has to be at the boundary of the global grid, that is, the conditions must be applied to the boundary of the simulation region.



x SCHEDULE

FrontSim User Guide KeywordsFLUXSIDE

159

Example

FLUXSIDEGLOBAL LEFT 160 1 4 1 4 /

160 Keywords FrontSim User GuideFLUXTYPE

FLUXTYPE Specify type of flux boundary conditionThe FLUXTYPE keyword specifies the type of boundary conditions to be used for the reduced run by ECLIPSE.

The boundary conditions supplied from the FrontSim full field run are used in the ECLIPSE reduced run. FrontSim allows two types of boundary condition:

• Flow boundary conditions supply the boundary fluxes for each phase from the full field run.

• Pressure boundary conditions use the pressures, saturations, Rs and Rv values from the full field run as boundary conditions for the reduced run in ‘halo’ cells surrounding the reduced region.

The same type of boundary condition must be used in both the full field run (DUMPFLUX) and the reduced run (USEFLUX).

The keyword is followed by a single item to select the chosen boundary condition, terminated by a slash (/).

1 Type of boundary condition

'FLUX': Use flows of oil, water and gas from the full field run as boundary conditions on the reduced run

'PRESSURE': Use pressures and saturations from the full field run in ‘halo’ cells adjoining the reduced flux region as boundary conditions on the reduced run.

• DEFAULT: 'FLUX'

If this keyword is not present in the data file, FLUX boundary conditions are used.

Note The flows are derived by multiplying the average flow of all phases by the relative mobility of each phase. This means that in situations where the effect of gravity is important the boundary conditions may be different from those obtained using ECLIPSE Blackoil to generate the FLUX file. This is most likely to affect 3-phase models where there are vertical flows out of the Flux Region.

ExampleTo establish pressure boundary conditions:

x ECLIPSE 100ECLIPSE 300

x SPECIALx FRONTSIM

RUNSPECx GRID


FLUXTYPE'PRESSURE' /

FrontSim User Guide KeywordsFRONTSIM

161

FRONTSIM Accept only FrontSim keywordsThis keyword causes FrontSim to generate an error message for any ECLIPSE keywords in the dataset that are not supported by FrontSim. If this keyword is not included, FrontSim will ignore any such unsupported ECLIPSE keywords.

This keyword will also force ECLIPSE Office to set the simulator to FrontSim when importing the dataset. If this keyword is omitted, ECLIPSE Office will default the simulator to ECLIPSE Black-oil when importing a dataset; the user can then manually set the simulator to FrontSim on the 'Case Definition' panel in the ECLIPSE Office Data Manager.


x FRONTSIMx RUNSPEC


162 Keywords FrontSim User GuideFSSOLVE

FSSOLVE Specifies equation solverThis keyword is used to specify the equation solver.

The keyword is followed one record, and is terminated with a slash (/).

1 Solvertype

An integer value of 1 or 2 where:

1 = the original solver, a one-level iterative solver

2 = Algebraic MultiGrid Solver (AMG)

• DEFAULT: 2

Note Option value of 2 is only valid for compressible runs.

Example



x SCHEDULE

-- Turn on the AMG SolverFSSOLVE2/

FrontSim User Guide KeywordsFSWEAKW

163

FSWEAKW Reducing material balance errorsFSWEAKW triggers an algorithm for reducing material balance error (MBE) when computing streamlines in wells identified as weak wells.

One important contribution to MBE comes from computing streamlines in cells having divergence (sources and sinks), at the same time as having both in-flux and out-flux. This is the case for wells that are ‘flooded’ by ‘stronger’ wells and are denoted as weak wells.

Assuming incompressible flow, the sum of all rates of streamlines tracked to the well must equal the divergence in the cell. In order to make this happen, the algorithm ‘selects’ the streamlines to be tracked to the center of the cell.

Assume a symmetrical case as in Figure 6.3, where the flux through cell walls is denoted .

• Red lines represent streamlines tracked to the well. Thus the sum of rates of those streamlines equals the divergence in the cell.

• Green lines represent streamlines tracked through the well block. They thus make no contribution to the production/injection rate for this well.

The keyword takes no parameters. Figure 6.3 Symmetrical streamlines in a cell



x SCHEDULEFwall

i

164 Keywords FrontSim User GuideGADJUST

GGADJUST Corrects diagonal permeability tensor

Transforms the permeability tensor from local coordinates to the global coordinate system.

When you supply permeabilities under the PERMX, PERMY and PERMZ keywords, which are actually PERMI,PERMJ,PERMK, GADJUST causes the permeabilities to be transformed into the equivalent tensor permeabilities in the global coordinate system. That is, when you supply a permeability tensor that is diagonal with respect to the I,J,K directions, GADJUST generates the correction. (Most other simulators, including ECLIPSE 100, always assume that the permeability tensor is diagonal regardless of the grid geometry.)

The cell coordinate directions are determined by the tangent vectors as described below.

In a 3-dimensional grid, for example, the coordinates of a corner point cell can be expressed in terms of the coordinates ξ, η, ζ of the reference cell .

The coordinates are given by:

[EQ 6.6]

where (xi, yi, zi) denote the corner points of the cell and the ψi terms are the bilinear functions being 1 in corner point i of the reference cell and zero in all other corner points.

The tangent vectors are given by

[EQ 6.7]

and

[EQ 6.8]

and

[EQ 6.9]

evaluated at the center of the cell.

By defining the matrix T = [t1, t2, t3] the transformation of the diagonal permeability tensor

K to the full permeability tensor is be given by


x FRONTSIMRUNSPEC


0 1,[ ] 0 1,[ ]× 0 1,[ ]×

r ξ η ζ, ,( )xyz

xiψi ξ η ζ, ,( )i 1=

8

∑

yiψi ξ η ζ, ,( )i 1=

8

∑

ziψi ξ η ζ, ,( )i 1=

8

∑

= =

t1ξ∂

∂ r

ξ∂∂ r

------------=

t2η∂∂ r

η∂∂ r

-------------=

t3ζ∂

∂ r

ζ∂∂ r

------------=

K̃

K̃ TKTt=

FrontSim User Guide KeywordsGAS

165

GAS Run contains GASThis keyword indicates that a run contains gas. This may be specified whenever a gas phase exists or could exist.

The keyword GAS takes no arguments.




166 Keywords FrontSim User GuideGCONINJE

GCONINJE Injection rate controls/limits for groups/fieldThis keyword specifies the injection targets and limits for groups.

The keyword is followed by any number of records, each containing the following items of data, and each terminated with a slash (/).

Default values can be specified before the slash by a null repeat count of the form n*, where n is the number of consecutive items to be defaulted.


1 Group name or group name root

or FIELD (for field rate control data)

A group name root, enclosed in quotes and ending with an asterisk (*), can be used to refer to several groups in one record.

2 Phase to which the following controls/limits apply

WATER: Water injection controls.

GAS: Gas injection controls.

OIL: Oil injection controls.

3 Injection rate control mode

NONE: No immediate control of injection rate

RATE: The group/field surface injection rates of the phase in Item 2 are controlled to meet the target specified in Item 4.

RESV: The group/field reservoir volume injection rate of the phase in Item 2 are controlled so that the total reservoir volume injection rate of the group/field meets the target specified in Item 5.

VREP: The group/field reservoir volume injection rate of the phase in Item 2 are controlled so that the total reservoir volume injection rate of the group/field equals its production voidage rate times the voidage replacement fraction specified in Item 7.

• DEFAULT: NONE

4 Surface injection rate target or upper limits for the phase in Item 2

• UNITS: sm3/day (METRIC), stb/day for oil or water (FIELD), Mscf/day for gas (FIELD)

• DEFAULT: No target

5 Total reservoir volume injection rate target or upper limits

• UNITS: rm3/day (METRIC), rb/day (FIELD)

• DEFAULT: No targetRequired but not used by FrontSim

6 1*

7 Total voidage replacement fraction target or upper limits


Note Surface rate control is not allowed in compositional mode.


SPECIALx FRONTSIM


x SCHEDULE

FrontSim User Guide KeywordsGCONINJE

167

ExampleGCONINJEFIELD GAS REIN 2* 1.0 /GR1 WATER RESV 1* 15000 //

168 Keywords FrontSim User GuideGCONPROD

GCONPROD Production rate controls/limits for groups/fieldThis keyword sets the production rate targets and limits for groups using the guide rate method of group control.


The records may be terminated at any item after Item 1. The remaining items assume their default values. Default values can be specified before the slash by a null repeat count of the form n*, where n is the number of consecutive items to be defaulted.


1 Group name or group name root or FIELD (for field rate control data)


2 Production rate control mode

NONE: No immediate control of production rate

ORAT: Group/field oil production rate is controlled to meet the target specified in Item 3

WRAT: Group/field water production rate is controlled to meet the target specified in Item 4

GRAT: Group/field gas production rate is controlled to meet the target specified in Item 5

LRAT: Group/field liquid production rate is controlled to meet the target specified in Item 6

RESV: Group/field reservoir fluid volume production rate is controlled to meet the target specified in Item 14

3 Oil production rate target or upper limit



4 Water production rate target or upper limit



5 Gas production rate target or upper limit

• UNITS: sm3/day (METRIC), Mscf/day (FIELD)


6 Liquid production rate target or upper limit



7 Procedure on exceeding a maximum rate limit

NONE: Do nothing

CON: Shut worst-offending connection in worst-offending well

+CON: Shut worst-offending connection and all below it in worst-offending well (see keyword COMPORD)


SPECIALx FRONTSIM


x SCHEDULE

FrontSim User Guide KeywordsGCONPROD

169

WELL: Shut or stop worst-offending well (Item 9 in keyword WELSPECS)

RATE: Control group/field production rate to equal the violated upper limit

• DEFAULT: NONE

The ’worst-offending’ well or connection is the one producing the highest ratio of the violating phase.

The procedure specified here applies to the four rate limits set in Items 3 - 6, except for a rate limit that is a control target as specified in Item 2. For control targets, the procedure i always rate.


8 1*


9 1*


10 1*


11 1*


12 1*


13 1*

14 Reservoir fluid volume production rate target or upper limit

The procedure on exceeding this limit is always RATE.

• UNITS: rm3/day (METRIC), rb/day (FIELD)

• DEFAULT: No target or limit

Note Surface rate control is not allowed in compositional mode.

ExampleThe field has a target oil rate of 10,000 stb/day of oil, to be shared between the wells in proportion to their guide rates or potentials, subject to their individual rate and pressure limits.

GCONPRODFIELD ORAT 10000 //

170 Keywords FrontSim User GuideGECON

GECON Economic limit data for groups and the fieldThe keyword is followed by any number of records, each containing the following items of data, and each terminated with a slash (/).

The records may be terminated at any item after item 1. The remaining items assume their default values. Default values can be specified before the slash by a null repeat count of the form n*, where n is the number of consecutive items to be defaulted.


1 Group name or group name root or FIELD (for field economic limit data)




• DEFAULT: 0.0

If the group (or field) oil production rate falls below the specified minimum, all the producers in the group (or field) are shut. A zero or negative value switches off this constraint.



• DEFAULT: 0.0

If the group (or field) gas production rate falls below the specified minimum, all the producers in the group (or field) are shut. A zero or negative value switches off this constraint.

4 Maximum group or field water cut (water-liquid ratio)



5 Maximum group or field gas-oil ratio

• UNITS: sm3/sm3 (METRIC), Mscf/stb (FIELD)


6 Maximum group or field water-gas ratio

• UNITS: sm3/sm3 (METRIC), stb/Mscf (FIELD)


7 Workover procedure on exceeding water cut, GOR or WGR limit

NONE: Do nothing

CON: Shut worst-offending connection in worst-offending well

+CON: Shut worst-offending connection and all below it in worst-offending well

WELL: Shut the worst-offending well

• DEFAULT: NONE


SPECIALx FRONTSIM


x SCHEDULE

FrontSim User Guide KeywordsGECON

171

Example

GECONGRUP1 2000 1* 0.8 10.0 1* CON Y /GRUP2 1000 /FIELD 4000 //

172 Keywords FrontSim User GuideGEOFLOFS

GEOFLOFS Setup Simple Simulations for Flow Analysis on Geologic ModelsThis keyword can be used to set up custom incompressible displacement simulations using up to three immiscible fluid phases labeled as oil, water and gas. Typically, such simulations are used for the purpose of screening geological models or grid design and upscaling validation. More details can be found in the "Geologic Model Screening" in the "FrontSim Technical Description".

The data for these simulations is organized using the standard data file sections, such as RUNSPEC, GRID,…and so on, as done for normal FrontSim runs. However, it is possible to skip certain sections of data if the required data is provided through the GEOFLOFS keyword. For example, the simplest GEOFLOFS simulation using pressure boundary conditions and no wells can be performed with data provided in just the RUNSPEC and the GRID sections.

For progressively complex GEOFLOFS simulations data needs to be provided in the PROPS, REGIONS, SOLUTION and SCHEDULE sections. PVT data is always read from the GEOFLOFS keyword and only one set of properties is applicable for the entire model. Hence, multiple PVT or rock regions are currently not supported. However, multiple saturation regions and end point scaling, and multiple equilibration regions can be used with GEOFLOFS. Alternatively, the model can be initialized by enumeration.

By default GEOFLOFS simulations report a set of summary vectors, a streamline time-of-flight analysis table in the print file, streamline (.sln) files, restart files and a separate .fscat file with specific well data reported in Petrel point data format.

Simulations have been classified into two broad types. They are based primarily on the boundary conditions applied to induce flow and are classified as simulation with wells and without wells. Simulation without wells apply pressure gradient across opposite faces of the model grid.

The keyword is followed by three data records. The first record defines the type of simulation and fluid viscosity and density. The second record defines simulation operating conditions, and the third record includes options for more advanced runs. Each record is terminated with a slash (/).

Record maybe terminated early by a slash (/), the remaining items taking their default values. Default values can be specified before the slash by a null repeat count of the form n*, where n is the number of consecutive items to be defaulted.

The data items in each record are:

Record 1This record defines the type of simulation and fluid properties.

1 Type of simulation. This parameter accepts the following integers as input.

1 = Reserved for future use.

2 = simulation with well controls as defined in Record 2 and the SCHEDULE section.

3 or 4 = 2-phase displacement simulation using pressure boundary conditions on the edges of the grid (no wells). Type 3 is for flow from Left to Right and no-flow at the back and front edges of the grid. Type 4 is for flow from Back to Front and no-flow on the left and right edges. Boundary conditions are defined in "Record 2" on page 173.


x FRONTSIMx RUNSPEC


FrontSim User Guide KeywordsGEOFLOFS

173

2 Viscosity of phase labeled as oil.

• Default = 1 cp.

3 Viscosity of phase labeled as water.

• Default = 1 cp.

4 Viscosity of phase labeled as gas.

• Default = 1 cp.

5 Density of phase labeled as oil.

• Default = (1000 kg/m3 or 62.428 lb/cu.ft)

6 Density of phase labeled as water.


7 Density of phase labeled as gas.


End data record with a slash (/).

Record 2This record can be used to define simple production/injection or pressure boundary conditions depending on the type of simulation chosen in Record 1. More complex operating conditions can be defined by choosing to use control data in the SCHEDULE section.

1 Producer Controls / Pressure Gradient.

For simulation type = 2: this parameter remains defaulted (1*). Producer controls must be specified in the SCHEDULE section. It is recommended to use producers on bhp and injectors on rate control or both injectors and producers on bhp control.

For simulation type = 3 or 4: Enter the value of the pressure drop to be applied across the grid edges. If a negative value is provided the normal direction of the pressure gradient will be reversed. Default = 50% of the computed initial pressure. See "Record 3" on page 174.

2 Injector Controls.

Enter fraction of HCPV to be injected over the duration of the simulation. (Duration of simulation is defined by parameter 3 below. If the fraction of HCPV injected is fulfilled before this time the simulation will stop earlier.)

• For simulation type = 2, Default (1*) = use injection controls as specified in SCHEDULE section.

• For simulation type = 3 or 4, Default (1*) = 1.0 HCPV.

3 Simulation Duration. Enter number of years.

• For simulation type = 2, Default (1*) = use time steps as specified in SCHEDULE section.

• For simulation type = 3 or 4, Default (1*) = 10 years. [1 year = 365 days]

4 Number of Pressure Computations. Enter number.

• For simulation type = 2, Default (1*) = 1. However, if item 3 above is defaulted then follow the SCHEDULE section.

• For simulation type = 3 or 4, Default (1*) = 1.


5 Number of Streamlines to launch. Enter number. Only used for simulation type 3 and 4. Most often FrontSim will not be able to launch the exact number specified - but it will compute one that is as close as possible.

• Default = calculated.


Record 3This record provides options for selecting gravity, using special relative permeability and initialization data. In addition, option to suppress default output and choose a different pressure solver are provided.

1 Turn on Gravity (Y/N).

• Default = N.

2 Use relative permeability data defined in the PROPS section. (Y/N).

• Default = N.

In the default case all simulations will use straight line relative permeability with endpoints either 0 or 1 as appropriate.

For Type 3 and 4 simulations the default, i.e. linear relative permeability, is always used.

3 Use contacts/enumeration as defined in the SOLUTION Section. (Y/N).

• Default = N.

In the default case all simulations are initialized with a single phase using a hydrostatic pressure gradient and a datum based on the mean model depth. For all combination of phases the initialized phase is oil, except in gas-water systems where it is gas.

For Type 3 and 4 simulations the default is always used; the modeled is initialized with oil and the displacing phase is water.

4 Use One-Level Pressure Solver. (Y/N).

• Default = N.

The AMG solver is used by default in order to process large grids efficiently. Since the AMG solver currently works for compressible cases only, a small amount of rock compressibility is introduced. This will not change the solution appreciably in most cases. In case of any complications or need to strictly adhere to incompressible conditions set this default to 'Y' to enable the alternate solver.

5 Suppress output of bulk data (GRID, INIT, RESTART and Streamline Files) (Y/N).

Y: over ride all GEOFLOFS default bulk data or other user requested output directives

• Default = N.


Notes1 For Type 3 and 4 simulations number of phases is always two. If three phases are defined

the simulation will default to oil and water.

2 When no phases are defined in the RUNSPEC section the default is to use oil and water.


175

3 A Base FrontSim license will allow unlimited number of threads by default when run contains a valid GEOFLOFS keyword. This is only limited by the number of processor (cores) on the machine - or if a value is specified by THREADFS.

4 Compositional fluids and IOR tracer scale up models and related keywords are not supported.

5 Conversion of wells (e.g. from producer to injector) is not supported with GEOFLOFS.

Default Reports1 Summary file (*.Snnn or *.UNSMRY)

For Type 2 simulations (with wells):

Field Recovery Efficiency, FOE

Field Oil production rate, FOPR

Field Cum. Oil production, FOPT

Field Water Cut, FWCT

Field Water Injection rate, FWIR

Field Cum. Water Injection, FWIT

Well Oil production rate, WOPR

Well Cum. Oil, WOPT

Well Water-cut, WWCT

Well Drainage Efficiency or Recovery Efficiency, WPDRAIN

Well Water injection rate, WWIR

Well Cum water injected, WWIT

Well Waterflood Efficiency, WPFLOOD

For Type 3 and 4 simulations (without wells):

Recovery Efficiency, FOE

Edge Oil production rate, EOPR

Edge Cum. Oil production, EOPT

Edge Water Cut, EWCT

Edge Water Injection rate, EWIR

Edge Cum. Water Injection, EWIT

2 Print File (.PRT)

Reports a table of the average inverse of time-of-flight for streamlines.

The average is computed for intervals each representing 1% of the total number of streamlines except the endpoints which represents 0.5%.

3 Streamline Files (.SLNxx)

Reports the same properties for streamlines as obtained using BASIC mnemonic in the RPTSLN keyword.

4 Restart Files (*.Xnnnn or *.UNRST)


Reports the same properties for streamlines as obtained using BASIC and TOF mnemonics in the RPTRST keyword.

5 Points Data (.fscat) for Type 2 simulations only.

This file uses the Petrel format for storing points data. Point data is created at the grid surface location for every well. This can be used to produce maps in Petrel. For multiple realizations, mean and variance maps to represent uncertainty can be created. The following properties are reported.

a Pore Volume, WPPOREVProducers Only b Initial Oil-in-place, WPOIP at t=0 (WPIOIP) Producers Only c Initial Oil production rate, WOPR at t=0 (WIOPR)

Producers Only d Cumulative Oil Produced, WOPT at t=end (WFOPT) Producers Only e Drainage Efficiency or Recovery Efficiency (WFOPT/WPIOIP) Producers Only f Time of water breakthrough (wcut >= 0.9)Injectors Only g Initial water injection rate WWIR at t=0 (WIWIR)

Injectors Only h Cumulative water injected WWIT at t=end (WFWIT) Injectors Only i Waterflood Efficiency (Offset cumulative Oil/WFWIT)

For simulation with multiple time steps the items a, b, e, and i are averages.

Examples

Example 1For a given grid to analyze flux distribution across fine scale layers conduct a left-to-right flow experiment.

Example 2For a given oil reservoir with a gas cap, aquifer and existing wells perform quick analysis of connectivity uncertainty using ‘colored water’ simulation for 100 realizations.

GEOFLOFS3 ///


177

We set up an incompressible tracer simulation that will inject 2 HCPV of water in 20 years.

--RUNSPEC sectionTITLEExample 2OILWATERGASFIELDDIMENSGEOFLOFS2 /1* 2.0 20 //………-- Schedule sectionSCHEDULEWELSPECS……..……..COMPDAT…….…….WCONPROD‘P1’ OPEN BHP 5* 14.7 /………..

178 Keywords FrontSim User GuideGOCADGRI

GOCADGRI Recognize stratigraphic gridThis keyword is used to specify that FrontSim should recognize a stratigraphic grid (.sgrid file extension).

Each record consists of two items of data, terminated with a slash.

1 File name: the name of the .sgrid file (the .sgrid filename extension is required)

2 Top layer: an explicit statement to indicate which layer in the model is considered the top of the reservoir. The parameter takes the value of either 1 or NZ; the default is 1.

Example


x FRONTSIMRUNSPEC


GOCADGRIfrontsim.sgrid NZ /

FrontSim User Guide KeywordsGOCADOUT

179

GOCADOUT JACTA-compatible output file to be generatedThis keyword is used to specify that FrontSim should generate an appropriate output file for JACTA.

Each record consists of seven items of data, terminated with a slash.

1 pre: frequency for generating pressure output files.

0 indicates no output

• DEFAULT: 1

2 sat: frequency for generating saturation output files.


• DEFAULT: 1

3 tof: frequency for generating time-of-flight output files.


• DEFAULT: 1

4 rvs: trigger option for generating a reservoir volume summary file (.rvs file).

• VALUE: either 1 or 0, where 0 indicates no output

• DEFAULT: 1

5 svs: trigger option for generating a surface volume summary file (.svs file).


• DEFAULT: 1

6 wpv: trigger option for generating a well pore volume file (.wpv file).


• DEFAULT: 0

7 well: trigger option for generating a rate summary file for each well (.well file).


• DEFAULT: 0

Example



x SCHEDULE

GOCADOUT-- pre sat tof rvs svs wpv well

1* 1* 0 1* 1* 1 1 /

180 Keywords FrontSim User GuideGRAVITY

GRAVITY Fluid gravities at surface conditionsThe data comprises a number of records (given by PVTNUM or 1), each terminated by a slash (/).

Each record consists of 3 items of data:

Item 1: Oil API gravity.

• DEFAULT: 45.5

Item 2: Water specific gravity (with reference to pure water).

• DEFAULT: 1.0

Item 3: Gas gravity (with reference to air).

• DEFAULT: 0.7773

Keyword DENSITY can be used as an alternative to GRAVITY.

See "Units" on page 473 for conversion formulae between gravity and density.

ExampleWith two PVT tables:


RUNSPECGRIDEDIT


GRAVITY40.1 1.16 0.852 /36.5 1.16 0.852 /

FrontSim User Guide KeywordsGRIDFILE

181

GRIDFILE Controls output of the Grid geometry fileThe keyword should be followed by one integer. Note that creation of a GRID file is the default operation for FrontSim, so the keyword can be used to switch off the GRID file creation (0 value) if required.

This value controls the amount of data written to the GRID geometry file. The possible values are:

1 Control of the GRID file output

0: No GRID file is produced

2: A GRID file is produced, containing:

Inactive cell data

Non-neighbor connection data

Local grid refinement data

• DEFAULT: 2


Example

Note FrontSim does not support the EGRID file format.


SPECIALx FRONTSIM

RUNSPECx GRID


-- No grid fileGRIDFILE0 /

182 Keywords FrontSim User GuideGUIDERAT

GUIDERAT Specifies general formula for guide ratesWhen GUIDERAT is set the computation of the individual well rates for wells under GROUP/FIELD control is assigned in proportion with the flow potential of the wells at their given bottom hole pressure limit.

The keyword has no associated data, but must be followed by a slash (/), indicating default parameters.

The flow potential is that rate that the well would have produced or injected, if the bottom hole pressure were the given BHP limit and the reservoir pressure were the current block pressure in the reservoir in the following formula:

where:

- rate at reservoir conditions

- productivity index

- reservoir pressure

- bottom hole pressure

Note This is default behavior in 2006.1 - to revert to old behavior set OPTIONFS (21).

Example


SPECIALx FRONTSIM


x SCHEDULE

GUIDERAT/

Qr PI Pr Pw–( )=

Qr

PI

Pr

Pw

FrontSim User Guide KeywordsHEATCAP

183

HHEATCAP Heat capacity for rock and fluid

Sets the heat capacity for the rock and fluid. The heat capacity must be set in order to perform temperature tracking.

1 Heat capacity per unit volume of rock

• UNITS: kJ/m3/ºK (METRIC), Btu/ft3/ºF (FIELD)

2 Heat capacity per unit volume of water


3 Heat capacity per unit volume of oil


See also keywords RTEMP, WTEMP

Example


x FRONTSIMRUNSPECGRIDEDIT


HEATCAP0.2 1 0.53 /

184 Keywords FrontSim User GuideHXFIN

HXFIN Local grid size ratios in x-direction The keyword HXFIN can be used to dictate the size ratios of each cell in a local grid refinement. It should be placed after the CARFIN keyword introducing the local grid and before the terminating ENDFIN. HXFIN applies only to cartesian refinements.

HXFIN should be followed by NX values, where NX is the total number of cells in the refined grid along the X-direction as specified in keyword CARFIN item 8. The values represent the X-direction size ratios for each the refined grid cells.

You may default the size ratios for all the refined cells belonging to a particular host cell. If no ratios are given for a host cell, it is divided up in equal proportions. Each host cell must have the size ratios of its constituent refined cells either all set or all defaulted.

Local grid refinement is described in "Local Grid Refinement" in the "FrontSim Technical Description".

ExampleTo divide a host grid of 3 layers into a refined grid of 7 layers, with splitting ratios defined for the middle layer of the host grid:


RUNSPECx GRID


NXFIN3 2 2 /HXFIN3* 1.0 2.0 2* /

FrontSim User Guide KeywordsHYFIN

185

HYFIN Local grid size ratios in y-direction The keyword HYFIN can be used to dictate the size ratios of each cell in a local grid refinement. It should be placed after the CARFIN keyword introducing the local grid and before the terminating ENDFIN. HYFIN applies only to cartesian refinements.

HYFIN should be followed by NY values, where NY is the total number of cells in the refined grid along the y-direction as specified in keyword CARFIN item 8. The values represent the y-direction size ratios for each the refined grid cells.

You may default the size ratios for all the refined cells belonging to a particular host cell. If no ratios are given for a host cell, it will be divided up in equal proportions. Each host cell must have the size ratios of its constituent refined cells either all set or all defaulted.

Local grid refinement is described in "Local Grid Refinement" in the "FrontSim Technical Description".

ExampleTo divide a host grid of 3 layers into a refined grid of 7 layers, with splitting ratios defined for the middle layer of the host grid:


RUNSPECx GRID

EDITPROPSREGIONSSOLUTIONSUMMARY

NYFIN3 2 2 /HYFIN3* 1.0 2.0 2* /

186 Keywords FrontSim User GuideHZFIN

HZFIN Local grid size ratios in z-direction The keyword HZFIN can be used to dictate the size ratios of each cell in a local grid refinement. It should be placed after the CARFIN keyword introducing the local grid and before the terminating ENDFIN.

HZFIN should be followed by NZ values, where NZ is the total number of cells in the refined grid along the Z-direction as specified in keyword CARFIN item 10. The values represent the Z-direction size ratios for each of the refined grid cells. You may default the size ratios for all the refined cells belonging to a particular host cell. If no ratios are given for a host cell, it will be divided up in equal proportions. Each host cell must have the size ratios of its constituent refined cells either all set or all defaulted.

The form of the input is analogous to HXFIN and HYFIN.


RUNSPECx GRID


FrontSim User Guide KeywordsINCLUDE

187

IINCLUDE Include the contents of another named file

The keyword should be followed by the name of a file from which input is to be taken. This file is opened, and read to the end of the file unless an ENDINC keyword is encountered. The file is then closed, and input resumed from the main file, starting from the next keyword after the INCLUDE keyword.

The INCLUDE file name may have up to 132 characters.

The data should be terminated by a slash (/).

Nested INCLUDE files are possible.

ExampleThis example causes the program to continue input from the file CASE1.PVI. At the end of that file, the program switches back to the next keyword in the current file.



INCLUDECASE1.PVI /

188 Keywords FrontSim User GuideINIT

INIT Requests output of an INIT fileThe INIT file contains a summary of data entered in the GRID and REGIONS sections.


SPECIALx FRONTSIM

RUNSPECx GRID


FrontSim User Guide KeywordsJFUNC

189

JJFUNC Activates the Leverett J-function option

This keyword can be used to activate the Leverett J-function option, which scales the water-oil and/or gas-oil capillary pressure functions according to the grid block porosity and permeability. (See "Saturation Table Scaling" in the "ECLIPSE Technical Description" for further details.)

The keyword may only be used if end-point scaling is switched on using the keyword ENDSCALE in the RUNSPEC section.

The keyword should be followed by up to six items of data terminated by a slash (/):

1 J-function flag.

WATER Requests the J-function option for the water-oil capillary pressure only.

• DEFAULT: WATER

2 Oil-water surface tension.

• UNITS: dynes/cm (METRIC, FIELD, LAB or PVT-M)

The oil-water surface tension must be supplied if the first data item is set to either WATER or BOTH.

3 Oil-gas surface tension.

• UNITS: dynes/cm (METRIC, FIELD, LAB or PVT-M)

Not currently used.

4 Alternative power for the porosity term ( )

• DEFAULT: 1/2

5 Alternative power for the permeability term ( )

• DEFAULT: 1/2

6 Permeability Direction

XY: The average of PERMX and PERMY values

X PERMX value

Y PERMY value

Z PERMZ value

• DEFAULT: XY

The J-function option scales the capillary pressure functions according to the rock porosity and permeability.

The dimensionless J-function is entered in place of the capillary pressure function, specified using either the SWFN or the SWOF family of keywords (see information written for the third or fourth column of these keywords).

The capillary pressure is then calculated as follows:

[EQ 6.10]

where

capillary pressure from the input table - SWFN or SGFN

surface tension - data item 2 or 3


SPECIALx FRONTSIM

RUNSPECX GRID


α

β

Pc Pc S( ) ST PoroPerm------------⎝ ⎠

⎛ ⎞ 1 2⁄Uconst⋅ ⋅ ⋅=

Pc S( )

ST

190 Keywords FrontSim User GuideJFUNC

cell porosity

cell permeability

and

constant depending on the unit system employed

= 0.318316 (METRIC pressure: Bar perm: mD)

= 4.61678 (FIELD pressure: Psia perm: mD)

= 0.314153 (LAB pressure: Atm perm: mD)

= 0.314153 (PVT-M pressure: Atm perm: mD).

If data item 6 is defaulted the permeability is taken as , unless the model is a cross section, in which case is taken as the appropriate horizontal permeability, or unless it is a one-dimensional model, in which the permeability is taken in the direction of the row or column of cells.

Note For the INIT file output, the above equation will define the output under the heading PCW. It is important to note that the capillary pressure chosen from the input table (SWFN) will, by default, be the maximum value.

In the above equation, the scaling factor term is expressed as follows:

[EQ 6.11]

If data items 4 or 5 are present the capillary pressure will be interpreted as follows:

[EQ 6.12]

where:

and STref are input using the STOG or STOW keywords.

Note If the SWATINIT keyword is used in conjunction with the JFUNC keyword, then the J-function scaling is ignored in regions of the field where the SWATINIT array has been set, and will use PPCWMAX instead if set. If the PCW keyword is used in conjunction with the JFUNC keyword, the input PCW array will be ignored when the J-function selects the water-oil capillary pressure.

ExampleJFUNCWATER 22.0 /

Poro

Perm

Uconst

K Kx Ky+( ) 2⁄=

K

Scaling Factor ST PoroPerm------------⎝ ⎠

⎛ ⎞1 2⁄Uconst⋅ ⋅=

Pc Pc S( ) ST Poroα

Permβ---------------

⎝ ⎠⎜ ⎟⎛ ⎞

Uconst⋅ ⋅ ⋅=

Pc Pc S( ) ST ST P( )STref-------------- Poro

Perm------------⎝ ⎠

⎛ ⎞ 1 2⁄Uconst⋅ ⋅ ⋅ ⋅=

ST P( )

FrontSim User Guide KeywordsKRG

191

KKRG Scaled end point gas relative permeabilities

The different forms of this keyword allow scaling of the relative permeability of gas within each grid block. KRG scales the Kr at the maximum gas saturation (typically at connate water), and KRGR scales the relative permeability at residual oil saturation (or critical water in a gas-water run). The keyword can only be used when the End Point Scaling option is active (keyword ENDSCALE in the RUNSPEC section).

If the KRGR keyword has not been used, the KRG keyword has the effect of scaling the relative permeability value calculated from the appropriate saturation table after the scaled saturation end points have been accounted for. Hence:

[EQ 6.13]

The relative permeability is taken to be the value at either the maximum saturation of the saturation table, or at SGU if this has been specified. This is usually equal to .

If the KRGR keyword has been used, then the scaling honors the Kr at the critical saturation (SR) of the displacing phase. When the alternative scaling using three saturation nodes is invoked by keyword SCALECRS, SR is given by

SR = 1 - SOGCR- SWL in gas/oil or gas/oil/water runs

SR = 1 - SWCR in gas/water runs

where SOGCR, SWL and SWCR are the scaled values.When the alternative scaling method is not employed, only the two nodes SGCR and SGU are used to scale the saturation endpoints, and SR is taken to be the transformed value of

SR(Table)=1.0-Sogcr(Table)-Sgco(Table)

or

SR(Table)=1.0-Swcr(Table).

Hence the two cases are:

[EQ 6.14]

[EQ 6.15]

Two keywords are provided to allow the maximum gas relative permeability to be set for each grid cell independently. These keywords are:

KRG Max gas Kr for the non-directional saturation function tables

KRGR Kr at residual for the non-directional saturation function tables

Note None of the KRG keywords should be used if gas is not present in the model. The keyword ENDSCALE should be specified in the RUNSPEC section.

Each KRG keyword should be followed by one real number for each grid block in the current input box, specifying the maximum gas relative permeability value. The data must be terminated by a slash(/).


SPECIALx FRONTSIM

RUNSPECGRIDEDIT


Krg Krg Table( )KRG GridBlock( )Krgmax Table( )

------------------------------------------=

1 Swco–

SG SR< Krg Krg Table( )KRGR GridBlock( )Krg SR( ) Table( )

----------------------------------------------=

SG SR> Krg KRGR KRG KRGR–Krgmax Krg SR( )–----------------------------------------- Krg Table( ) Krg SR( )–( )+=

192 Keywords FrontSim User GuideKRG

Grid blocks are ordered with the X-axis index cycling fastest followed by the Y and Z indices. Repeat counts may be used for repeated values (for example 10*0.21). Note that spaces must not be inserted on either side of the asterisk.

If any of the KRG* keywords are omitted in a model where they could be accepted, then the maximum gas Kr value defaults to the value used in the appropriate gas saturation function table.

If pure normalized curves are used where (1.0-SOGCR-SWL) is equal to SGU, then depending on the scaling option used (see the SCALECRS keyword) the two end-points may be equal. If this is the case both KRG and KRGR apply to the same point.and the KRGR keyword is ignored.

ECLIPSE 100 See also keywords SGU and ENKRVD in the PROPS section.

Refer to "Saturation Table Scaling" in the "FrontSim Technical Description" for more information.

Example

-- In the RUNSPEC section :DIMENS1 7 5 /ENDSCALE/-- In the PROPS section :KRG7*1.07*0.967*0.947*0.907*0.85 /

FrontSim User Guide KeywordsKRGR

193

KRGR Scaled end point gas relative permeabilitiesThe different forms of this keyword allow scaling of the relative permeability of gas within each grid block. KRG scales the Kr at the maximum gas saturation (typically at connate water), and KRGR scales the relative permeability at residual oil saturation (or critical water in a gas-water run). The keyword can only be used when the End Point Scaling option is active (keyword ENDSCALE in the RUNSPEC section).

If the KRGR keyword has not been used, the KRG keyword has the effect of scaling the relative permeability value calculated from the appropriate saturation table after the scaled saturation end points have been accounted for. Hence:

[EQ 6.16]

The relative permeability is taken to be the value at either the maximum saturation of the saturation table, or at SGU if this has been specified. This is usually equal to .

If the KRGR keyword has been used, then the scaling honors the Kr at the critical saturation (SR) of the displacing phase. When the alternative scaling using three saturation nodes is invoked by keyword SCALECRS, SR is given by

SR = 1 - SOGCR- SWL in gas/oil or gas/oil/water runs

SR = 1 - SWCR in gas/water runs

where SOGCR, SWL and SWCR are the scaled values.When the alternative scaling method is not employed, only the two nodes SGCR and SGU are used to scale the saturation endpoints, and SR is taken to be the transformed value of

SR(Table)=1.0-Sogcr(Table)-Sgco(Table)

or

SR(Table)=1.0-Swcr(Table).


[EQ 6.17]

[EQ 6.18]

Two keywords are provided to allow the maximum gas relative permeability to be set for each grid cell independently. These keywords are:

KRG Max gas Kr for the non-directional saturation function tables

KRGR Kr at residual for the non-directional saturation function tables

Note None of the KRG keywords should be used if gas is not present in the model. The keyword ENDSCALE should be specified in the RUNSPEC section.

Each KRG keyword should be followed by one real number for each grid block in the current input box, specifying the maximum gas relative permeability value. The data must be terminated by a slash(/).


SPECIALx FRONTSIM

RUNSPECGRIDEDIT


Krg Krg Table( )KRG GridBlock( )Krgmax Table( )

------------------------------------------=

1 Swco–

SG SR< Krg Krg Table( )KRGR GridBlock( )Krg SR( ) Table( )

----------------------------------------------=

SG SR> Krg KRGR KRG KRGR–Krgmax Krg SR( )–----------------------------------------- Krg Table( ) Krg SR( )–( )+=

194 Keywords FrontSim User GuideKRGR


If any of the KRG* keywords are omitted in a model where they could be accepted, then the maximum gas Kr value defaults to the value used in the appropriate gas saturation function table.

If pure normalized curves are used where (1.0-SOGCR-SWL) is equal to SGU, then depending on the scaling option used (see the SCALECRS keyword) the two end-points may be equal. If this is the case both KRG and KRGR apply to the same point.and the KRGR keyword is ignored.

ECLIPSE 100 See also keywords SGU and ENKRVD in the PROPS section.


Example-- In the RUNSPEC section :DIMENS1 7 5 /ENDSCALE/-- In the PROPS section :KRG7*1.07*0.967*0.947*0.907*0.85 /

FrontSim User Guide KeywordsKRO

195

KRO Scaled end point oil relative permeabilitiesThe different forms of this keyword scale, KRO,KRORW,KRORG, the relative permeability of oil within each grid block. KRO scales the Kr at the maximum oil saturation (typically at connate water), KRORW scales the relative permeability at the critical water saturation, and KRORG scales the relative permeability at the critical gas saturation. The keyword can only be used when the End Point Scaling option is active (keyword ENDSCALE in the RUNSPEC section).

If the KRORW and KRORG keywords have not been used, the KRO keyword has the effect of scaling the relative permeability value calculated from the appropriate saturation table after the scaled saturation end points have been accounted for. Hence:

[EQ 6.19]

The relative permeability is taken to be the value at either the maximum saturation of the saturation table or at SWL if this has been specified.

If the KRORW or KRORG keywords have been used, then the scaling honors the Kr at the critical saturation (SR) of the displacing phase. When the alternative scaling using three saturation nodes is invoked by keyword SCALECRS, SR is given by

SR = 1 - SWCR - SGL for the KRORW keyword

SR = 1 - SGCR - SWL for the KRORG keyword

where SWCR and SGCR etc. are the scaled values. When the alternative scaling method is not employed, only two nodes are used to scale the saturation end points, and SR is taken as the transformed value of for the KRORW keyword, or

for the KRORG keyword.


[EQ 6.20]

[EQ 6.21]

Note In 3-phase cases using the STONE II Model for 3-phase relative permeability (see keyword STONE2), the oil relative permeability is a function of the water and gas relative permeabilities, and hence the oil relative permeability is modified by use of the KRW and KRG keywords to scale the water and gas relative permeabilities.

Three keywords are provided to allow the maximum oil relative permeability to be set for each grid cell independently. These keywords are:

KRO Max oil Kr for the non-directional saturation function tables

KRORW KRORG Kr at critical for the non-directional tables

None of the KRO keywords should be used if oil is not present in the model. The keyword ENDSCALE should also be set in the RUNSPEC section.

Each KRO keyword should be followed by one real number for each grid block in the current input box, specifying the maximum oil relative permeability value. The data must be terminated by a slash(/).


SPECIALx FRONTSIM

RUNSPECGRIDEDIT


Kro Kro Table( )KRO GridBlock( )Kromax Table( )

------------------------------------------=

SR Table( ) 1.0 Swcr Table( ) Sgco Table( )––=

SR Table( ) 1.0 Sgcr Table( ) Swco Table( )––=

SO SR< Kro Kro Table( )KROR GridBlock( )Kro SR( ) Table( )

----------------------------------------------=

SO SR> Kro KROR KRO KROR–Kromax Kro SR( )–----------------------------------------- Kro Table( ) Kro SR( )–( )+=

196 Keywords FrontSim User GuideKRO


If any of the KRO* keywords are omitted in a model where they could be accepted, then the maximum oil Kr value defaults to the value used in the appropriate oil saturation function table.

If pure normalized curves are used where SWCR equals SWL or SGCR equals SGL, then depending on the Scaling option used (see the SCALECRS keyword) the two end-points may be equal. If this is the case, both KROW and KRORW (or KROG and KRORG) apply to the same point and the KRORW (KRORG) keyword is ignored.

ECLIPSE 100 See also keywords SWL and ENKRVD in the PROPS section.


Example-- In the RUNSPEC section :DIMENS10 1 4 /ENDSCALE/-- In the PROPS section :KRO10*0.9 10*0.98 10*1.0 10*1.0 /KRORW10*0.8 10*0.86 10*0.9 10*1.0 /

FrontSim User Guide KeywordsKRORG

197

KRORG Scaled end point oil relative permeabilitiesThe different forms of this keyword scale, KRO,KRORW,KRORG, the relative permeability of oil within each grid block. KRO scales the Kr at the maximum oil saturation (typically at connate water), KRORW scales the relative permeability at the critical water saturation, and KRORG scales the relative permeability at the critical gas saturation. The keyword can only be used when the End Point Scaling option is active (keyword ENDSCALE in the RUNSPEC section).


[EQ 6.22]








[EQ 6.23]

[EQ 6.24]








SPECIALx FRONTSIM

RUNSPECGRIDEDIT



------------------------------------------=




----------------------------------------------=


198 Keywords FrontSim User GuideKRORG






Example

-- In the RUNSPEC section :DIMENS10 1 4 /ENDSCALE/-- In the PROPS section :KRO10*0.9 10*0.98 10*1.0 10*1.0 /KRORG10*0.8 10*0.86 10*0.9 10*1.0 /

FrontSim User Guide KeywordsKRORW

199

KRORW Scaled end point oil relative permeabilitiesThe different forms of this keyword scale, KRO,KRORW,KRORG, the relative permeability of oil within each grid block. KRO scales the Kr at the maximum oil saturation (typically at connate water), KRORW scales the relative permeability at the critical water saturation, and KRORG scales the relative permeability at the critical gas saturation. The keyword can only be used when the End Point Scaling option is active (keyword ENDSCALE in the RUNSPEC section).


[EQ 6.25]








[EQ 6.26]

[EQ 6.27]








SPECIALx FRONTSIM

RUNSPECGRIDEDIT



------------------------------------------=




----------------------------------------------=


200 Keywords FrontSim User GuideKRORW






Example

-- In the RUNSPEC section :DIMENS10 1 4 /ENDSCALE/-- In the PROPS section :KRO10*0.9 10*0.98 10*1.0 10*1.0 /KRORW10*0.8 10*0.86 10*0.9 10*1.0 /

FrontSim User Guide KeywordsKRW

201

KRW Scaled end point water relative permeabilitiesThe different forms of this keyword scale the relative permeability of water within each grid block. KRW scales the Kr at the maximum water saturation (typically at a water saturation of 1.0), and KRWR scales the relative permeability at residual oil saturation (or residual gas in a gas- water run). The keyword can only be used when the End Point Scaling option is active (keyword ENDSCALE in the RUNSPEC section).

If the KRWR keyword has not been used, the KRW keyword has the effect of scaling the relative permeability value calculated from the appropriate saturation table after the scaled saturation end points have been accounted for. Hence:

[EQ 6.28]

The relative permeability is taken to be the value at either the maximum saturation of the saturation table or at SWU if this has been specified.

If the KRWR keyword has been used, then the scaling honors the Kr at the critical saturation (SR) of the displacing phase. When the alternative scaling method using three saturation nodes is invoked by keyword SCALECRS, SR is given by

SR = 1 - SOWCR - SGL in gas/oil or gas/oil/water runs

SR = 1 - SGCR in gas/water runs

where SOWCR and SGCR are the scaled values. When the alternative scaling method is not employed, only the two nodes SWCR and SWU are used to scale the saturation end points, and SR is taken to be the transformed value of or

.


[EQ 6.29]

[EQ 6.30]

Two keywords are provided to allow the maximum water relative permeability to be set for each grid cell independently. These keywords are:

KRW Max water Kr for the non-directional saturation function tables

KRWR Kr at residual for the non-directional saturation function tables

None of the KRW keywords should be used if water is not present in the model. The keyword ENDSCALE should also be specified in the RUNSPEC section.

Each KRW keyword should be followed by one real number for each grid block in the current input box, specifying the maximum water relative permeability value. The data must be terminated by a slash(/).



SPECIALx FRONTSIM

RUNSPECGRIDEDIT

x PROPSREGIONSSOLUTIONSUMMARYSCHEDULE Krw Krw Table( )KRW GridBlock( )

Krwmax Table( )-------------------------------------------=

SR Table( ) 1.0 Sowcr Table( ) Sgco Table( )––=

SR Table( ) 1.0 Sgcr Table( )–=

SW SR< Krw Krw Table( )KRWR GridBlock( )Krw SR( ) Table( )

-----------------------------------------------=

SW SR> Krw KRWR KRW KRWR–Krwmax Krw SR( )–------------------------------------------- Krw Table( ) Krw SR( )–( )+=

202 Keywords FrontSim User GuideKRW

If any of the KRW* keywords are omitted in a model where they could be accepted, then the maximum water Kr value defaults to the value used in the appropriate water saturation function table.

If pure normalized curves are used where (1.0-SOWCR-SGL) is equals to SWU, then depending on the Scaling option used (see the SCALECRS keyword) the two end-points may be equal. If this is the case both KRW and KRWR apply to the same point.and the KRWR keyword is ignored.

ECLIPSE 100 See also keywords SWU and ENKRVD in the PROPS section.


Example

-- In the RUNSPEC section :DIMENS1 7 3 /ENDSCALE/-- In the PROPS section :-------- IX1-IX2 JY1-JY2 KZ1-KZ2BOX

1 1 2 7 1 3KRW6*0.556*0.656*0.67 /

FrontSim User Guide KeywordsKRWR

203

KRWR Scaled end point water relative permeabilitiesThe different forms of this keyword scale the relative permeability of water within each grid block. KRW scales the Kr at the maximum water saturation (typically at a water saturation of 1.0), and KRWR scales the relative permeability at residual oil saturation (or residual gas in a gas- water run). The keyword can only be used when the End Point Scaling option is active (keyword ENDSCALE in the RUNSPEC section).

If the KRWR keyword has not been used, the KRW keyword has the effect of scaling the relative permeability value calculated from the appropriate saturation table after the scaled saturation end points have been accounted for. Hence:

[EQ 6.31]

The relative permeability is taken to be the value at either the maximum saturation of the saturation table or at SWU if this has been specified.

If the KRWR keyword has been used, then the scaling honors the Kr at the critical saturation (SR) of the displacing phase. When the alternative scaling method using three saturation nodes is invoked by keyword SCALECRS, SR is given by

SR = 1 - SOWCR - SGL in gas/oil or gas/oil/water runs

SR = 1 - SGCR in gas/water runs

where SOWCR and SGCR are the scaled values. When the alternative scaling method is not employed, only the two nodes SWCR and SWU are used to scale the saturation end points, and SR is taken to be the transformed value of or

.


[EQ 6.32]

[EQ 6.33]

Two keywords are provided to allow the maximum water relative permeability to be set for each grid cell independently. These keywords are:

KRW Max water Kr for the non-directional saturation function tables

KRWR Kr at residual for the non-directional saturation function tables

None of the KRW keywords should be used if water is not present in the model. The keyword ENDSCALE should also be specified in the RUNSPEC section.

Each KRW keyword should be followed by one real number for each grid block in the current input box, specifying the maximum water relative permeability value. The data must be terminated by a slash(/).



SPECIALx FRONTSIM

RUNSPECGRIDEDIT

x PROPSREGIONSSOLUTIONSUMMARYSCHEDULE Krw Krw Table( )KRW GridBlock( )

Krwmax Table( )-------------------------------------------=

SR Table( ) 1.0 Sowcr Table( ) Sgco Table( )––=

SR Table( ) 1.0 Sgcr Table( )–=

SW SR< Krw Krw Table( )KRWR GridBlock( )Krw SR( ) Table( )

-----------------------------------------------=

SW SR> Krw KRWR KRW KRWR–Krwmax Krw SR( )–------------------------------------------- Krw Table( ) Krw SR( )–( )+=

204 Keywords FrontSim User GuideKRWR

If any of the KRW* keywords are omitted in a model where they could be accepted, then the maximum water Kr value defaults to the value used in the appropriate water saturation function table.

If pure normalized curves are used where (1.0-SOWCR-SGL) is equals to SWU, then depending on the Scaling option used (see the SCALECRS keyword) the two end-points may be equal. If this is the case both KRW and KRWR apply to the same point.and the KRWR keyword is ignored.

ECLIPSE 100 See also keywords SWU and ENKRVD in the PROPS section.


Example

-- In the RUNSPEC section :DIMENS1 7 3 /ENDSCALE/-- In the PROPS section :-------- IX1-IX2 JY1-JY2 KZ1-KZ2BOX

1 1 2 7 1 3KRWR6*0.556*0.656*0.67 /

FrontSim User Guide KeywordsMAPAXES

205

MMAPAXES Input of pre-processor map origin

This keyword is entirely optional.

It is normally output by grid pre-processors (such as the GRID program) so that the origin of the maps used to generate the grid can be stored. The origin will then be available via the Grid file for post-processing.

Following the keyword line, there is a single record containing six items of data, ending with a slash (/):

X1, Y1 The X and Y coordinates of one point of the grid Y-axis relative to the map

X2, Y2 The X and Y coordinates of the grid origin relative to the map origin

X3, Y3 The X and Y coordinates of one point of the grid X-axis relative to the map

Figure 6.4 Meanings of the MAPAXES keyword entries

Note Within the GRID program the length of the vectors (X2,Y2), (X1,Y1) and (X2,Y2),(X3,Y3) should be the same.

See also the MAPUNITS keyword.

Example


SPECIALx FRONTSIM

RUNSPECx GRID


MAPAXES0.0 100.0 0.0 0.0 100.0 0.0 /

206 Keywords FrontSim User GuideMAPUNITS

MAPUNITS Specifies units used for MAPAXES dataThis keyword is entirely optional.

It is normally output by grid pre-processors, such as the GRID program.

The MAPUNITS keyword defines the units used for the MAPAXES data, which defines the simulation grid position with respect to maps.

Following the keyword line, there is a single record containing one item of data, ending with a slash (/).

Note Use the European spelling METRES: the US spelling METERS is not recognized.

ExampleThe units will then be available via the GRID file for post-processing.

See also the MAPAXES keyword.


SPECIALx FRONTSIM

RUNSPECx GRID


MAPUNITSMETRES /

FrontSim User Guide KeywordsMAXSTEP

207

MAXSTEP Sets a maximum value for subsequent timestepsThe keyword is used to declare a maximum possible value for all subsequent timesteps, until the value is changed by applying this keyword again with a different value.

The keyword should be followed by a line containing one item of data, terminated by a slash (/):

Item 1:The maximum length of the next timestep.

• UNITS: days

• DEFAULT: The default value depends on the run mode.

Incompressible 2-phase: 1825 days

Compressible 2-phase: 730 days

3-phase black oil: 90 days

Compositional: 30 days

Typically, this keyword may be used to force short timesteps to reduce the danger of a convergence failure.

See also NEXTSTEP.

Example



x SCHEDULE

MAXSTEP1 /

208 Keywords FrontSim User GuideMETRIC

METRIC Metric units are to be used This indicates that metric units are to be used. Note that this is the default unit convention.

See also the FIELD keyword.





FrontSim User Guide KeywordsMINPV

209

MINPV Sets a minimum pore volume a cell must have to be activeThe keyword is used to declare a threshold pore volume which a cell must exceed or it is made inactive.

The keyword should be followed by a single positive real number, the minimum pore volume of an active cell, in the current units.

• UNITS: METRIC: rm3,FIELD: rb

• DEFAULT: 0.000001 (all unit sets)


The keyword causes any cell with a pore volume less than the input value to become inactive.

An inactive cell does not contribute to the total volume of the system, and is treated by default as a barrier.

Cells that have been set inactive using the ACTNUM keyword remain so even if their pore volume exceeds the threshold; using MINPV only affects active cells.

In the absence of MINPV, the default minimum pore volume is 1.0E-6 (in the current units).

Example


SPECIALx FRONTSIM

RUNSPECx GRID


MINPV4500 /

210 Keywords FrontSim User GuideMINSTEP

MINSTEP Sets a minimum value for subsequent timestepsThe MINSTEP keyword sets a minimum value for subsequent timesteps.

The keyword is used to declare a minimum possible value for all subsequent timesteps, until the value is changed by applying MINSTEP again with a different value. The keyword should be followed by a line containing one item of data, terminated by a slash (/).

• UNITS: Days (FIELD), Days (METRIC)

• DEFAULT: 1 Day

Example



x SCHEDULE

MINSTEP1 /

FrontSim User Guide KeywordsMISUPPLY

211

MISUPPLY Solvent supply rateDescribes field IOR solvent supply limit.

MISUPPLY has one argument, terminated by a slash (/).

MIRATE: Available solvent supply rate for field.


• DEFAULT: None

Example



x SCHEDULE

MISUPPLY-- MIRATE

5.0e3/

212 Keywords FrontSim User GuideMSGFILE

MSGFILE Generate an XML-formatted message fileThis keyword generate a XML formatted ascii -file (.msg) containing all messages, warnings, errors etc. from the simulation run.


1 <flag>

0 = OFF

1 = ON

• DEFAULT: ON

Example


x FRONTSIMx RUNSPEC


MSGFILE0/

FrontSim User Guide KeywordsMULTFLT

213

MULTFLT Modifies the transmissibility across a named faultThe MULTFLT keyword can be used to modify the transmissibility across a fault previously defined using the FAULTS keyword.

The keyword is followed by any number of records, each containing the following items of data, and each terminated with a slash (/):

1 Fault name (as specified in the FAULTS keyword)

2 Transmissibility multiplier

• DEFAULT: 1.0

The set of records must end with a blank record containing only a slash (/).

Notes• If a fault is referred to twice in one or more MULTFLT keywords, the transmissibility

multiplier is taken from the last entry.

• If the MULTX, MULTY, MULTZ, MULTX-, MULTY-, or MULTZ- keywords are used for some cells, in addition to the MULTFLT keyword, then the resultant transmissibility multiplier is the product of the two input multipliers.

• Transmissibility modifications made with MULTFLT are shown in the output TRANX, TRANY, TRANZ arrays in the INIT file, but not in the output MULTX, MULTY, MULTZ arrays.

• MULTFLT modifications apply both to normal and non-neighbor connections.

• If two faults with different names run along the same face of a cell, then both transmissibility multipliers are applied.

• See also the FAULTS keywords.

ExampleRefer to the FAULTS keyword example:


SPECIALx FRONTSIM

RUNSPECx GRIDx EDIT

PROPSREGIONSSOLUTIONSUMMARYSCHEDULE

MULTFLT-- Multiplierzigzag 0.2 /block 1.4 //

214 Keywords FrontSim User GuideMULTIPLY

MULTIPLY Multiply array by a constant in current boxThe keyword may be followed by any number of records, each of which is terminated by a slash (/). The data is terminated by a null record (that is, a record with no data before the terminating slash(/)).



2 The constant by which the array, specified by item 1, is to be multiplied

The constant should not be negative, but may be real or integer.

Items 3-8 define the limits of a box within the grid over which the value is to be set.

These items may be used to re-define the input box for this and subsequent operations within the current keyword. The values are used until reset or until the end of the keyword.










1 ≤ IX1 ≤ IX2 ≤ NDX

1 ≤ JY1 ≤ JY2 ≤ NDY

1 ≤ KZ1 ≤ KZ2 ≤ NDZ,


See also keywords BOX, ENDBOX, EQUALS, ADD and COPY.

Notes• The multiplied quantity may be less than unity, in order to divide.

• The use of the MULTIPLY keyword assumes that a value has already been assigned to the array, either explicitly, or using the EQUALS keyword.

• The ADD, COPY, EQUALS and MULTIPLY keywords are processed as they are read, so that repeated operations are possible.


SPECIALx FRONTSIM

RUNSPECx GRIDx EDITx PROPS

REGIONSSOLUTIONSUMMARYSCHEDULE

FrontSim User Guide KeywordsMULTIPLY

215

Examples



-------- ARRAY CONSTANT ----- BOX -----MULTIPLY

TRANX 500 3 8 1 10 3 3 /TRANZ 0 / defaults to last specified boxPORV 100.0 / defaults to last specified box

/

-------- ARRAY CONSTANT ----- BOX -----MULTIPLY

PERMX 0.1 3 8 1 10 3 3 /PERMZ 0 / defaults to last specified boxPORO 0.2 / defaults to last specified box

/

216 Keywords FrontSim User GuideMULTNUM

MULTNUM Defines regions for applying inter-region transmissibility multipliersThe MULTNUM keyword provides an alternative region definition for applying inter-region transmissibility multipliers using the keyword MULTREGT, instead of applying them to flux regions defined by FLUXNUM.

The MULTNUM keyword should be followed by one integer for each grid cell, specifying the region number to which it belongs. The data must be terminated by a slash (/).

Any cells not explicitly assigned a value of MULTNUM will be taken to be in region 1.

ECLIPSE 100 The MULTNUM array can be copied into the REGIONS section arrays (FIPNUM, PVTNUM, etc.) using the COPY keyword.

ExampleTo define 9 separate regions in a 4*4*3 field (with the maximum number of MULTNUM regions set equal to 9):


SPECIALx FRONTSIM

RUNSPECx GRID


MULTNUM1 1 2 21 1 2 23 3 3 34 4 4 45 5 5 56 7 8 86 7 8 86 7 8 816*9 /

FrontSim User Guide KeywordsMULTPV

217

MULTPV Pore volume multipliersThe keyword should be followed by one non-negative real number for every grid block in the current input BOX. The values specified act as multipliers on the pore volumes calculated by FrontSim for each grid block. The data must be terminated by a slash (/).

Any MULTPV values that are not specified when the end of the GRID section is reached, default to 1.0.


Use in the EDIT sectionIf MULTPV is entered in the EDIT section, it acts as an additional multiplier on the pore volumes after any edited pore volumes have been read from the EDIT section.

Note Use of MULTPV in the EDIT section is not recommended in general, except as modifiers to values of PORV entered explicitly in the EDIT section.

MULTPV should normally be specified in the GRID section rather than in the EDIT section.

Example


SPECIALx FRONTSIM

RUNSPECx GRIDx EDIT

PROPSREGIONSSOLUTIONSUMMARYSCHEDULE


5 6 3 8 4 6 /MULTPV36*1.25 /

218 Keywords FrontSim User GuideMULTREGT

MULTREGT Multiplies the transmissibility between flux or MULTNUM regionsThe MULTREGT keyword can be used to set a transmissibility multiplier between regions. The regions must previously have been defined using keyword FLUXNUM or MULTNUM in the GRID section.

MULTREGT applies to transmissibilities between MULTNUM regions.

If MULTNUM is not entered, then MULTREGT applies to transmissibilities between flux regions defined using FLUXNUM.

The MULTREGT keyword is followed by any number of data records. Each record contains the following five items of data, and is terminated with a slash (/).

1 From region number (I): A non-positive or defaulted value acts as a wildcard on all regions.

• DEFAULT: Negative

2 To region number (J): A non-positive or defaulted value acts as a wildcard on all regions.


3 Transmissibility multiplier for all transmissibilities connecting regions I and J

4 Direction(s) in which to apply the multiplier:

Either X, Y, Z, XY, YZ, XZ or XYZ.

• DEFAULT: XYZ

5 Flag governing application of multiplier to non-neighbor connections:

NNC: Apply the transmissibility multiplier only to non-neighbor connections between regions I and J

NONNC: Do not apply the transmissibility multiplier to any non-neighbor connections between regions I and J

ALL: Apply the transmissibility multiplier to all connections between regions I and J

NOAQUNNC: Do not apply the transmissibility multiplier to numerical aquifer connections.

• DEFAULT: ALL

The set of records must end with a blank record containing only a slash (/).ECLIPSE 100 When using MULTREGT in the SCHEDULE section, only the first three items should be

specified; the remaining items assume values specified in the GRID section or defaulted. The effect of using MULTREGT in the SCHEDULE section is cumulative. Hence if MULTREGT is specified twice for the same connection between regions, the product of the transmissibility multipliers is used.

The effect of MULTREGT in the GRID section is not cumulative.

Notes• The multipliers specified in the MULTREGT keyword are applied after accounting for any

values of MULTX, MULTY, MULTZ, or MULTFLT entered in either the GRID or EDIT sections.


SPECIALx FRONTSIM

RUNSPECx GRIDx EDIT

PROPSREGIONSSOLUTIONSUMMARY

x SCHEDULE

FrontSim User Guide KeywordsMULTREGT

219

• Similarly, the multipliers specified in this keyword are applied after accounting for any values of MULTX-, MULTY- or MULTZ-.

• If either region number I or J is set nonpositive or defaulted, then that region identifier is taken as a wildcard and the multiplier is applied between all regions I and J, with , matching the template.

• If the region numbers I and J are equal and positive, then the transmissibilities within that region in the specified direction(s) are multiplied by the given value, as well as any transmissibilities connecting any other regions.

• The keyword does not affect the non-neighbor connections between matrix and fracture blocks in a dual porosity simulation.

• Non-neighbor connections arising from numerical aquifer connections to the grid are modified by MULTREGT unless the NOAQUNNC flag is set in item 5.

ECLIPSE 100 • If the pair of region numbers I and J are specified twice, then the later multiplier is applied between the regions; the multipliers are not cumulative.

ECLIPSE 100 • This facility can be used to modify connections between PVT regions by assigning FLUXNUM or MULTNUM in the GRID section equal to the PVT regions, and then COPYing FLUXNUM or MULTNUM to PVTNUM in the REGIONS section.

• In order to use MULTREGT in the EDIT section, TRANX, TRANY, TRANZ values should also be specified in the EDIT section. If the transmissibility values are not specified, a warning message will be produced.

Example

I J≠

MULTREGT--'From' region 'To' region Transmissibility Directions NNCs

multiplier

1 2 0.5 /1 3 0.0 /4 4 0.4 'XY' /5 1* 0.75 / Between region 5 and a

ny region./

220 Keywords FrontSim User GuideMULTX

MULTX Transmissibility multipliers in X-directionThe keyword should be followed by one non-negative real number for every grid block in the current input box. The data must be terminated by a slash (/).

The MULTX values specified act as multipliers on the transmissibilities calculated by the program for the +X face of each grid block or specified directly using TRANX in the EDIT section.

Thus, a value of MULTX specified for block (I, J, K) multiplies the transmissibility between blocks (I, J, K) and (I+1, J, K)


Note Transmissibility multipliers specified by the MULTX, MULTY and MULTZ keywords affect non-neighbor connections as well as normal connections.

ExampleThis example multiplies the transmissibility values in a box by 0.2.


SPECIALx FRONTSIM

RUNSPECx GRID



5 5 3 8 4 6 /MULTX18*0.2 /ENDBOX

FrontSim User Guide KeywordsMULTX-

221

MULTX- Transmissibility multipliers in the negative X-directionThe keyword should be followed by one non-negative real number for every grid block in the current input box. The data must be terminated by a slash (/).

The MULTX- values specified act as multipliers on the transmissibilities calculated by the program for the -X face of each grid block or specified directly using TRANX in the EDIT section.

Thus, a value of MULTX- specified for block (I, J, K) multiplies the transmissibility between blocks (I, J, K) and (I-1, J, K)


If both the MULTX keyword and MULTX- are specified, then the product is used. For example, if MULTX is specified for the block (I, J, K) and MULTX- is specified for the block (I+1, J, K), then the program uses the product of the nominated MULTX and MULTX- values to multiply the calculated transmissibility between the two adjacent blocks.

Note Transmissibility multipliers specified by the MULTX, MULTY, MULTZ keywords affect non-neighbor connections as well as normal connections.

Example


SPECIALx FRONTSIM

RUNSPECx GRID



5 5 3 8 4 6 /MULTX-18*0 /ENDBOX

222 Keywords FrontSim User GuideMULTY

MULTY Transmissibility multipliers in Y-directionThe keyword should be followed by one non-negative real number for every grid block in the current input box. The data must be terminated by a slash (/).

The MULTY values specified act as multipliers on the transmissibilities calculated by the program for the +Y face of each grid block or specified directly using TRANY in the EDIT section.

Thus, a value of MULTY specified for block (I, J, K) multiplies the transmissibility between blocks (I, J, K) and (I, J+1, K)



ExampleThis example multiplies the transmissibility values in a box by zero.


SPECIALx FRONTSIM

RUNSPECx GRID



5 5 3 8 4 6 /MULTY

18*0.0 /

ENDBOX

FrontSim User Guide KeywordsMULTY-

223

MULTY- Transmissibility multipliers in the negative Y-directionThe keyword should be followed by one non-negative real number for every grid block in the current input box. The data must be terminated by a slash (/).

The MULTY- values specified act as multipliers on the transmissibilities calculated by the program for the +Y face of each grid block or specified directly using TRANY in the EDIT section.

Thus, a value of MULTY- specified for block (I, J, K) multiplies the transmissibility between blocks (I, J, K) and (I, J-1, K)


If both the MULTY keyword and MULTY- are specified, then the product is used. For example, if MULTY is specified for the block (I, J, K) and MULTY- is specified for the block (I, J-1, K), then the program uses the product of the nominated MULTY and MULTY- values to multiply the calculated transmissibility between the two adjacent blocks.


Example


SPECIALx FRONTSIM

RUNSPECx GRID



5 5 3 8 4 6 /MULTY-

18*0 /ENDBOX

224 Keywords FrontSim User GuideMULTZ

MULTZ Transmissibility multipliers in Z-directionThe keyword should be followed by one non-negative real number for every grid block in the current input box. The data must be terminated by a slash (/).

The MULTZ values specified act as multipliers on the transmissibilities calculated by the program for the +Z face of each grid block or specified directly using TRANZ in the EDIT section.

Thus, a value of MULTZ specified for block (I, J, K) multiplies the transmissibility between blocks (I, J, K) and (I, J, K+1).



ExampleThis example multiplies the transmissibility values in a box by 1000.


SPECIALx FRONTSIM

RUNSPECx GRID



1 11 1 19 2 2 /MULTZ209*1000.0 /ENDBOX

FrontSim User Guide KeywordsMULTZ-

225

MULTZ- Transmissibility multipliers in the negative Z-directionThe keyword should be followed by one non-negative real number for every grid block in the current input box. The data must be terminated by a slash (/).

The MULTZ- values specified act as multipliers on the transmissibilities calculated by the program for the +Z face of each grid block or specified directly using TRANZ in the EDIT section.

Thus, a value of MULTZ- specified for block (I, J, K) multiplies the transmissibility between blocks (I, J, K) and (I, J, K-1).


If both the MULTZ keyword and MULTZ- are specified, then the product is used. For example, if MULTZ is specified for the block (I, J, K) and MULTZ- is specified for the block (I, J, K+1), then the program uses the product of the nominated MULTZ and MULTZ- values to multiply the calculated transmissibility between the two adjacent blocks.


ExampleThis example multiplies the transmissibility values in a box by 1000.


SPECIALx FRONTSIM

RUNSPECx GRID



1 11 1 19 2 2 /MULTZ-209*1000 /ENDBOX

226 Keywords FrontSim User GuideMW

MW Molecular weightsIn a run with components, this keyword associates a mean molecular weight with each component.

The keyword should be followed by values.


ExampleMolecular weights for a 4-component study:


SPECIALx FRONTSIM

RUNSPECGRIDEDIT


MW18 32 45.6 78.0 /

Nc

Nc

FrontSim User Guide KeywordsNEXTSTEP

227

NNEXTSTEP Sets a maximum value for the next timestep

The keyword is used to declare a maximum possible value for the next timestep.

The keyword should be followed by a line containing one item of data, terminated by a slash (/):

Item 1: The maximum length of the next timestep.

• UNITS: days.

• DEFAULT: Set to the same value as MAXSTEP, specified or defaulted.

Typically, this keyword may be used to force a short timestep immediately following a large well rate change, to reduce the danger of a convergence failure.

The keyword does not restrict the length of the subsequent timesteps following the next timestep.

See also MAXSTEP.

Example


SPECIALx FRONTSIM


x SCHEDULE

NEXTSTEP1 /

228 Keywords FrontSim User GuideNODPPM

NODPPM No dual porosity permeability multiplierIn a dual porosity run (keyword DUALPORO in the RUNSPEC section) the permeability values for the fracture cells are normally multiplied by the fracture porosity to yield a net bulk fracture permeability.

If the NODPPM keyword is used this operation is suppressed, so that you must enter net bulk permeability values directly.

This keyword has no associated data.


SPECIALx FRONTSIMx RUNSPECx GRID


FrontSim User Guide KeywordsNOGRAV

229

NOGRAV Sets gravity to zeroKeyword NOGRAV sets the gravity vector to zero. It takes no arguments. This will affect both the pressure solver and the saturation solver.ECLIPSE 100

ECLIPSE 300SPECIAL

x FRONTSIMx RUNSPEC


230 Keywords FrontSim User GuideNOSIM

NOSIM Turn off simulationThis keyword stops simulation after initializing the model and reporting initial fluids in place, but the simulator will continue reading and checking the data. This is intended primarily to verify the validity of the keyword syntax prior to submitting a large simulation run.

If the NOSIM keyword is present in the RUNSPEC section, a datacheck license will be used if available, otherwise a FrontSim license. If NOSIM is not present, a full FrontSim license is required.

If the NOSIM keyword is present in the SCHEDULE section, FrontSim will continue reading and perform checking of input data until the end of the section, but the simulation will only continue until the NOSIM keyword is specified.




GRIDEDITPROPSREGIONSSOLUTIONSUMMARY

x SCHEDULE

FrontSim User Guide KeywordsNTG

231

NTG Net to gross thickness ratiosThe keyword should be followed by one non-negative real number for every grid block in the current input box. The values specified are used to convert from gross to net thicknesses, and act as multipliers of grid block pore volumes and transmissibilities in the X and Y directions. The data must be terminated by a slash (/).

Any NTG values that are not specified when the end of the GRID section is reached default to 1.0.

Grid blocks whose pore volume is zero are treated as inactive.


Example


SPECIALx FRONTSIM

RUNSPECx GRID



6 11 4 9 2 3 /NTG6*0.4 6*0.4 6*0.48 6*0.51 6*0.7 6*0.726*0.4 6*0.4 6*0.48 6*0.51 6*0.7 6*0.72 /

232 Keywords FrontSim User GuideNTRNSAVE

NTRNSAVE Turns off saving transmissibilities in memoryWhen switched on, this option saves the transmissibilities in memory, and thereby avoids recalculating transmissibilities at each time step. This usually increases the simulation speed. It also increases dynamic memory usage by FrontSim.

When keyword NTRNSAVE is used it turns this option off.



x FRONTSIMRUNSPEC


FrontSim User Guide KeywordsNXFIN

233

NXFIN Number of local cells in each global cell of an LGR in X direction If a local grid refinement covers more than one global cell in the x-direction, NXFIN can be used to dictate how many local cells each of the global cells is divided into. The keyword should be placed after the keyword CARFIN introducing the local grid, and before the local grid is terminated with ENDFIN.

NXFIN should be followed by I2-I1+1 values terminated with a slash (/), where I1 and I2 are the I-coordinates defining the box of global grid cells to be refined (items 2 and 3 in keyword CARFIN). The number of values is thus the number of global cells of the refinement counted along the X-direction. The values represent the number of local cell divisions, counted along the X-direction, in each of the global cells. The sum of the values must, of course, be equal to NX set in item 8 of CARFIN.

In the absence of this keyword, the global cells are refined to contain equal numbers of local cells in the x-direction.

Example


RUNSPECx GRID


CARFIN-- NAME I1 I2 J1 J2 K1 K2 NX NY NZ

LGR2 3 4 1 2 5 6 4 2 4 /--Two global cells in x-direction to become 4 local cells--with three local cells in first global, 1 in secondNXFIN3 1 /

234 Keywords FrontSim User GuideNYFIN

NYFIN Number of local cells in each global cell of an LGR in Y directionIf a local grid refinement covers more than one global cell in the y-direction, NYFIN can be used to dictate how many local cells each of the global cells is divided into. The keyword should be placed after the keyword CARFIN introducing the local grid, and before the local grid is terminated with ENDFIN.

NYFIN should be followed by J2-J1+1 values terminated with a slash (/), where J1 and J2 are the J-coordinates defining the box of global grid cells to be refined (items 4 and 5 in keyword CARFIN). The number of values is thus the number of global cells of the refinement counted along the Y-direction. The values represent the number of local cell divisions, counted along the Y-direction, in each of the global cells. The sum of the values must, of course, be equal to NY set in item 9 of CARFIN.

In the absence of this keyword, the global cells are refined to contain equal numbers of local cells in the y-direction.

The form of the input is analogous to that of NXFIN.


RUNSPECx GRID


FrontSim User Guide KeywordsNZFIN

235

NZFIN Number of local cells in each global cell of an LGR in Z directionIf a local grid refinement covers more than one global cell in the x-direction, NZFIN can be used to dictate how many local cells each of the global cells is divided into. The keyword should be placed after the keyword CARFIN introducing the local grid, and before the local grid is terminated with ENDFIN.

NZFIN should be followed by K2-K1+1 values terminated with a slash (/), where K1 and K2 are the K-coordinates defining the box of global grid cells to be refined (items 6 and 7 in keyword CARFIN). The number of values is thus the number of global cells of the refinement counted along the Z-direction. The values represent the number of local cell divisions, counted along the Z-direction, in each of the global cells. The sum of the values must, of course, be equal to NZ set in item 10 of CARFIN.

In the absence of this keyword, the global cells are refined to contain equal numbers of local cells in the y-direction.

The form of the input is analogous to that of NXFIN.


RUNSPECx GRID


236 Keywords FrontSim User GuideOIL

OOIL Indicates that the run contains oil

This keyword indicates that a run contains an oil phase. It should be specified whenever an oil phase exists or could exist.

The keyword OIL takes no arguments.




FrontSim User Guide KeywordsOMEGAA

237

OMEGAA Overrides default Ωa valuesIn compositional runs, the program supplies a default value of the equation of state coefficient. However, should you wish to modify this value, the OMEGAA keyword may be used. Note that only small variations around the default value are advisable. A separate value may be specified for each component.


• DEFAULT: Peng-Robinson: 0.457235529, RK, SRK and ZJ: 0.4274802

Example


SPECIALx FRONTSIM

RUNSPECGRIDEDIT


OMEGAA4*0.457 3*0.461 0.462 /

Ωa

238 Keywords FrontSim User GuideOMEGAB

OMEGAB Overrides default Ωb valuesIn compositional runs, the program supplies a default value of the equation of state coefficient. However, as in the case of , this keyword enables you to modify the value of this coefficient. As for , only a small variation is advisable. A separate value may be specified for each component.


• DEFAULT: Peng-Robinson: 0.077796074, RK, SRK and ZJ: 0.08664035

Example


SPECIALx FRONTSIM

RUNSPECGRIDEDIT


OMEGAB0.0777 2*0.078 0.07677 /

Ωb

Ωa

Ωa

FrontSim User Guide KeywordsOPTIONFS

239

OPTIONFS Activates special program optionsThe OPTIONFS keyword can be used to activate special options within particular facilities in FrontSim. These options are mainly of a temporary or experimental nature, or act to restore back-compatibility with earlier versions of the code.

The keyword should be followed by up to 20 integers, each of which activates a special option within particular FrontSim facilities.

• A value equal to zero switches off the special option.

• A value other than zero activates a special option.

If fewer than 20 integers are read, the remainder are left unchanged. Note that repeat counts (for example 3*0) can be used if required (there must be no spaces before or after the asterisk).

The data field should be terminated by a slash (/).

Control1 Material balance reporting option

0: (VIIP-CVF-VIP)/(PV/Bvi) where v is Water, Oil or Gas. This represents the present phase error at initial reservoir volume conditions divided by the initial reservoir pore volume

1: (VIIP-CVF-VIP)/VIP where V is oil, water or gas. This is the pre-2002A Frontsim behavior.

2: (VIIP-CVF-VIP)*Dv/(OIIP*Do+WIIP*Dw+GIIP*Dg) where v is Water, Oil or Gas, and D is density. This represents the present phase mass error divided by the total initial fluid mass.

• DEFAULT: 0

2 Stairplots in summary files

The resulting properties that are only calculated once during the timestep (specified on input by the DATES/TSTEP keywords) are now only written once at the end of the step. The other values at all other points are written as undefined values. This is for compatibility with ECLIPSE Office.

Note Note that undefined values are represented by a very large negative number, which may cause the scale to be set incorrectly in other plotting programs such as GRAF, GridSim or Excel.

0: Behavior as described above

1: Behavior as in previous releases.

• DEFAULT: 0

3 Shifting of values on summary files

Production rates, etc., are written out every mini-timestep as an average value through the timestep. This is now written in the end of this small timestep instead of in the middle as before. This is for compatibility with ECLIPSE.

0: Behavior as described above


x FRONTSIMx RUNSPEC

GRIDEDITPROPSREGIONSSOLUTIONSUMMARY

x SCHEDULE

240 Keywords FrontSim User GuideOPTIONFS

1: Behavior as in previous releases.

• DEFAULT: 0

4 This controls the way in which formation volume factor and viscosity values are interpolated/extrapolated within the 3-phase saturation solver.

0: Bo, Bg, Vo, Vg are interpolated/extrapolated linearly in 1/Bo, 1/Bg, 1/(BoVo) and 1/(BoVg) respectively

1: Bo, Bg, Vo, Vg are extrapolated linearly.

• DEFAULT: 0

5 When used with 3-phase data sets, this flag modifies the way in which well terms are calculated internally within the saturation solver. The 3-phase saturation solver calculation used is part of the ECLIPSE 300 code. This flag disables the well cross-flow calculation. In most cases this should have no effect; however, in some data sets it can remove problems associated with table extrapolations.

0: Cross flow disabled

1: Cross flow enabled, as in previous releases.

6 When set to 1 FrontSim will not override the pressure recalculation frequency set by the user (see TUNEFSPR).

• DEFAULT: 0.

7 This flag changes the way in which the pressure and saturation are adjusted during the mappings between the streamlines and the grid. These adjustments are required to ensure that the fluid in the cell exactly fills the pore volume.

0: The pressure is modified so that the surface volumes in each cell are honoured (the new mass conserving pressure mapping).

1: The pressure is chosen using the method specified in TUNEFS1D. The volume of hydrocarbon is then adjusted so that the fluids exactly fill the volume. (This is the old pressure mapping).

2: Gives the new mapping when mapping from FrontSim to ECLIPSE 300 and the old when mapping from ECLIPSE 300 to FrontSim.

3: Gives the old mapping when mapping from FrontSim to ECLIPSE 300 and the new when mapping from ECLIPSE 300 to FrontSim.

• DEFAULT: 0

8 The default reference depth set by the WELSPECS keyword is set equal to the center depth of the grid block containing the top-most connection in the well. In previous releases it was set to the top depth of the grid block.

0: Reference depth = center depth of grid block

1: Reference depth = top depth of grid block, as in previous releases.

• DEFAULT: 0

9 This item has been replaced by item 8 of TUNEFS1D.

10 Reserved for 3-phase debug information.

11 A value of 1 turns ON the Appleyard Chop in the saturation solver.

• DEFAULT: 0

12 This item has been replaced by item 12 of TUNEFS1D.


241

13 This alters the way that well rates are matched between the pressure and saturation solvers [for 3-phase and compositional cases].

0: The rates are adjusted individually on the streamlines prior to solving for saturation.

1: The total rates are adjusted for all the streamlines after solving for saturation. The previous behavior can cause high material balance errors, and is not recommended.

• DEFAULT: 0

14 Average pressure reporting.

If set to 1 the average pressures reported by FrontSim will be PV weighted instead of HCPV weighted.

If the field or region is 100% water a PV-weighted average is used for that region, even if this option is defaulted to HCPV-weighted average.

• Default = 0 (HCPV weighted)

15 Reserved for future use.

16 If set to 1, FrontSim will report Non-Neighbor Connections (NNCs) to the .PRT file. RPTSCHED needs to be set to get NNC report

• DEFAULT: 0

17 When set to 1 FrontSim will revert back to previous behavior on the BHP limit set for the wells in 3 phase.

0: To prevent un-physical extrapolations in the PVT table lookups, the BHP limit for injectors is set to the minimum of the user-specified BHP limit and 1.2 times the maximum pressure supplied in the PVT lookup tables. This limit is checked against the grid cell pressure calculated by the pressure solver for the actual well connection to prevent it from being less than the grid cell pressure. A similar approach is used for the producers on the streamlines with 80% of the minimum pressure in the PVT lookup tables as minimum limit.

1: The previous behavior was to not apply any BHP limit to the saturation solver.

• DEFAULT: 0

18 This item only affects 3-phase runs. When set to 1, FrontSim will allow more than one iteration on gravity segregation using the first parameter of TUNEFSSA (SegIT).

0: FrontSim will force the gravity segregation iterations to be a maximum of 1 for 3-phase models.

1: Allows SegIT>1./ This can lead to larger material balance errors and in some cases non-convergence in the pressure solver, and is therefore not recommended.

• DEFAULT: 0


20 This option controls the ordering of injectors for initial solvent allocation using keyword RANKWELL for the IOR Scale Up option.

0: uses the order the wells as specified under keyword RANKWELL.

1: FrontSim reverts to previous behavior and eligible wells are ordered alphabetically.

• DEFAULT: 0

21 When set to 1 FrontSim assigns the field/group rates among the wells in proportion with their productivity indices (see GUIDERAT).



23 When set to 0, FrontSim will duplicate all front positions written to the SLN file. This overcomes a plotting feature in FloViz/AVS that smears all the saturation fronts by linearly interpolating the assigned nodal colors. If set to 1, the streamline visualization should be restored to that produced using the old B-files.

• DEFAULT: 0

24 This switch modifies the RS and RV values set during Equilibration when RSVD, PBVD, RVVD and PDVD are omitted. See also items 7 and 8 of EQUIL.

0: This sets the RS throughout the oil zone to the saturated RS value at the gas oil contact pressure and the RV throughout the gas zone to the saturated RV value at the gas oil contact pressure. This is the same behavior as in ECLIPSE.

1: This sets the RS in the oil zone to the saturated RS at the pressure in the grid block and the RV in the gas zone to the saturated RV at the pressure of the grid block. This is the pre-2003 behavior for FrontSim.

• DEFAULT: 0


26 This enables additional diagnostic information from the 3-phase saturation solver


28 This switch provides back-compatibility (pre-2004A) for the way source and sink terms are handled in the 3-phase Saturation solver. In the rare cases when the pressures in streamlines in the injection or producers become unacceptably large or small, we either stop injecting or producing fluids. Previously we limited the flow based on the cell pressure. This is however more expensive in computational terms.

0: Stops injection or production on individual stream lines if the cell pressure becomes unacceptably large or small.

1: Alters injection and production on individual stream lines if the cell pressure becomes too large or small so as to restrict the pressure to acceptable values.

• DEFAULT: 0

29 This restores the previous method (pre-2004A) of carrying out equilibration.

0: New ECLIPSE type method of equilibration, if allowed.

1: Old equilibration method.

• DEFAULT: 0



32 If this is set, the production rate used for determining injection rate under GCONINJE item 3, VREP, is always the field rate, not the rate of the group. This is pre-2004A behavior for FrontSim and different from ECLIPSE.


34 Activate listing cell numbers and its IJK index for the wrapped cells, or redundant cells defined in the grid. This should allow further user debugging, with an option to output this cell in Microsoft Excel format.

35 Activate the automatic streamline density calculation algorithm to compute an optimal streamline density for each time step. Computed densities override the StreamDens defined by item 2 of the TUNEFSSA keyword.

0: No tuning of streamline density is performed.


243

1: Method 1 - Does not require streamlines to be saved.

2: Method 2 - Requires streamlines to be saved using TUNEFSSA parameter 6

Both methods turn off the check of grid cells to add lines. However, method 2 does add further lines based on low flux cells. CPU time and memory usage for method 1 and 2 can be case dependent.


37 Allows the model to be initialized using capillary pressure and applies endpoint scaling to the relperm data to stabilize the initial solution. This will result in an initial solution that is in hydrostatic equilibrium above the depth at which Pcow=0.

1: The value of SWCR will be set to the initial water saturation above the OWC

0: The value of SWCR is not altered

• DEFAULT: 0

38 For 2005A an improved well target calculation algorithm has been implemented that should improve estimates of changes in phase rates during timestep.

If this parameter is set to 1, FrontSim will revert to pre-2005A behavior.

• DEFAULT: 0

39 0,1: Activates the new tuning of the AMG solver.

2: Set to 2 for backward compatibility for the tuning of the AMG linear solver.

The new tuning is generally faster with fewer linear iterations.


41 1: Generates an RSM report in XML format in a .XML file

2: Generates an RSM report in Excel format in a .RSM file

3: Generates an RSM report in ECLIPSE format in a .RSM file



44 Controls the way in which user-specified BHP pressure limits are applied to wells

0: Honors the BHP limits specified by the user.

1: The value of the BHP limit for a producer is restricted to be above the minimum pressure specified in the PVT table for the cell containing the first connection. The value of the BHP limit for an injector is restricted to be below the maximum pressure specified in the PVT table for the cell containing the first connection.

2: Turns off the warning messages about the restriction above.

3: Warnings are printed for all wells which have had their BHP changed

• DEFAULT: 0

45 1: Filter out all vector in summary files that start with W (WOPR, etc.) to reduce the size of the summary files.

2: Filter out all vectors that are not rates and BHP properties, to reduce the size of the summary files






50 Backward compatibility switch for pressure equation

For FrontSim 2006.1 a change was made to the implementation of the pressure equation in FrontSim. This switch was made to have a backward compatibility option for this change. Normally this option should not be turned on. However, if the user observes different results with FrontSim 2006.1 compared to previous releases that is likely due to the pressure solver, this switch can be used to investigate the reason for the change.

0: New implementation of pressure equation

1: Previous implementation for backward compatibility

• DEFAULT: 0

51 Debug output for PFM

When set to 1FrontSim will print misc. debug output for PFM (Pattern Flood Management) to the .PRT file (efficiencies, rates etc.) for every time step the optimization is activated.

• DEFAULT: 0

52 Reserved for future use


54 Backward compatibility switch for the ability to open wells that are shut due to no flow at bhp limit.

• DEFAULT: 0



57 Backwards compatibility switch for not honouring injection rate limits when under Pattern Flood Management (PFM) control. When this switch is different from zero - injection rate limits (both RATE and RESV) are not honored.


59 Backward compatibility switch for the change done to how the 1d EXPL solver handles the local time stepping when saturations are close to the critical saturation. When set to 1 FrontSim will revert back to pre-2008.1 behavior.

60 Backward compatibility switch for the reports based on the RPTALLOC keyword. From 2008.2 these reports are based on the rates at reservoir conditions and the injection efficiency is not printed. To revert to the 2008.1 behavior set this to 1. This will not have any effect if NOOFM is set in RPTALLOC.

• DEFAULT: 0

61 Backward compatibility switch for how PFM (WCONPAT) treats lumped completions. From 2009.1 the default for the PFM algorithm is to use well bundles as the lowest level for the weighting functions to improve the injection efficiencies even if lumped completions have been supplied by the user. Further for 2009.1 you can turn on multizone treatment based on the lumped completion definitions (WCONPAT, parameter 9). In 2008.2 and previous releases the rates for lumped completions were accumulated to well level before solving for the pressure, this is not the case for 2009.1. By setting this parameter to 1 and the 9th parameter of WCONPAT to ON, 2009.1 should behave like 2008.2 in the case where lumped completions are supplied by the user.

• DEFAULT: 0


245

62 On some platforms (for example XP64) the multi Core Front Tracker shows decrease in performance (CPU Usage) compared with running on one core. If this switch is set to 1,- FrontSim will do the streamline tracing in parallel, but do the front tracking in serial mode.

• DEFAULT: 0



65 If set to 1. For some 3-phase models FrontSim has problems computing liquid targets when the gas phase is breaking through the well. To resolved this a down weighted gas mobility is used when computing the total reservoir mobility and the phase fractions. This is only done if the target is not gas (GRAT).

66 When this is set to 1, FrontSim will use LRAT (producers) and RATE (injectors) instead of RESV control when exporting PFM rates to the PFM_SCHED file.

Example

OPTIONFS1 52* 1/

246 Keywords FrontSim User GuidePARACHOR

PPARACHOR Component parachors

In a run with components, this keyword associates a parachor with each component. These need only be entered if surface tensions are to be calculated.



• UNITS: Dynes1/4 cm11/4 /moles

Example


SPECIALx FRONTSIM

RUNSPECGRIDEDIT


PARACHOR74.92 192.74 390.4 /

Nc

Nc

FrontSim User Guide KeywordsPBUB

247

PBUB Initial bubble point pressureThis keyword should only be used in a black oil run. The keyword should be followed by one real number for every grid block, specifying the initial bubble point pressure. The data field should be terminated by a slash (/).

• UNITS: barsa (METRIC), psia (FIELD).

Grid blocks are ordered with the X axis index cycling fastest (from 1 to NDIVIX), followed by the Y axis index (from 1 to NDIVIY), and finally the Z axis index (from 1 to NDIVIZ). Repeat counts may be used for repeated values (for example 115*2.893). Note that spaces must not be inserted on either side of the asterisk (*).

This keyword is an alternative to the RS keyword for defining the initial dissolved gas distribution in runs with enumerated initial conditions.

When using explicit initialization, you must ensure that the initial solution is stable and physically reasonable.

See also the keywords PRESSURE, RV, PDEW, SWAT and SGAS in the SOLUTION section.



SPECIALx FRONTSIM



PBUB48*304248*3063 /

248 Keywords FrontSim User GuidePBVD

PBVD Bubble point versus depth tables for equilibrationThe data comprises one or more tables of bubble point pressure versus depth, one for each equilibration region. Each table consists of 2 columns of data, and must be terminated by a slash (/).



• UNITS: m (METRIC), ft (FIELD).

Column 2: The corresponding values of the bubble point pressure (Pbub).

• UNITS: barsa (METRIC), psia (FIELD)).


This keyword is an alternative to the RSVD keyword, in which the dissolved gas-oil ratio is tabulated against depth for each equilibration region. See also keyword EQUIL.

ExampleWith NTEQUL=1 and NDRXVD ≥ 3:


SPECIALx FRONTSIM



PBVD7000 40008000 40209000 4045 /

FrontSim User Guide KeywordsPCRIT

249

PCRIT Critical pressuresIn a run with components, this keyword associates a critical pressure with each component.



• UNITS: METRIC: Barsa, FIELD: psia

ExampleFor a four-component system:


SPECIALx FRONTSIM

RUNSPECGRIDEDIT


PCRIT1050 1300 1500 1803 /

Nc

Nc

250 Keywords FrontSim User GuidePCW

PCW Scaled maximum water capillary pressuresThis keyword allows the maximum water-oil (or water-gas) capillary pressure to be scaled on a grid block by grid block basis. The keyword can only be used when the End Point Scaling option is active (keyword ENDSCALE in the RUNSPEC section).

The capillary pressure is given by:

[EQ 6.34]

where

Capillary pressure from the table

Maximum Pc in the table - at Sw = Swco, connate water

Maximum Pc from the PCW data.

The PCW keyword should be followed by one real number for each grid block in the current input box, specifying the maximum water capillary pressure value. The data must be terminated by a slash(/).


If the PCW keyword is omitted, the maximum water Pc value defaults to the value used in the appropriate water saturation function table.

See also keywords SWFN, SWOF and SWATINIT in the PROPS section.

ExampleWith ENDSCALE specified in RUNSPEC; NDIVIX=1, NDIVIY=7 and NDIVIZ=3:


SPECIALx FRONTSIM

RUNSPECGRIDEDIT


PCW6*78.06*20.06*150.0 /

Pc PctPCWPcm

-------------⎝ ⎠⎛ ⎞=

Pct

Pcm

PCW

FrontSim User Guide KeywordsPDEW

251

PDEW Initial dew point pressureThis keyword should only be used in a black oil run. The keyword should be followed by one real number for every grid block, specifying the initial vapor oil-gas ratio. The data field should be terminated by a slash (/).



This keyword is an alternative to the RV keyword for defining the initial vaporized oil distribution in runs with enumerated initial conditions.


See also the keywords PRESSURE, RS, PBUB, SWAT and SGAS in the SOLUTION section.



SPECIALx FRONTSIM



PDEW48*612348*6098 /

252 Keywords FrontSim User GuidePDVD

PDVD Dew point versus depth tables for equilibrationThe data comprises one or more tables of dew point pressure versus depth, one for each equilibration region.

Each table consists of 2 columns of data, and must be terminated by a slash (/).




Column 2: The corresponding values of the dew point pressure (Pdew).



This keyword is an alternative to the RVVD keyword, in which the vaporized oil-gas ratio is tabulated against depth for each equilibration region. See also keyword EQUIL.



SPECIALx FRONTSIM



PDVD7000 30008000 30209000 3045 /

FrontSim User Guide KeywordsPERFORM

253

PERFORM FrontSim performance tuningThis keyword is used to set various tuning parameters for FrontSim. The keyword should be followed by a list of boolean values. The list should be terminated by a slash (/).

1 Store flow functions for every time step

Boolean value YES/NO

DEFAULT: YES

2 Store fronts for every time step

Boolean value YES/NO

DEFAULT: NO

Example


x FRONTSIMx RUNSPEC


PERFORMNO /

254 Keywords FrontSim User GuidePERMX

PERMX Specifies X-permeability valuesThis keyword specifies the permeability values in the X-direction.

In FrontSim, off-diagonal (tensor) permeabilities can be specified by the similar keywords, PERMXY, PERMYX,PERMXZ, PERMZX, PERMYZ,PERMZY.

Note Note that there are physical restrictions to the use of such values: only positive definite symmetric tensors are allowed.

The keyword should be followed by one non-negative real number for every grid block in the current input box specifying the permeability. The data must be terminated by a slash (/).

• UNITS: METRIC: mD, FIELD: mD

Grid blocks are ordered with the X axis index cycling fastest, followed by the Y and Z axis indices. Repeat counts may be used for repeated values (for example 115*208.4). Note that spaces may not be inserted on either side of the asterisk.

Note This is not the permeability between a cell and its neighbor. The transmissibility between a cell and its neighbor involves the permeability values for both cells.

Example


SPECIALx FRONTSIM

RUNSPECx GRID



5 16 3 8 1 1 /PERMX100 1500 10*6090 1500 10*6080 1500 10*6570 1500 10*7060 1500 10*7550 1500 10*75 /

FrontSim User Guide KeywordsPERMXY/ZY

255

PERMXY/ZY Specifies off-diagonal tensor permeability coefficientsThe PERMXY, PERMYX, PERMXZ, PERMZX, PERMYZ and PERMZY keywords specify the off-diagonal components of the permeability tensor.

The diagonal terms are aliased: PERMXX to PERMX, PERMYY to PERMY and PERMZZ to PERMZ.

The keyword should be followed by one real number for every grid block in the current input box specifying the X-direction permeability. The data must be terminated by a slash (/).


Grid blocks are ordered with the X-axis index cycling fastest, followed by the Y and Z axis indices. Repeat counts may be used for repeated values (for example 115*208.4). Note that spaces must not be inserted on either side of the asterisk.

If not already set by FDM9PNT, the generalized finite difference method is used automatically when using tensor permeabilities.

Any tensor values not entered are defaulted to zero (0.0).

To transform the permeability tensor from local coordinates to the global coordinate system the GADJUST keyword should be specified.

Example


SPECIALRUNSPEC



5 16 3 8 1 1 /PERMXY100 1500 10*6090 1500 10*6080 1500 10*6570 1500 10*7060 1500 10*7550 1500 10*75 /

256 Keywords FrontSim User GuidePERMY

PERMY Specifies Y-permeability valuesThis keyword specifies the permeability values in the Y-direction.

In FrontSim, off-diagonal (tensor) permeabilities can be specified by the similar keywords: PERMXY, PERMYX,PERMXZ, PERMZX, PERMYZ,PERMZY.






Example


SPECIALx FRONTSIM

RUNSPECx GRID



5 16 3 8 1 1 /PERMY100 1500 10*6090 1500 10*6080 1500 10*6570 1500 10*7060 1500 10*7550 1500 10*75 /

FrontSim User Guide KeywordsPERMZ

257

PERMZ Specifies Z-permeability valuesThis keyword specifies the permeability values in the Z-direction.

In FrontSim, off-diagonal (tensor) permeabilities can be specified by the similar keywords: PERMXY, PERMYX,PERMXZ, PERMZX, PERMYZ,PERMZY.






Example


SPECIALx FRONTSIM

RUNSPECx GRID



5 16 3 8 1 1 /PERMZ72*0 /

258 Keywords FrontSim User GuidePETGRID

PETGRID Recognize grid and properties in Open Petrel FormatThis keyword is used to specify that FrontSim should recognize a grid and properties in Open Petrel Format (.OPF file extension).

All three items are string type values. Each record consists of a file name and up to two items of data, terminated with a slash (/).

1 File name: the name of the .OPF file (the .OPF filename extension is required)

2 Name of SATNUM property: <satnumpropname>

This item is optional.

• DEFAULT: none

3 Name of PVTNUM property: <pvtnumpropname>

This item is optional.

• DEFAULT: none

Example


x FRONTSIMRUNSPEC


PETGRID-- <petgridfile> <satnumpropname> <pvtnumpropname> /

petgridfile.opf 1* mypvtregionproperty /

FrontSim User Guide KeywordsPINCH

259

PINCH Generates connections across pinched-out layersThe keyword should be followed by up to four items, which define the pinchout threshold thickness and the threshold gap between adjacent layers. The data record should be terminated by a slash (/).

1 Pinchout threshold thickness.


• DEFAULT: 0.001

2 Option controlling generation of pinchouts when a minimum pore volume has been set using MINPV.

GAP: Allow NNCs across cells that are inactive due to MINPV even if the thickness exceeds the threshold.

NOGAP: The threshold thickness is strictly observed whether or not the pinched-out cells are inactive due to MINPV.

• DEFAULT: GAP

3 Maximum empty gap allowed between cells in adjacent grid layers for a non-zero transmissibility to exist between them.


• DEFAULT: Infinity (1.0E20)

4 Option for calculating the pinchout transmissibility.

TOPBOT: The pinchout transmissibility is formed from the half-cell Z-direction transmissibilities of the active cells on either side of the pinched-out layer(s).

• DEFAULT: TOPBOT

Pinched-out layers are represented in the grid as layers of inactive cells of zero thickness. The presence of a layer of inactive cells would normally prevent flow from crossing it, between the active cells immediately above and below.

If the keyword PINCH is entered, FrontSim will automatically generate non-neighbor connections between the active cells on either side of the pinched-out layer(s), allowing fluid to flow across it. Generally, the layer or layers of inactive cells are deemed to be pinched-out if their overall cell thickness is less than the specified threshold value.

When PINCH has been specified and if keyword MINPV has been used to set the minimum pore volume a cell must have to be active, then by default, a column of cells may be pinched-out if the pore volumes are less than the minimum value, even if the overall thickness exceeds the threshold thickness. If MINPV is used to switch off cells with small pore volumes (to enhance the convergence of the solver), these cells will not act as a barrier to vertical flow unless the second item equals NOGAP and the overall thickness exceeds the threshold set in the first item. In practice, MULTZ may be set to modify the calculated NNC transmissibility across a thick column of cells. However, any cells with pore volume less than 0.000001 are automatically considered to have a negligible pore volume available for flow and only allows a pinchout NNC across them if the threshold thickness entered as the first item is not exceeded for the column of inactive cells.


SPECIALRUNSPEC


260 Keywords FrontSim User GuidePINCH

By default, the pinchout connection reflects the Z-transmissibility multiplier (MULTZ) specified in the upper of the two connected cells. Item 5 can be set to modify this behavior such that the MULTZ for all pinched out cells is used.

If the third item is defaulted or omitted, then a non-zero transmissibility exists between two adjacent active cells in the same vertical column, whatever the size of the empty gap between the cells, and when MULTZ is not zero for the upper of the two cells. Otherwise, if this gap exceeds the threshold empty gap, then the transmissibility is always set to zero. For a prospective pinchout connection, no NNC is formed if the sum of the empty gaps between all adjacent layers of inactive cells in the pinchout exceeds this threshold.

Notes1 Pinchout connections are only formed across inactive cells, whatever the value set for the

threshold thickness; there is no connection across active cells.

2 The default method (TOPBOT in Item 4) to calculate the transmissibility of a non-neighbor connection due to a pinchout uses a harmonic average of the half-cell Z-direction transmissibilities for the active cells on either side of the pinched-out layer(s).

3 There is one transmissibility calculation available in FrontSim. See "Transmissibility Calculations" in "FrontSim Technical Description".

4 In corner-point geometry, the total thickness of inactive layers in the pinchout (compare Item 1) is computed as the maximum difference in corner-point depths between the active cells on either side of the pinched-out layer(s), for each of the four coordinate lines surrounding the column.

In corner-point geometry, the thickness of the empty gap between two adjacent cells (see Item 3) is taken as minimum difference in corner-point depths between the appropriate coordinate lines.

Example

PINCH--Threshold Gap or--thickness No Gap

0.1 ‘GAP’ /

FrontSim User Guide KeywordsPINCHNUM

261

PINCHNUM Identifies pinchout regionsThe PINCHNUM keyword identifies regions for calculation of pinchouts. The threshold thickness and options for calculating the pinchouts should be supplied for each PINCHNUM region using the PINCHREG keyword.

The PINCHNUM keyword should be followed by one integer for each grid cell, specifying the region number to which it belongs. The data must be terminated by a slash (/).

Any cells not explicitly assigned a value of PINCHNUM are taken to be in region 1.

See also keywords PINCHREG and PINCH.

ExampleTo define 4 separate regions in a 4*4*3 field, with NRPINC=4:


SPECIALx FRONTSIM

RUNSPECx GRID


PINCHNUM1 1 2 21 1 2 23 3 4 43 3 4 41 1 2 21 1 2 23 3 4 43 3 4 41 1 2 21 1 2 23 3 4 43 3 4 4/

262 Keywords FrontSim User GuidePINCHREG

PINCHREG Generates connections across pinched-out layers within regionsThis keyword supplies threshold thickness etc. for calculating pinchouts in multiple regions. The regions should be identified using keyword PINCHNUM. If PINCHNUM is not specified, then PINCHREG applies to flux regions defined by FLUXNUM. If neither PINCHNUM nor FLUXNUM is specified then PINCHREG is ignored.

Each record refers to a separate PINCHNUM or FLUXNUM region and consists of up to five items, detailed below, which are the same as in the PINCH keyword. If the record is defaulted for a region, then no pinchouts are generated in that region. When calculating a pinchout between cells in different regions, the PINCHREG data is taken from the region containing the upper of the two cells.

1 Pinchout threshold thickness.


• DEFAULT: 0.001

2 Option controlling generation of pinchouts when a minimum pore volume has been set using MINPV.

GAP: Allow NNCs across cells that are inactive due to MINPV even if the thickness exceeds the threshold.

NOGAP: The threshold thickness is strictly observed whether or not the pinched-out cells are inactive due to MINPV.

• DEFAULT: GAP

3 Maximum empty gap allowed between cells in adjacent grid layers for a non-zero transmissibility to exist between them.


• DEFAULT: Infinity (1.0E20)

4 Option for calculating the pinchout transmissibility.

TOPBOT: The pinchout transmissibility is formed from the half-cell Z-direction transmissibilities of the active cells on either side of the pinched-out layer(s).

ALL: The pinchout transmissibility is a harmonic average of the Z-direction transmissibilities of all the cells between the active cells on either side of the pinched-out layer(s).

• DEFAULT: TOPBOT

5 Option for accounting for MULTZ through a pinched-out column, if Item 4 has been set to TOPBOT. This item is ignored if Item 4 is set to ALL.

TOP: The transmissibility multiplier applied to the pinchout is the MULTZ for the active cell at the top of the pinchout.

ALL: The transmissibility multiplier applied to the pinchout is the minimum of the MULTZ values for the active cell at the top of the pinchout and all the inactive cells in the pinched-out column.

• DEFAULT: TOP

See the PINCH keyword for further information.


SPECIALx FRONTSIM

RUNSPECx GRID


FrontSim User Guide KeywordsPINCHREG

263

ExampleWith NRPINC=4

PINCHREG--Threshold Gap or Empty--thickness No Gap Gap

0.1 1* 10.0 //

0.2 1* 20.0 /1.0 ‘NOGAP’ /

264 Keywords FrontSim User GuidePINCHXY

PINCHXY Generates horizontal pinchout connections The keyword should be followed by up to two real numbers, which define the X-direction and Y-direction pinchout threshold widths. The data record should be terminated by a slash (/).

1 Threshold width in the X or R direction for horizontal pinchouts


• DEFAULT: 0.001

2 Threshold width in the Y or THETA direction for horizontal pinchouts


• DEFAULT: 0.001

Columns which are pinched-out in the X (or Y) direction are represented in the grid as columns of inactive cells of zero width in the X (or Y) direction. The presence of such a column of inactive cells would normally prevent flow from crossing it in the X (or Y) direction, between the active cells on either side of it.

If the keyword PINCHXY is entered, ECLIPSE automatically generates X (or Y) direction horizontal non-neighbor connections between the active cells on either side of the pinched-out column(s), allowing fluid to flow through it in the X (or Y) direction. Columns are deemed to be pinched-out in the X (or Y) direction if their overall cell width in the X (or Y) direction is less than the specified threshold value.

The X (or Y) direction pinch-out connection reflects the X (or Y) direction transmissibility multiplier (MULTX or MULTY) specified in the left most (or backmost) of the two connected cells.

Notes1 Pinchout connections are only formed across inactive cells, whatever the value set for the

threshold thickness. ECLIPSE 300 only 2 Only horizontal pinchouts in the global grid will be generated. Currently, no local grid

PINCHXY connections will be calculated.

Example


SPECIALx FRONTSIM

RUNSPECx GRID


PINCHXY1* 0.1 /

FrontSim User Guide KeywordsPNODE

265

PNODE Pressure boundary conditionSpecifies the pressure in selected cells in a (global or local) grid. The condition remains valid until it is turned off or assigned to another value. Note that a region defined with this keyword becomes, in effect, an internal boundary condition. No flow occurs within the region.

1 LGR name.

• Default: GLOBAL

2 Pressure at the specified region at reservoir conditions.

1* (default value) turns off conditions previously set.

• UNITS: Bar (METRIC), psi (FIELD)

3 I1

4 I2

5 J1

6 J2

7 K1

8 K2

ExampleSets the pressure in the first cell.



x SCHEDULE

PNODEGLOBAL 320 1 1 1 1 1 1 /

266 Keywords FrontSim User GuidePORO

PORO Specifies the grid block porosity valuesThe keyword should be followed by one non-negative real number for every grid block in the current input box, specifying the fractional porosity value for each cell.

Grid blocks whose pore volume is zero are treated by the program as inactive. This is best done by setting PORO to zero in inactive blocks. It is also possible to use the ACTNUM keyword.



Examples

Example 1

Example 2In this example, porosity values for a 10*10 cross section are set, with an inactive third layer:


SPECIALx FRONTSIM

RUNSPECx GRID



5 16 3 8 2 3 /PORO0.16 0.14 0.12 0.1 0.08 0.09 0.1 0.11 0.12 0.13 0.14 0.140.16 0.14 0.12 0.1 0.09 0.09 0.1 0.11 0.12 0.13 0.14 0.140.15 0.14 0.12 0.1 0.10 0.09 0.1 0.11 0.12 0.13 0.14 0.140.15 0.14 0.12 0.1 0.10 0.09 0.1 0.11 0.12 0.13 0.14 0.140.14 0.14 0.12 0.1 0.09 0.09 0.1 0.11 0.12 0.13 0.14 0.140.14 0.14 0.12 0.1 0.08 0.09 0.1 0.11 0.12 0.13 0.14 0.140.18 0.15 0.12 0.1 0.08 0.09 0.1 0.11 0.12 0.13 0.15 0.150.18 0.15 0.12 0.1 0.09 0.09 0.1 0.11 0.12 0.13 0.15 0.150.15 0.15 0.12 0.1 0.10 0.09 0.1 0.11 0.12 0.13 0.15 0.150.15 0.15 0.12 0.1 0.10 0.09 0.1 0.11 0.12 0.13 0.15 0.150.15 0.15 0.12 0.1 0.09 0.09 0.1 0.11 0.12 0.13 0.15 0.150.15 0.15 0.12 0.1 0.08 0.09 0.1 0.11 0.12 0.13 0.15 0.15 /ENDBOX

PORO10*0.21 10*0.24 10*0.0 30*0.23 20*0.18 20*0.03 /

FrontSim User Guide KeywordsPORV

267

PORV Specifies the grid block pore volumesThe keyword should be followed by one non-negative real number for every grid block in the current input box, specifying the grid block pore volumes.

This keyword is entirely optional. Any pore volumes that are not altered remain at the values calculated by the program from the GRID data.

Grid blocks whose pore volume is zero are treated by the program as inactive. Since the computing time and storage space requirements of a run depend primarily on the number of active grid blocks, it is important that inactive blocks should be unambiguously identified. This can be done either by using the PORV keyword (described here) to overwrite pore volumes directly in the EDIT section, or by setting PORO or NTG to zero in the GRID section. The ACTNUM keyword (in the GRID section) can also be used to identify inactive grid blocks.

Grid blocks are ordered with the X axis index cycling fastest, followed by the Y and Z axis indices. Repeat counts may be used for repeated values (for example 115*195.8). Note that spaces must not be inserted on either side of the asterisk.

• UNITS: METRIC: rm3, FIELD: rb


Example


SPECIALx FRONTSIM

RUNSPECGRID



11 14 3 8 6 6 /PORV24*0 /ENDBOX

268 Keywords FrontSim User GuidePPCWMAX

PPCWMAX Limits the calculated PCW values when SWATINIT is usedThis keyword can by used to limit the scaling of the capillary pressure curves when the SWATINIT keyword has been used to input an initial water distribution. Typically, if the input water saturation is above the connate saturation in blocks well above the transition zone, the scaling of the Pc curve leads to unphysically high capillary pressure values.

The keyword should be followed by NTSFUN (see item 2 of keyword TABDIMS in the RUNSPEC section) records, each terminated by a slash (/).


1 The maximum capillary pressure for this saturation region; it must be greater than the maximum capillary pressure in the corresponding saturation function table.

• UNITS: barsa (METRIC), psia (FIELD), atma (LAB).

• DEFAULT: Infinity (no limit)

2 Either YES or NO, indicating whether the connate saturation should be modified to honor the input water saturation when the capillary pressure limit is exceeded.

• DEFAULT: NO

If a maximum capillary pressure is supplied and Item 2 is set to NO, the input water saturation (from SWATINIT) is not honored in grid blocks that exceed the maximum capillary pressure.

See also the SWATINIT and PCW keywords in the PROPS section.

Examplewith NTSFUN = 2


SPECIALx FRONTSIM

RUNSPECGRIDEDIT


PPCWMAX15.0 YES /17.0 YES /

FrontSim User Guide KeywordsPRCORR

269

PRCORR Request modified Peng-Robinson EoSThis keyword requests that a slightly modified form of the Peng-Robinson equation of state is to be used, as described in "Equations of State" in the "FrontSim Technical Description". This changes the usual form of the value as a function of the component acentric factor.

The keyword has no arguments, and has no effect on equations of state other than the Peng-Robinson.


SPECIALx FRONTSIM

RUNSPECGRIDEDIT


Ωa

270 Keywords FrontSim User GuidePRESSURE

PRESSURE Initial pressuresThe keyword should be followed by one real number for every grid block specifying the initial pressure. The data field should be terminated by a slash(/).


Grid blocks are ordered with the X axis index cycling fastest (from 1 to NDIVIX), followed by the Y axis index (from 1 to NDIVIY), and finally the Z axis index (from 1 to NDIVIZ). Repeat counts may be used for repeated values (for example 115*7200). Note that spaces may not be inserted on either side of the asterisk (*).

This keyword must be used with other keywords (such as SWAT, SGAS, etc.) sufficient to define the initial state explicitly for the run.



SPECIALx FRONTSIM



PRESSURE240*4927 /

FrontSim User Guide KeywordsPRODLIM

271

PRODLIM Water and gas handling limitThis keyword is part of the IOR scale-up option. It describes the field water and gas supply daily limit.

PRODLIM has two arguments, terminated by a slash (/).

1 WATLMT: Maximum field water production rate that facilities can handle.

• UNITS: sm3/day (METRIC), stab/day (FIELD)

• DEFAULT: 0.0

2 GASLMT: Maximum field gas production rate (lean gas + solvent) that facilities can handle.


• DEFAULT: 0.0

Example

Note This works in both history and prediction modes. The RANKING keyword with SLMODE = 1 or 2 is required in order to activate this logic. This still applies even though the solvent allocation logic is not used. You can also disable the allocation logic by disabling all eligible RANKWELL injectors.



x SCHEDULE

PRODLIM-- WATLMT GASLMT

0.2e6 140e6/

272 Keywords FrontSim User GuidePSIDE

PSIDE Pressure boundary conditionSets a pressure boundary condition over an area. The boundary condition is valid (in time) until it is turned off or assigned to another value.

The keyword operates on a subset of the cells on one of the six faces.

1 LGR name.

• Default: GLOBAL

2 Grid face. LEFT, RIGHT, FRONT, BACK, TOP, BOTTOM.

3 Pressure at the specified area at reservoir conditions.




5 Last index axis 1


7 Last index axis 2

If applied on a local grid, the local grid has to be at the boundary of the global grid: the conditions must be applied to the boundary of the simulation region.

Figure 6.5 Grid boundaries

ExampleSet the pressure in the area given by index 1 to 4 on the J axis and by index 1 to 3 on the K axis.



x SCHEDULE

PSIDEGLOBAL LEFT 280 1 4 1 3 /

FrontSim User Guide KeywordsPSIDEH

273

PSIDEH Hydrostatic pressure boundary conditionPSIDEH is used to set a constant pressure boundary condition, as is PSIDE, but the pressure in the cells are adjusted so the cells are in hydrostatic equilibrium. The pressure at the top (not the center) of the uppermost cell is set to the pressure specified.

Sets a pressure boundary condition over an area. The boundary condition is valid (in time) until it is turned off or assigned to another value.

The keyword operates on a subset of the cells on one of the six faces.

1 LGR name.

• Default: GLOBAL

2 Grid face. LEFT, RIGHT, FRONT, BACK, TOP, BOTTOM.

3 Pressure at the specified area at reservoir conditions.




5 Last index axis 1


7 Last index axis 2

If applied on a local grid, the local grid has to be at the boundary of the global grid: the conditions must be applied to the boundary of the simulation region.

Figure 6.6 Grid boundaries

ExampleSet the hydrostatic pressure in the area given by index 1 to 4 on the J axis and by index 1 to 3 on the K axis.



x SCHEDULE

PSIDEGLOBAL LEFT 280 1 4 1 3 /

274 Keywords FrontSim User GuidePVDG

PVDG PVT properties of dry gas (no vaporized oil)The data comprises one or more tables of dry gas PVT functions, each terminated by a slash (/). It must be consistent with the number of PVT regions given by PVTNUM.


Column 1: The gas phase pressure.

Values should increase monotonically down the column.


Column 2: The corresponding gas formation volume factor.

Values should decrease down the column.

• UNITS: rm3/sm3 (METRIC), rb/Mscf (FIELD).

Column 3: The corresponding gas viscosity.

Values should be level or increasing down the column.

• UNITS: cP (METRIC), cP (FIELD).

There must be the same number of entries in each column of a given table. In FrontSim, a single line specifies incompressible gas.

Note It is recommended that the maximum pressure in PVT tables should be set slightly greater than the maximum hydrocarbon pressure expected in the run (the highest of either the maximum injection BHP or the pressure at the water contact), and that the minimum pressure should be set to atmospheric. You should ensure that PVT data complies with the total compressibility checks described in the "ECLIPSE Technical Description". FrontSim issues warning messages if the data does not comply, and unphysical results and/or program errors will result.

ExampleWith one pressure table:


SPECIALx FRONTSIM

RUNSPECGRIDEDIT

x PROPSREGIONSSOLUTIONSUMMARY

PVDG400.000 5.90000 .01300800.000 2.95000 .013501200.00 1.96000 .014001600.00 1.47000 .014502000.00 1.18000 .015002400.00 .98000 .015502800.00 .84000 .016003200.00 .74000 .016503600.00 .65000 .017004000.00 .59000 .017504400.00 .54000 .018004800.00 .49000 .018505200.00 .45000 .019005600.00 .42000 .01950 /

FrontSim User Guide KeywordsPVDO

275

PVDO PVT properties of dead oil The data comprises one or more tables of dead oil PVT functions, each terminated by a slash (/). It must be consistent with the number of PVT regions given by PVTNUM.


Column 1 The oil phase pressure

Values should increase monotonically down the column.


Column 2 The corresponding oil formation volume factor

Values should decrease down the column.

• UNITS: rm3/sm3 (METRIC), rb/stb (FIELD).

Column 3 The corresponding oil viscosity




In FrontSim, a single line specifies incompressible oil.

ExampleWith NTPVT=2:




PVDO400 1.012 1.161200 1.0040 1.1642000 0.9960 1.1672800 0.9880 1.1723600 0.9802 1.1774400 0.9724 1.1815200 0.9646 1.1855600 0.9607 1.19 /800 1.0255 1.141600 1.0172 1.142400 1.0091 1.143200 1.0011 1.144000 0.9931 1.144800 0.9852 1.145600 0.9774 1.14 /

276 Keywords FrontSim User GuidePVTG

PVTG PVT properties of wet gas (with vaporized oil)The data comprises one or more tables of wet gas PVT functions, each terminated by a slash (/). It must be consistent with the number of PVT regions given by PVTNUM. A single table consist of at least 2 records each terminated with a slash (/). Each record gives PVT data for a particular gas phase pressure (Pg). A table is terminated by a null record (that is a record with no data before the terminating slash). This table may be generated by PVTi.

Most records contain 4 numbers and a terminating slash:

Item 1: The gas phase pressure (Pg).

Within a table, records should be arranged in order of increasing Pg.


Item 2: The vaporized oil-gas ratio for saturated gas at pressure Pg.


Item 3: The gas formation volume factor for saturated gas at Pg.

• UNITS: rm3/sm3 (METRIC), rb/Mscf (FIELD)

Item 4: The gas viscosity for saturated gas at Pg.

• UNITS: cP (METRIC), cP (FIELD)

However some records (optionally all) contain additional data that defines the properties of under-saturated gas at the specified value of Pg. This extra data must be specified for the highest Pg in each table. The additional data takes the form of 3 columns that continue from items 2, 3 and 4 above.

Each column may have up to NRPVT (item 6 in keyword TABDIMS) entries.

Column 2: The vaporized oil-gas ratio (Rv).

Values of Rv must decrease down the column (starting from the value for saturated gas).


Column 3: The gas formation volume factor (Bg) corresponding to Rv and Pg.

• UNITS: rm3/sm3 (METRIC), rb/Mscf (FIELD)

Column 4: The gas viscosity ( ) corresponding to Rv and Pg.


There must be the same number of entries in each column. If no additional data is supplied for a particular value of Pg, it locates the next higher value of Pg for which undersaturated PVT data is available, and takes a scaled copy of the FVF and viscosity curves supplied there.

Note Data for undersaturated gas must be provided for the highest Pg in the table.


SPECIALx FRONTSIM

RUNSPECGRIDEDIT


μg

FrontSim User Guide KeywordsPVTG

277


ExampleWith NTPVT=2. NRPVT must have been set ≥ 2 and NPPVT ≥ 7:

PVTG30 0.00014 0.0523 0.0234

0 0.0521 0.0238 /90 0.00012 0.0132 0.0252

0 0.0131 0.0253 /150 0.00015 0.00877 0.0281

0 0.00861 0.0275 /210 0.00019 0.00554 0.0318

0 0.00555 0.0302 /270 0.00029 0.00417 0.0355

0 0.00421 0.0330 /330 0.00049 0.00357 0.0392

0 0.00361 0.0358 /530 0.00060 0.00356 0.0393

0 0.00360 0.0359 // null record to terminate table 160 0.00014 0.0523 0.0234 /120 0.00012 0.0132 0.0252 /180 0.00015 0.00877 0.0281 /240 0.00019 0.00554 0.0318 /300 0.00029 0.00417 0.0355 /360 0.00049 0.00357 0.0392 /560 0.00060 0.00356 0.0393

0 0.00360 0.0359 / undersaturated data for Pg=560/ null record to terminate table 2

278 Keywords FrontSim User GuidePVTNUM

PVTNUM PVT region numbersThe keyword should be followed by one integer for every grid block in the current input box specifying the PVT region to which it belongs. The region number should not be less than 1. The data must be terminated by a slash (/).

The PVT region number specifies which set of PVT tables (input using DENSITY, PVDG, PVDO, PVTG, PVTO, PVTW and ROCK in the PROPS section) should be used to calculate PVT properties of fluids in each grid block for a black oil model.

For a compositional model, PVTNUM is only used to reference the water properties defined using DENSITY, or PVTW and the rock compressibility specified by ROCK if required.


ExampleWith NTPVT=4, NDIVIX=8, NDIVIY=6, NDIVIZ=5 and no input BOX set:


SPECIALx FRONTSIM



PVTNUM8*1 16*2 8*3 16*48*1 16*2 8*3 16*48*1 16*2 8*3 16*48*1 16*2 8*3 16*48*1 16*2 8*3 16*4 /

FrontSim User Guide KeywordsPVTO

279

PVTO PVT properties of live oil (with dissolved gas)The data comprises one or more tables of live oil PVT functions, each terminated by a slash (/). It must be consistent with the number of PVT regions given by PVTNUM. A single table consists of at least 2 records each terminated with a slash (/). Each record gives PVT data for a particular dissolved gas-oil ratio (Rs). A table is terminated by a null record (that is a record with no data before the terminating slash).

Most records contain 4 numbers and a terminating slash:

Item 1: The dissolved gas-oil ratio (Rs).

Within a table, records should be arranged in order of increasing Rs.


Item 2: The bubble point pressure (Pbub) for oil with dissolved gas-oil ratio given by item 1.


Item 3: The oil formation volume factor for saturated oil at Pbub.

• UNITS: rm3/sm3 (METRIC), rb/stb (FIELD)

Item 4: The oil viscosity for saturated oil at Pbub.


However some records (optionally all) contain additional data which defines the properties of under-saturated oil at the specified value of Rs. This extra data must be specified for the highest Rs in each table. The additional data takes the form of 3 columns, which continue from items 2, 3 and 4 above. Each column may have up to NPPVT (see item 4 in keyword TABDIMS) entries.

Column 2: The oil phase pressure (Po).

Values of Po must increase down the column (starting from Pbub).


Column 3: The oil formation volume factor (Bo) corresponding to Rs and Po.

Values of Bo must decrease down the column.

• UNITS: rm3/sm3 (METRIC), rb/stb (FIELD)

Column 4 : The oil viscosity ( ) corresponding to Rs and Po.

Values of do not normally decrease down the column.


There must be the same number of entries in each column. If no additional data is supplied for a particular value of Rs, it locates the next higher value of Rs for which undersaturated PVT data is available, and takes a scaled copy of the FVF and viscosity curves supplied there. The scaling is done in such a way that the compressibility and ‘viscosibility’,

[EQ 6.35]

are preserved.


SPECIALx FRONTSIM

RUNSPECGRIDEDIT


μo

μo

μodPod

---------⎝ ⎠⎛ ⎞ μo⁄

280 Keywords FrontSim User GuidePVTO

Note that data for undersaturated oil must be provided for the highest Rs in the table.


ExampleWith NTPVT=2. NRPVT must have been set ≥ 11 and NPPVT ≥ 6:

PVTO0.165 400 1.012 1.17 /0.335 800 1.0255 1.14 /0.500 1200 1.038 1.11 /0.665 1600 1.051 1.08 /0.828 2000 1.063 1.06 /0.985 2400 1.075 1.03 /1.130 2800 1.087 1.00 /1.270 3200 1.0985 0.98 /1.390 3600 1.11 0.95 /1.500 4000 1.12 0.94 /1.600 4400 1.13 0.92

4800 1.1255 0.925200 1.1210 0.925600 1.1165 0.92 / data for undersaturated oil with Rs=1.6

/ null record terminates table 10.275 400 1.1334 1.17 /0.610 1200 1.1626 1.11 /0.938 2000 1.1906 1.06 /1.240 2800 1.2174 1.00 /1.500 3600 1.2432 0.95

4000 1.2382 0.954400 1.2332 0.954800 1.2283 0.955200 1.2235 0.955600 1.2186 0.95 / data for undersaturated oil with Rs=1.5

1.610 4000 1.2544 0.94 /1.720 4400 1.2656 0.92

4800 1.2606 0.925200 1.2555 0.925600 1.2505 0.92 / data for undersaturated oil with Rs=1.72

/ null record terminates table 2

FrontSim User Guide KeywordsPVTW

281

PVTW Water PVT functionsThe data comprises one or more records, each terminated by a slash (/). It must be consistent with the number of PVT regions given by PVTNUM.


Item 1: The reference pressure (Pref) for items 2 and 4.


Item 2: The water formation volume factor at the reference pressure, Bw(Pref)

• UNITS: rm3/sm3 (METRIC), rb/stb (FIELD).

Item 3: The water compressibility

• UNITS: 1/bars (METRIC), 1/psi (FIELD).

Item 4: The water viscosity at the reference pressure .


Item 5: The water “viscosibility” (Not used by FrontSim)

ExampleWith NTPVT = 2:


SPECIALx FRONTSIM

RUNSPECGRIDEDIT


PVTW3600.0000 1.00341 3.00E-06 0.52341 /3900 1 2.67E-06 0.56341 /

CBwdPd

----------⎝ ⎠⎛ ⎞ Bw⁄–=

μw Pref( )

282 Keywords FrontSim User GuideRANKING

RRANKING Ranking of solvent allocation

This keyword is part of the IOR tracer logic option. It triggers different options for ranking the solvent allocation.


1 SLMODE: Flag for determining solvent logic mode

0 = No solvent logic is used

1 = Type I solvent allocation logic

2 = Type II solvent allocation logic

• DEFAULT: 1

2 ALMODE: Selects the ranking and mobilization curve scaling mode

The parameter can take the values listed. Note that:

• 0, 1, 4, 5 support scaling by perforation, when each perforation is scaled separately using the truth model with its own thickness

• 2, 3 support scaling by layer, when every layer with multiple perforation has the same scaling based on the thickness from all perforation within the same layer. Scaling by layer also supports horizontal wells. Layers are defined by the perforations range by using multiple RANKWELL keywords for the same well.

• 1, 3, 5 support the use of stop solvent at slug size mode during solvent allocation.

0 = VREF scaling with thickness ratio of perforation cell thickness and THK in the supplied TREFFIC curve, or VREF (HCPV) scaling with thickness ratio of cell thickness and THK defined in RANKWELL. Supports THK=0, with internal thickness ratio of 1.0.

1 = Activate StopSolventAtSlugSize option, in addition to the scaling used in ALMODE=0. Only used when SLMODE=2.

2 = Same as ALMODE=0, with the cell thickness replaced by the layer thickness defined in RANKWELL perforation. Supports horizontal well scaling.

3 = Activate StopSolventAtSlugSize option, in addition to the scaling used in ALMODE=2. Only used when SLMODE=2.

4 = RANKWELL parameter scaling with layer VREF (typically TPV volume) thickness ratio internal to code, with thickness ratio of cell thickness and total active well perforation thickness. Does not support horizontal wells.

5 = Activate StopSolventAtSlugSize option, in addition to scaling used in ALMODE=4. Only used when SLMODE=2.

• DEFAULT: 0

Note ALMODE=0 is the only supported scaling in 2001A. ALMODE=2 and 3 is the defaulted behavior of 2002A and 2002A_1, which is also the only scaling supported.

3 MINSSZ: Slug size minimum fraction. Applies to all wells. The parameter is only valid if ALMODE=1.

• UNITS: Fraction of HPV

• DEFAULT: 0.0



x SCHEDULE

FrontSim User Guide KeywordsRANKING

283

4 NWELLFRC: Solvent fraction allocated to new wells. The parameter is only valid if ALMODE=2. NWELLFRC is effective only with SLMODE=2.

• DEFAULT: 1.0

Examples

Example 1: Ranking by well list

Example 2: Ranking by slug size

NoteRelease 2003A and beyond supports all modes defined above.

RANKING-- SLMODE ALMODE

1 0 /

RANKING -- SLMODE ALMODE MINSSZ NWELLFRC

2 1 0.02 0.10 /

284 Keywords FrontSim User GuideRANKWELL

RANKWELL Ranked well listThis keyword defines the assignment of mobilization curves to solvent injection wells in both IOR history and prediction models.

Multiple RANKWELL listings for different perforations of the same well are supported in history mode. This is useful when a well completion spans over multiple layers. Mobilization curves must have separate names if multiple RANKWELLS are used for the same well. This means all three curve names need to be different for any two neighboring RANKWELL listings of the same well.

Multiple RANKWELL listings are not valid in predictive mode of solvent allocation, where only the last listing of the RANKWELL keyword is used. This limitation is due to the fact that solvent allocation in predictive mode is well-based.

The RANKWELL keyword is followed by any number of records, each containing the following items of data, and each terminated with a slash (/).


1 WNAME: The well name, restricted to a maximum of 8 characters in length.

2 I1: The position of the well/completion in the reservoir, enabling ranking per completion. Values are always positive.

• DEFAULT: If defaulted then all completions of the well are assumed.

3 I2: The position of the well/completion in the reservoir, enabling ranking per completion. Values are always positive.


4 J1: The position of the well/completion in the reservoir, enabling ranking per completion. Values are always positive.


5 J2: The position of the well/completion in the reservoir, enabling ranking per completion. Values are always positive.


6 K1: The position of the well/completion in the reservoir, enabling ranking per completion. Values are always positive.


7 K2: The position of the well/completion in the reservoir, enabling ranking per completion. Values are always positive.


Note The numbers must always be defaulted in pairs. This means, for example, that if I1 is defaulted, then I2 must also be defaulted. Only one completion can fluctuate at one time. This means that if I2>I1 then J1=J2 and K1=K2.

8 RANK: Flag to determine whether this well participates in the solvent logic. The following two modes are supported:

0 = Well does not participate in the solvent logic. It supports tracer injection in the history mode.



x SCHEDULE

FrontSim User Guide KeywordsRANKWELL

285

1 = Well does participate in the solvent logic. It supports tracer injection in the predictive mode.

A well must be updated when it is switched from history mode to predictive mode.

• DEFAULT: 1

9 HPV: HPV is the hydrocarbon pore volume associated with this injector pattern. This value is used solely to convert the specified slug size fractions (TARGSSZ, MINSSZ, and MAXSSZ) into RVB/day of solvent injection per well.

• UNITS: rm3 (METRIC), RB (FIELD)

• DEFAULT: None.

10 TARGSSZ: Target solvent slug size fraction for this well.


• DEFAULT: to the global TARGSSZ parameter defined in the SOLVSLUG keyword for the same year.

11 MINSSZ: Minimum solvent slug size fraction for this well. MINSSZ can be the same as Target Slug Size for previous models defined for injector.

You can select one of two methods:

a Always re-rank wells by setting this parameter to the actual minimum slug size, as described in the SOLVSLUG keyword

b Re-rank wells only after the target slug size is reached, as defined in TARGSSZ.


• DEFAULT: to the global MINSSZ parameter defined in the SOLVSLUG keyword for the same year.

12 MAXSSZ: Maximum solvent slug size fraction for this well.


• DEFAULT: to the global MAXSSZ parameter defined in the SOLVSLUG keyword for the same year.

13 MOBCIWB: Name of mobilization curve as specified in the TREFFIC keyword. Required for the IWAG lean gas injection before the MWAG solvent injection.

• DEFAULT: None

14 MOBCMW: Name of mobilization curve as specified in the TREFFIC keyword. Required for the MWAG solvent injection.

• DEFAULT: None

15 MOBCIWA: Name of mobilization curve as specified in the TREFFIC keyword.

Required for the IWAG lean gas injection after the MWAG solvent injection.

• DEFAULT: None

16 TPV: This option allows you to re-scale the mobilization curve by overriding the TPV value entered on the TREFFIC keyword.


• DEFAULT: to the global TPV parameter in the TREFFIC keyword with the matching MOBCRV name.

17 THK: This option is used only when SLMODE =1 in RANKING keyword.

286 Keywords FrontSim User GuideRANKWELL

It allows you:

a to specify either dimensional or dimensionless scaling for IOR solvent injection

b to select dimensionless re-scaling of the mobilization curve. The dimensionless scaling is based on:

You can select dimensional re-scaling by defaulting THK and by specifying a non-zero THK value entered on the name of the TREFFIC curve used. Note that the IOR logic internally scales the mobilization curve based on the ratio

where THK is entered in the TREFFIC keyword.


• DEFAULT: The defaulting of this option switches to dimensional re-scaling when SLMODE=1, as described above. The option is not in use when SLMODE=2.

Note For discussion of scaling options, refer to RANKING/ALMODE, where all scaling options are discussed.

18 VREF: This option allows you to re-scale the mobilization curve (MOBCRVB, MOBCRVW, or MOBCRVA) by overriding the TPV value entered on the TREFFIC keyword. See TREFFIC for more details.


Examples

Example 1

THK(Field or RANKWELL)THK TREFFIC( )

----------------------------------------------------------------------

reservoir-thickness-at-the-injectorTHK

---------------------------------------------------------------------------------

RANKWELL--WNAME I1 I2 J1 J2 K1 K2 RANK HPV TARGSSZ MINSSZ MAXSSZ MOBCIWB MOBCMW MOBCIWA TPVTHK VREF'C1A-02' 6* 1 10.72e6 0.3 0.0 0.5 crv4 crv2 crv4 10.e06 50 10.72e6 /'C1A-04' 6* 1 3.85e6 0.3 0.0 0.5 crv4 crv1 crv4 0.0e06 60 10.72e6 /'C1A-05' 6* 0 16.97e6 0.3 0.1 * crv4 crv2 crv4 3* /'C1A-06' 6* 1 9.20e6 0.3 0.2 0.9 crv4 crv2 crv4 /

/

FrontSim User Guide KeywordsRANKWELL

287

Example 2

Notes1 This RANKWELL list contains only the wells that are solvent gas or lean gas injectors to be

used as tracer with the IOR tracer module.

2 For dimensional scaling, VREF is defaulted to that of truth model defined in the TREFFIC listing. For dimensionless scaling, VREF is typically listed in the RANKWELL keyword in order to replace the value in the applicable TREFFIC keyword.

3 TPV is used in the TREFFIC keyword for flooding dependence scaling. It is only meaningful to specify a value when the option is used with validated D,E,F values in the applicable TREFFIC keyword.

RANKWELL--WNAME I1 I2 J1 J2 K1 K2 RANK HCPV TARGSSZ MINSSZ MAXSSZ MOBCIWB MOBCMW MOBCIWATPV VREF THK‘INJ_1’ 6* 1 10.7e6 0.3 0.0 0.5 MobCrv1 MobCrv1 MobCr

v2 40e06 10.7e06 121. 2/

288 Keywords FrontSim User GuideREFINE

REFINE Initiates data input for a named local gridThis keyword is used to indicate that subsequent data refers to a named local grid. The keyword is followed by the local grid name, terminated with a slash. Subsequent keywords, from the available sets described below, are taken to refer to the specified local grid, until either an ENDFIN or another REFINE keyword is entered.

The REFINE keyword is available in the GRID, EDIT and SOLUTION sections.

There are restrictions on the keywords that can be used with this keyword, as described in the following paragraphs.

GRID sectionThe REFINE keyword can be used in the GRID section to return to a local grid that has previously been introduced with CARFIN to make further modifications to its grid data or to supply additional data.

In addition, the BOX, COPY, EQUALS and MULTIPLY keywords can be used to set or modify GRID section keywords in regions of the local grid.

EDIT sectionThe following grid arrays may be edited for a local grid:

• TRANX

• TRANY

• TRANZ

In addition, the BOX, COPY and EQUALS keywords can be used to set or modify the above keywords in regions of the local grid. If any grid block values are defaulted, the host global grid cell value is used.

SOLUTION sectionIn the SOLUTION section, the REFINE keyword can be used when the run is initialized by enumeration, to specify the initial conditions in the local grid cells. If the initial conditions for the local grid cells are not set in this way, they default to the initial conditions in their global grid host cells.

The REFINE keyword can be followed by any of the enumeration keywords that specify initial conditions on a cell by cell basis:

• PRESSURE

• SWAT

• SGAS

The BOX, COPY, ADD and EQUALS keywords are not available in the SOLUTION section.

The block of data initiated by the REFINE keyword is terminated by either an ENDFIN keyword or another REFINE keyword.



SUMMARYx SCHEDULE

FrontSim User Guide KeywordsREFINE

289

Examples

Example 1 EDIT section

Example 2SOLUTION section

REFINE'LGR1' /EQUALS'PORV' 100.0 1 2 1 2 3 4 /'TRANX' 1000.0 1 4 1 4 4 4 /

/ENDFIN

REFINE'LGR1' /PRESSURE16*390016*390516*391016*3915 /SWAT32*0.2216*0.2516*0.28 /ENDFIN

290 Keywords FrontSim User GuideRESTART

RESTART Read solution from a restart fileA line containing between 2 and 4 items of data should follow the keyword, terminated by a slash (/).

1 The root name of the RESTART file.

2 The number of the report from which the run is to be restarted.

See also keyword RPTRST.

ExampleThis causes the current run to restart from report time 11 of a previous run whose root file-name was BASE, reading the solution data from the RESTART file.

Restarting a FrontSim runWith FrontSim it is only possible to restart as a flexible run. This means that the data file must be processed again. It is possible to change some of the input as long as the grid and geometry properties remain unaltered. The start should not be altered.

By default, FrontSim stores all time-dependent data (for example grid block solution variables, status of wells, tracer variables, fluid volumes, etc.) in the restart file. The user just has to be sure that a restart files (multiple or unified) are generated.

Note Currently it is not possible to increase (or decrease) the number of tracers (using the WTRACER keyword, for example).

A complete data file and an initial solution are required to generate a restart run. The well definitions (WELSPECS and COMPDAT) are also read from the restart file.

Some (SCHEDULE) keywords are not written to the RESTART file and should be specified in the start of the SCHEDULE section of the restart input file if they were included in the original data:

• Reservoir property keywords - boundaries, aquifers, etc.: AQUFLUX, FLUXSIDE, PNODE, PSIDE and PSIDEH

• Simulation controls - output, tuning, etc.: FSSOLVE, FSWEAKW, GOCADOUT, GUIDERAT, MAXSTEP, NEXTSTEP, MINSTEP, TSCRITFS, OPTIONFS, RANKING, RPTLINFS, RPTPRINT, RPTRST, RPTSCHED, TUNEFS1D, TUNEFSPR and TUNEFSSA, WRFTPLT.

• Other keywords that need to specified: VFPPROD, VFPINJ, WELLSTRE, WINJGAS, WPIMULT, WTMULT, WSOLVENT, WCONINJP.

To do a restart from, say, the 11th report time of run BASE, the procedure is (alternatively SKIPREST could be used to skip all keyword before restart time)

1 Think of a new file name root - say RESTART1.

2 Copy the data file BASE.DATA into RESTART1.DATA.


SPECIALx FRONTSIM



RESTARTBASE 11 /

FrontSim User Guide KeywordsRESTART

291

3 Edit RESTART1.DATA.

• In the SOLUTION section, delete all equilibration or enumeration keywords, and any analytic aquifer keywords.

• Insert the RESTART keyword to specify the restart file and report number;

• In the SCHEDULE section, delete the well and time-stepping keywords up to and including the restart time at report number 11 in the example. Modify the schedule data after report 11 as required.

4 Submit the run with RESTART1 as the root filename.

Restarting from a ECLIPSE restart fileTo run a FrontSim restart based on an ECLIPSE restart the fluids in place and the cumulative flows should be included in the restart file by including the RPTSCHED keyword in the ECLIPSE run, for example:

Old format

or

New format

or

NotesThe restarted run must be unified (UNIFOUT is present) if the base run is unified (UNIFOUT is present) (or the other way around with multiple runs).

In some cases some there might be some minor differences in results when comparing the restart run with the original (base) model.

RESTARTBASE 11 /

RPTSCHED6* 4/

RPTRST2 1* 1 /

RPTSCHED'RESTART=4 ' /

RPTRST'BASIC=2' 'FIP=1 ' /

292 Keywords FrontSim User GuideROCK

ROCK Rock compressibilityThe data comprises a number of records (given by PVTNUM or 1), each terminated by a slash (/).


Item 1: The reference pressure (Pref).


Item 2: The rock compressibility

[EQ 6.36]

where V is the pore volume.

• UNITS: 1/bars (METRIC), 1/psi (FIELD).

The NTPVT records correspond to the PVT region numbers, which are set using keyword PVTNUM.

Note If ROCK is omitted, the rock matrix is assumed to be incompressible.



SPECIALx FRONTSIM

RUNSPECGRIDEDIT


ROCK3600.00 .40E-05 /3600.00 .40E-05 /3000 0 /

C VdPd

------⎝ ⎠⎛ ⎞ V⁄=

FrontSim User Guide KeywordsROCKNUM

293

ROCKNUM Rock compaction table region numbersThe keyword should be followed by one integer for every grid block in the current input box, specifying the Rock Compaction table region to which it belongs. The region number should not be less than 1 or greater than the number of ROCK tables defined.

If ROCKNUM is not specified the values in PVTNUM are used instead.

ExampleWith, NDIVIX=8, NDIVIY=6, NDIVIZ=5 and no input BOX set:


SPECIALx FRONTSIM


x REGIONSSOLUTIONSUMMARY

ROCKNUM8*1 16*2 8*3 16*48*1 16*2 8*3 16*48*1 16*2 8*3 16*48*1 16*2 8*3 16*48*1 16*2 8*3 16*4 /

294 Keywords FrontSim User GuideRPTALLOC

RPTALLOC Controls on output to the .ALN fileThis keyword controls the formatted output of allocation/bundle information to the .ALN -file for better connectivity to OFM or MS EXCEL. By defaults units for parameters are not specified. This allows easier import of data into OFM. Units should be set in OFM. The keyword should be followed by a list of mnemonics which control the output of data to the .ALN file. The list should be terminated by a slash (/). Note that no ALN files will be written if no RPTALLOC keywords are specified.

Unified ALN files can be produced by specifying UNIFOUT in the RUNSPEC section.

For additional control over the output, integer values greater than one may be assigned to selected mnemonics using the syntax: mnemonic=integer where there must be no spaces either side of the equals sign.

These entries are supported by FrontSim:



x SCHEDULE

Table 6.31 Controls on output to .ALN file

Input Keyword Or Mnemonic Output

BASIC Output of basic ALN files

If set to 1 ALN files are created at every report time, but if the files are not unified, only the last one in the run is kept.

If set to 2 ALN files are created at every report time until this switch is reset, and all are kept.

If set to 3 ALN are created every nth report time. The frequency is governed by the mnemonic FREQ.

BOUND Allocation data for I- and P-Boundaries are included

TYPE Indicate at which level information is reported:

If set to 1 - well level output (default)

If set to 2 - pattern level output

If set to 3 - zone level output

UNITS Unit information:

If set to 1 - report at surface conditions (default)

If set to 2 - report at reservoir conditions

FORMAT Header information:

If set to 1 - report with header row containing units information (default)

If set to 2 - report with no header row containing units information

FREQ Controls the frequency of the ALN files if BASIC is set equal to 3.

WPBASIS If set to 1 (default) - output are produced on injector basis

If set to 2 - output are produced on producer basis

If set to 3 - output are produced on both injector and producer basis

NOOFM If set to 1 - reports are created in a non-compatible format (with units and so on.)

FrontSim User Guide KeywordsRPTALLOC

295

Example

RPTALLOCBASIC=3 FREQ=2 TYPE=1 /

296 Keywords FrontSim User GuideRPTLINFS

RPTLINFS Sets report frequency for line graph outputSets the report frequency for line graph output to SUMMARY files.

The keyword should be followed by a record containing one of the two parameters described below. The two parameters are mutually exclusive: one of them should be defaulted with 1*.

The purpose of this keyword is to be used with 1 step simulations.

The record should end with a slash (/).

1 Interval: Number of days between points in the line graph file.

• DEFAULT: computed by FrontSim.

2 nstep: Number of times to report to the line graph file during the simulation

• DEFAULT: 100

Notes1 Interval: if the interval between points is set greater than the length of the report step, a

point will be written at the end of the report step. This is equivalent to the behavior of the ECLIPSE RPTONLY keyword.

2 nstep: if the number of report steps defined in the SCHEDULE section exceeds the default value, the number will be increased to report one point for each step.

3 If both items are defaulted or the keyword is not specified, only one point at the end of the report step is generated.

4 If both items 1 and 2 are defaulted, FrontSim will by default write summary reports at all timesteps when any one of the timestep keywords NEXTSTEP, MINSTEP, MAXSTEP or TSCRITFS is specified.

Examples

Example 1Reports to file every 200th day of the simulation.

Example 2Reports to file 50 times during the simulation.



x SCHEDULE

RPTLINFS200 1* /

RPTLINFS1* 50 /

FrontSim User Guide KeywordsRPTPRINT

297

RPTPRINT Control printed simulation reportsFrom the 2002A release onwards, use of this keyword is discouraged. It is superseded by RPTSCHED.

This keyword controls the output of printed reports. It may be specified any number of times in the SCHEDULE section. RPTPRINT will always report FIP properties (field and FIPNUM regions) and well properties (wells and completions) to the print file. If the user wants to control what is reported to the print file the RPTSCHED keyword should be used instead.

FrontSim 1 Report step summary frequency.

• DEFAULT: 0

2-16 15*

17 Allocation info to extra .alloc file (if 1).

• DEFAULT: 0

Note For compatibility with ECLIPSE, the format has changed since the 2000A release of FrontSim.

ExampleRPTPRINT will generate reports every second timestep, and include reporting bundle information to the .alloc file.


SPECIALx FRONTSIM


x SCHEDULE

RPTPRINT2 15* 1 /

298 Keywords FrontSim User GuideRPTRST

RPTRST Controls on output to the RESTART fileThe keyword should be followed by a list of mnemonics which control the output of data to the Restart file. The list should be terminated by a slash (/). Note that no restart files will be written if no RPTRST input keywords or mnemonics are specified.

For additional control over the output, integer values greater than one may be assigned to selected mnemonics using the syntax:

mnemonic=integer

where there must be no spaces either side of the equals sign.

Optionally, for back compatibility, a list of integers, terminated with a slash, may be used to indicate the required output. A value less than or equal to zero switches off the corresponding output. Values greater than zero switch the output on. Repeat counts (for example 3*0) can be used if required (with no spaces before or after the asterisk). The integer list cannot be mixed with mnemonics.

The RESTART mnemonic writes a record from which FrontSim can be restarted, using the RESTART keyword in the SOLUTION section.

See also keyword RPTSLN.

These entries are supported by FrontSim:



x SCHEDULE

Table 6.32 Controls on Output to the RESTART file

Input Keyword Or Mnemonic

Output Integer Value Position

ALLOC Enables output of allocation/bundle information to

the restart file

BASIC Output of basic Restart files

If set to 1 restart files are created at every report time, but if the files are not unified, only the last one in the run is kept (designed for fail-safe restarts).

If set to 2 restart files are created at every report time until this switch is reset, and all are kept (default).

If set to 3 restart files are created every nth report time. The frequency of the restarts is governed by the mnemonic FREQ.

1

FIP Output of fluids-in-place (only for phases defined in RUNSPEC)

FLOWS Enables output of the FLORES arrays described in keyword RPTSLN.

FLOWTOT Enables output of the FLUX arrays

FLUXDENS Flow rate pr areal. STRDENS (number of streamlines in cell) and VTCELL (Abs (Vt)) will be made available as 3d vectors.

FREQ Controls the frequency of the restart files if BASIC is set equal to 3.

6

PBPD Output of bubble point and dew point pressures

FrontSim User Guide KeywordsRPTRST

299

POT Output of phase potentials

(including the initial contact corrected potential) (only for phases defined in RUNSPEC)

PRESALT Outputs three additional pressure arrays to the restart arrays for 3-phase data sets (using FULLIMP, IMES or AIM). only. Arrays written are:

PRES_GLB pressure from the FrontSim global pressure solver

PRES_MAP pressure from the saturation solver via the mapping algorithm, if this has not been disabled by item 7 of OPTIONFS.

PRES_HCV the hydrocarbon pore volume weighted average of the pressure determined by the saturation solve

PRESSURE Output of grid block pressures

RESTART Output of data required for flexible restart

RPORV Output of reservoir pore volumes at Reservoir conditions

RS Output dissolved GOR (Rs) (In compositional runs this is interpreted as the GOR at surface conditions of the liquid phase in the reservoir). Only included if RS is defined and not constant.

RV Output vaporized OGR (Rv) (In compositional runs this is interpreted as the OGR at surface conditions of what was the vapor phase in the reservoir.). Only included if RV is defined and not constant.

SGAS Output of grid block gas saturations (only if GAS is set in RUNSPEC)

STREAM Number of streamlines to be output (RPTSLN) 28

SWAT Output of grid block water saturations (only if WAT is set in RUNSPEC)

TCONC Tracer concentration (if tracers are included)

TOF TOF[=n] Requests output for Time Of Flight (TOF) arrays.

If n is supplied, it specifies upper limit on TOF value written to arrays.

If the TOF mnemonic is not supplied, there will be no TOF output.

DEFAULT: n=10000

Arrays written are calculated using the streamline with maximum flow rate through the cell:

TIME_BEG - Time from beginning

TIME_END - Time to end

ID_BEG - Identifier at beginning

ID_END - Identifier at end

32

TOFSENS Sensitivities of TOF with respect to permeabilities

Table 6.32 Controls on Output to the RESTART file (Continued)



300 Keywords FrontSim User GuideRPTRST

ExampleRestart files every second step (.X0002,...).

XMF Output of liquid component mole fractions in a compositional run (fraction of each component in liquid)

YMF Output of vapor component mole fractions in a compositional run (fraction of each component in gas)

ZMF Output of total component mole fractions in a compositional run

RPTRSTBASIC=3 FREQ=2 TOF /

Table 6.32 Controls on Output to the RESTART file (Continued)



FrontSim User Guide KeywordsRPTSCHED

301

RPTSCHED Controls on output from SCHEDULE sectionThe keyword should be followed by a list of mnemonics that control the output of SCHEDULE section data to the Print file. Wherever possible, the mnemonics correspond to the related keywords. The list must be terminated with a slash (/).

The RPTSCHED keyword may be used to reset output controls for the SCHEDULE section as often as required.

For additional control over the output, integer values greater than one may be assigned to selected mnemonics using the syntax: Mnemonic=integer

where there must be no spaces on either side of the equals (=) sign.

The following table lists the mnemonics available.

Note The ALLOC=3 option must be used when generating output that can be loaded into the OilField Manager (OFM) application.


SPECIALx FRONTSIM


x SCHEDULE

Table 6.33 Mnemonics available for RPTSCHED keyword

Mnemonic OutputFREQ Report frequency

FIP Output of fluid in place and inter-region flow reports:

1 gives fluids in place are reported for the whole field.

2 gives in addition, a balance sheet is produced for each fluid in place region defined with the FIPNUM keyword. This shows current and initial fluids in place.

WELLS Output of well (and groups) reports with production and injection rates and cumulative totals:

1 gives a report of well flows

2 gives a report of well and connection flows

ALLOC Generate the .alloc file. This file contains allocation factors and pore volumes (drainage area) for wells and for injector-producer pairs.

ALLOC=1 This report contains allocation factors and pore volumes (drainage area) for wells and for injector-producer pairs.

A .alloc file is generated.

ALLOC=2 This report contains all the information as for ALLOC=1, plus surface rates and volumes. This report is included in the .PRT file.

ALLOC=3 Same as for ALLOC=2 except that a separate .alloc file is generated.

302 Keywords FrontSim User GuideRPTSCHED

Example

RPTSCHEDFREQ=1 FIP=1 WELLS=2 ALLOC=1 /

FrontSim User Guide KeywordsRPTSLN

303

RPTSLN Controls on output to the SLN fileThis keyword provides control over which attributes are written to the SLN file, and therefore the size of the SLN files.

The keyword should be followed by a list of mnemonics that control the output of data. The list should be terminated by a slash (/).

For additional control over the output, integer values greater than one may be assigned to selected mnemonics using the syntax: mnemonic=integer

where there must be no spaces either side of the equals sign.

See also keyword RPTRST.


x FRONTSIMRUNSPECGRIDEDITPROPSREGIONS

x SOLUTIONSUMMARY

x SCHEDULE

Table 6.34 Controls on output to the SLN file

Keyword or Mnemonic Output

LINES[=VALUE]: Controls how many lines are output, overriding the STREAM setting on the RPTRST keyword, which is nevertheless retained for back compatibility. No streamlines at all are output if RPTSLN keyword is not present, and the STREAM mnemonic is set to 0 in the RPTRST keyword.

Default = 300

FREQ Controls which time steps the files are written at.

BASIC Gives attributes SWAT, SGAS, TIME_BEG, TIME_END, ID_BEG, ID_END.

FLOWS Gives attributes for flow rates.

FLOOIL: oil

FLOWAT: water

FLOGAS: gas

FLORES: reservoir fluid

UNITS: rm3/day (METRIC), rb/day (FIELD)

ALLOC Gives streamline scalar attributes for visualization of allocation data. Attributes are:

PFRACRES-reservoir fluid production fraction per streamline start point

PFRACOIL-oil production fraction per streamline start point

PFRACWAT-water production fraction per streamline start point

PFRACGAS-gas production fraction per streamline start point

IFRACRES reservoir fluid injection fraction per streamline end point

IFRACOIL-oil injection fraction per streamline end point

IFRACWAT-water injection fraction per streamline end point

IFRACGAS-gas injection fraction per streamline end point

NOADDLIN Added lines are not output to SLN files.

304 Keywords FrontSim User GuideRPTSLN

Example Gives SLN files containing 1000 streamlines, with output every third report step, containing all the available attributes.

RPTSLNLINES=1000 FREQ=3 BASIC FLOWS ALLOC /

FrontSim User Guide KeywordsRPTSOL

305

RPTSOL Controls output from SOLUTION sectionThe keyword should be followed by a list of mnemonics which control the output of SOLUTION section data to the initial restart (step 0) file. The list should be terminated by a slash (/).

For FrontSim, RESTART=2 can be used to create a step 0 restart file, or within a unified file.

Example


SPECIALx FRONTSIM



RPTSOLRESTART=2 /

306 Keywords FrontSim User GuideRS

RS Initial solution gas-oil ratiosThe keyword should be followed by one real number for every grid block, specifying the initial solution gas-oil ratio. The data field should be terminated by a slash (/).



This keyword is an alternative to the PBUB keyword for defining the initial dissolved gas distribution in runs with enumerated initial conditions.

See also the keywords PRESSURE, RV, PDEW, SWAT and SGAS in the SOLUTION section.



SPECIALx FRONTSIM



RS48*1.29 192*1.42 /

FrontSim User Guide KeywordsRSCONSTT

307

RSCONSTT Sets a constant Rs value for each dead oil PVT tableThe keyword is used to declare that the dead oil associated with each individual PVT table region contains a constant and uniform concentration of dissolved gas. This provides a more efficient way of modeling black oil systems in which there is no free gas and the pressure never falls below the bubble point.

The difference between this keyword and the ECLIPSE keyword RSCONST is that RSCONSTT allows the oil in different PVT table regions to have different Rs values. There must be no transmissibility between PVT table regions with different Rs values, to prevent oils with different Rs values from mixing. (If oil is allowed to flow between the regions, their Rs values change with time, and the reservoir must be modeled as live oil system with gas as an active phase.) Similarly, no well can be completed in two or more PVT table regions having different Rs values.

The flag for gas should not be switched on (keyword GAS in the RUNSPEC section), so that gas is not treated in the model as an active phase. The system therefore becomes a two-phase or single-phase model, depending on whether or not water is present as well as the oil. The oil should be treated as dead oil (using keyword PVDO to supply its PVT properties). PVT table regions are defined using keyword PVTNUM.

The keyword should be followed by one or more lines, one for each PVT table region.

Each line contains one or two items of data, terminated by a slash (/).:

Item 1: The dissolved gas concentration (Rs).

• UNITS: sm3/sm3 (METRIC), Mscf/stb (FIELD).Ignored by FrontSim Item 2: The bubble point pressure.





RSCONSTT0.37 /0.47 /

308 Keywords FrontSim User GuideRSVD

RSVD Rs versus depth tables for equilibrationThe data comprises one or more tables of dissolved gas-oil ratio versus depth, one for each equilibration region. Each table consists of 2 columns of data, and must be terminated by a slash (/).




Column 2: The corresponding values of Rs, the dissolved gas-oil ratio.


There must be the same number of entries in each column of a given table. This number should not be less than 2.

The entire table may be defaulted provided the table is not the first. Defaulted tables are replaced with a copy of the previous table.

This keyword is an alternative to the PBVD keyword, in which the bubble point pressure is tabulated against depth for each equilibration region. See also the keyword EQUIL.



SPECIALx FRONTSIM



RSVD7000 1.48000 1.4 /

FrontSim User Guide KeywordsRTEMP

309

RTEMP Initial reservoir temperatureThe RTEMP keyword is used to specify the initial reservoir temperature in runs where the Temperature option is active.

The keyword is followed by a single item of data, terminated with a slash (/):

Item 1: The reservoir temperature.

• UNITS: °C (METRIC), °F (FIELD).

See also keywords WTEMP and HEATCAP.

Example




RTEMP210 /

310 Keywords FrontSim User GuideRUNSUM

RUNSUM Requests tabulated output of SUMMARY data to separate fileThis keyword requests that the data in the Summary files should be tabulated in a separate RSM file at the end of the run. This is exactly the same form of output as is produced by GRAF using the Run Summaries option. The functionality is the same when using SEPARATE, the latter being supported for compatibility with ECLIPSE.

The operation of RUNSUM does not affect the data written to the summary files, which can still be used by GRAF in the usual manner.

The RUNSUM keyword has no associated data.

See also the keywords EXCEL and SEPARATE.

Example


SPECIALx FRONTSIM

RUNSPECGRIDEDITPROPSREGIONSSOLUTION

x SUMMARYSCHEDULE

RUNSUM

FrontSim User Guide KeywordsRV

311

RV Initial vapor oil-gas ratiosThe keyword should be followed by one real number for every grid block, specifying the initial vapor oil-gas ratio. The data field should be terminated by a slash (/).



This keyword is an alternative to the PDEW keyword for defining the initial vaporized oil distribution in runs with enumerated initial conditions.

See also the keywords PRESSURE, RS, PBUB, SWAT and SGAS in the SOLUTION section.



SPECIALx FRONTSIM



RV48*0.00725 48*0.00326 144*0 /

312 Keywords FrontSim User GuideRVCONSTT

RVCONSTT Sets a constant Rv value for each dry gas PVT tableThe keyword is used to declare that the dry gas associated with each individual PVT table region contains a constant and uniform concentration of vaporized oil. This provides a more efficient way of modeling gas condensate systems in which there is no free oil and the pressure never falls below the dew point.

The difference between this keyword and the ECLIPSE keyword RVCONST is that RVCONSTT allows the gas in different PVT table regions to have different Rv values. There must be no transmissibility between PVT table regions with different Rv values, to prevent gases with different Rv values from mixing. (If gas is allowed to flow between the regions, their Rv values change with time, and the reservoir must be modeled as wet gas system with oil as an active phase.) Similarly, no well can be completed in two or more PVT table regions having different Rv values.

The flags for oil should not be switched on (keyword OIL in the RUNSPEC section), so that oil is not treated in the model as an active phase. The system therefore becomes a two-phase or single-phase model, depending on whether or not water is present as well as the gas. The gas should be treated as dry gas (using keyword PVDG to supply its PVT properties). PVT table regions are defined using keyword PVTNUM.

The keyword should be followed by one or more lines, one for each PVT table region.

Each line contains two items of data, terminated by a slash (/):

Item 1: The vaporized oil concentration (Rv).


Item 2: The dew point pressure.

The run terminates if the pressure in any grid block in the PVT region falls below this value.


The keyword causes the gas density of each PVT region to be modified to include the vaporized oil, and causes the oil flow rate from each well to be set equal to its gas flow rate multiplied by the Rv value associated with the region in which it is completed. The group and field oil flows are obtained by summing the well oil flows.





RVCONSTT0.00047 330 /0.00057 350 /

FrontSim User Guide KeywordsRVVD

313

RVVD Rv versus depth tables for equilibrationThe data comprises one or more tables of vaporized oil-gas versus depth, one for each equilibration region.

Each table consists of 2 columns of data, and must be terminated by a slash (/).




Column 2: The corresponding values of Rv, the vaporized oil-gas ratio.

• UNITS: sm3/sm3 (METRIC), stb/Mscf (FIELD).

There must be the same number of entries in each column of a given table. This number should not be less than 2.

The entire table may be defaulted provided the table is not the first. Defaulted tables are replaced with a copy of the previous table.

This keyword is an alternative to the PDVD keyword, in which the dew point pressure is tabulated against depth for each equilibration region. See also the keyword EQUIL.



SPECIALx FRONTSIM



RVVD7000 0.007258000 0.00725 /

314 Keywords FrontSim User GuideSATNUM

SSATNUM Saturation function region numbers

The keyword should be followed by one integer for every grid block in the current input box specifying the saturation function region to which it belongs. The region number should not be less than 1. The data must be terminated by a slash (/).

The saturation function region number specifies which set of saturation functions (input using SGFN, SOF3, etc. in the PROPS section) should be used to calculate relative permeabilities and capillary pressures in each grid block.


See also the saturation function keywords SGFN, SWFN, SOF2, SOF3, SGOF and SWOF in the PROPS section.

ExampleWith NTSFUN=2, NDIVIX=8, NDIVIY=6, NDIVIZ=5 and no input BOX set:


SPECIALx FRONTSIM



SATNUM144*1 96*2 /

FrontSim User Guide KeywordsSCALECRS

315

SCALECRS Controls the end point scaling method The SCALECRS keyword is optional in runs with the End Point Scaling option active (keyword ENDSCALE in the RUNSPEC section). It is used to control the scaling method.

The keyword should be followed by one item of data, indicating whether the alternative scaling method is required, terminated with a slash (/):

either YES or NO

• DEFAULT: NO

The word may be shortened to Y or N.

In the default case, the scaling process preserves relative permeabilities at two saturation nodes. The following end points are assumed for each phase relative permeability:

Krw = SWCR and SWU

Krg = SGCR and SGU

Krow =SOWCR and (1.0-SWL-SGL)

Krog =SOGCR and (1.0-SWL-SGL)

The alternative form of scaling (if YES is specified) preserves the relative permeabilities at three saturation nodes. In 3-phase, oil-water or oil-gas runs, or runs that use the miscible flood option, the following end points are used:

Krw =SWCR, (1.0-SOWCR-SGL) and SWU

Krg =SGCR, (1.0-SOGCR-SWL) and SGU

Krow =SOWCR, (1.0- SWCR-SGL) and (1.0-SWL-SGL)

Krog= SOGCR, (1.0-SGCR-SWL) and (1.0-SWL-SGL)

In gas-water runs, the following end points are used if the second form of relative permeability scaling is selected:

Krw = SWCR, (1.0 -SGCR) and SWU

Krg = SGCR, (1.0-SWCR) and SGU

See "Saturation Table Scaling" in the "FrontSim Technical Description" for further details.

Example


SPECIALx FRONTSIM

RUNSPECGRIDEDIT


SCALECRSYES /

316 Keywords FrontSim User GuideSEPARATE

SEPARATE Requests run summary output to separate RSM fileThis keyword requests that the run summary output, generated by using the RUNSUM keyword, should be written to a separate file, rather than be appended to the end of the Print file. The separate run Summary file name is the root with the extension RSM.

It is possible to output the run summaries in a format suitable to be imported into a spreadsheet program such as Excel, by using the EXCEL keyword.

The SEPARATE keyword has no associated data.

Example


x FRONTSIMRUNSPECGRIDEDITPROPSREGIONSSOLUTION

x SUMMARYSCHEDULE

SEPARATE

FrontSim User Guide KeywordsSGAS

317

SGAS Initial gas saturationsThe keyword should be followed by one real number for every grid block specifying the initial gas saturation. The data field should be terminated by a slash (/).

This keyword may be used to specify the initial solution explicitly, as an alternative to equilibration using EQUIL. It is expected if the PRESSURE keyword is present, indicating explicit initialization.


Grid blocks are ordered with the X axis index cycling fastest (from 1 to NDIVIX), followed by the Y axis index (from 1 to NDIVIY), and finally the Z axis index (from 1 to NDIVIZ). Repeat counts may be used for repeated values (for example 115*0.18). Note that spaces may not be inserted on either side of the asterisk (*).

See also the keywords RS, PBUB, RV, PDEW and SWAT in the SOLUTION section.



SPECIALx FRONTSIM



SGAS48*0.448*0.0448*048*048*0 /

318 Keywords FrontSim User GuideSGCR

SGCR Scaled critical gas saturationsThis keyword specifies the critical gas saturation (that is the largest gas saturation for which the gas relative permeability is zero) within each grid cell. The free gas flow across each grid face is calculated from a transformed gas relative permeability curve obtained by linearly scaling the tabulated relative permeability data between the new critical gas saturation defined using an SGCR keyword, and the new maximum gas saturation (see under keyword SGU in the PROPS section). The SGCR keyword also permits scaling of the relative permeability table used in computing the flow of free gas between grid cells and well connections.

The SGCR keyword should not be used if gas is not present in the model. The keyword ENDSCALE should be specified in the RUNSPEC section.

The SGCR keyword should be followed by one real number for each grid block in the current input box specifying the critical gas saturation within the grid block. The saturation should be in the range 0.0 to 1.0 inclusive. The data must be terminated by a slash(/).


If the SGCR keyword is omitted in a model where it could be accepted then the critical gas saturation for a gas relative permeability calculation defaults to the value used in the appropriate relative permeability table.

See also keywords SGU, SGL, ENPTVD in the PROPS section.

Example


SPECIALx FRONTSIM

RUNSPECGRIDEDIT


----RUNSPEC sectionDIMENS1 7 3 /ENDSCALE/----PROPS section-------- IX1-IX2 JY1-JY2 KZ1-KZ2BOX

1 1 2 7 1 3SGCR5*0.04 10*0.03 3*0.05 /

FrontSim User Guide KeywordsSGFN

319

SGFN Gas saturation functionsThe data comprises one or more tables (see SATNUM) of gas saturation functions, each terminated by a slash (/).


Column 1: The gas saturation.

Values should be between 0 and 1 and should increase monotonically down the column.

Column 2: The corresponding gas relative permeability.

Values should be between 0 and 1 and should be level or increasing down the column. The first value in the column must be 0.

Column 3: The corresponding oil-gas capillary pressure.


Default values (represented by 1*) may be inserted as required in columns 2 and 3. When the table is read in, defaults are replaced by values computed by linear interpolation.

ExampleWith NTSFUN=2:


SPECIALx FRONTSIM

RUNSPECGRIDEDIT


SGFN.0000 .0000 0.0400 .0000 0.1000 .0220 0.2000 .1000 0.3000 .2400 1*.5000 .4200 1*.6000 .5000 0.7000 .8125 0.7800 1.0000 0/.00 .0000 0.12 .0220 0.22 .1000 0.32 .2400 0.52 .4200 0.62 .5000 0.72 .8125 0.80 1.0000 0/

320 Keywords FrontSim User GuideSGL

SGL Scaled connate gas saturationsThis keyword specifies the connate gas saturation (that is the smallest gas saturation in a gas saturation function table) within each grid cell.

The SGL keyword should not be used if gas is not present in the model. The keyword ENDSCALE should be specified in the RUNSPEC section.

The SGL keyword defines the new connate gas saturation for the equilibration procedure.

The SGL keyword should be followed by one real number for each grid block in the current input box specifying the connate gas saturation within the grid block. The saturation should be in the range 0.0 to 1.0 inclusive. The data must be terminated by a slash(/).


If the SGL keyword is omitted in a model where it could be accepted then the connate gas saturation for gas-oil defaults to the value used in the appropriate gas saturation function table.

See also keywords SGU and ENPTVD in the PROPS section.

Example


SPECIALx FRONTSIM

RUNSPECGRIDEDIT


----RUNSPEC sectionDIMSNS1 7 3 /ENDSCALE/-------- IX1-IX2 JY1-JY2 KZ1-KZ2BOX

1 1 2 7 1 3SGL5*0.0 10*0.02 3*0.0 /

FrontSim User Guide KeywordsSGOF

321

SGOF Gas/oil saturation functions versus gas saturationThe SGOF keyword may be used in runs containing both oil and gas as active phases, to input tables of gas relative permeability, oil-in-gas relative permeability and oil-gas capillary pressure as functions of the gas saturation. If water is also an active phase in the run, the water/oil saturation functions must be input with keyword SWOF.

The data comprises one or more tables (see SATNUM) of gas/oil saturation functions, each terminated by a slash (/).


Column 1: The gas saturation.

Values should be between 0 and 1 and should increase monotonically down the column. The first value in the column must be zero.

Column 2: The corresponding gas relative permeability.

Values should be between 0 and 1 and should be level or increasing down the column. The first value in the column must be zero.

Column 3: The corresponding oil relative permeability when oil, gas and connate water are present.

Values should be between 0 and 1 and should be level or decreasing down the column. If water is present in the run, the first value in the column (krog at Sg = 0) must be the same as the first value in the krow column in keyword SWOF (that is krow at So = 1 - Swco). The last value in the column must be zero.

Column 4: The corresponding oil-gas capillary pressure.


Default values (represented by 1*) may be inserted as required in columns 2, 3 and 4. When the table is read in, defaults are replaced by values computed by linear interpolation.

See also keywords STONE1 and STONE2.


SPECIALx FRONTSIM

RUNSPECGRIDEDIT


322 Keywords FrontSim User GuideSGOF

ExampleWith NTSFUN=2 and NSSFUN ≥ 10:

SGOF-- Sg Krg Krog Pcog

.0000 .0000 1.00 .0000

.0400 .0000 0.60 .2000

.1000 .0220 0.33 .5000

.2000 .1000 0.10 1.0000

.3000 .2400 0.02 1*

.4000 1* 0.00 1*

.5000 .4200 0.00 1*

.6000 .5000 0.00 3.0000

.7000 .8125 0.00 3.5000

.7800 1.0000 0.00 3.9000 / table 1

.00 .0000 1.00 0

.05 .0220 0.62 0

.2 .1100 0.12 0

.5 .4400 0.0 0

.6 .5600 0.0 0

.82 1.0000 0.0 0 / table 2

FrontSim User Guide KeywordsSGU

323

SGU Scaled saturation table maximum gas saturationsThis keyword specifies the maximum gas saturation (that is the largest gas saturation in a gas saturation function table) within each grid cell. The scaled maximum gas saturation is used to determine the scaled form of the gas relative permeability curves. A linear transformation is used to produce the scaled gas relative permeability curves using the new critical gas saturation (see keyword SGCR in the PROPS section) and the new maximum gas saturation defined using the SGU keyword. The scaled relative permeability curves are then used to compute the free gas flow out of each grid cell face, the free gas flow between grid cells and well connections and in the equilibration algorithm.

The SGU keyword should not be used if gas is not present in the model. The keyword ENDSCALE should be specified in the RUNSPEC section.

The SGU keyword should be followed by one real number for each grid block in the current input box specifying the maximum gas saturation within the grid cell. The saturation should be in the range 0.0 to 1.0 inclusive. The data must be terminated by a slash(/).


If the SGU keyword is omitted in a model where it could be accepted then the maximum gas saturation for relative permeability calculations defaults to the value used in the appropriate gas saturation function table.

See also keywords SGL, SGCR, ENPTVD in the PROPS section.

Example


SPECIALx FRONTSIM

RUNSPECGRIDEDIT



1 1 2 7 1 3SGU18*1.00 /

324 Keywords FrontSim User GuideSIGMA

SIGMA Dual porosity matrix-fracture couplingIf the Dual Porosity option is being used (by specifying the DUALPORO keyword in the RUNSPEC section), this keyword can be used to specify a multiplier to be used in the construction of the matrix-fracture coupling transmissibilities.

If this keyword is used, the sigma factor is applied to the entire grid.

This ‘sigma factor’ may be related to the matrix block size by the expression:

[EQ 6.37]

where , and are typical X, Y and Z dimensions of the matrix blocks.

The relationship was proposed by Kazemi (SPEJ Dec 76, 317-326) (see [Ref. 5] in the ECLIPSE Technical Description).

The dimensions of the matrix blocks used above are not the dimensions of the simulation grid, but of the elements of matrix material in the reservoir.

• UNITS: m-2 (METRIC), ft-2 (FIELD), cm-2

Alternatively, sigma may be treated as a simple history matching factor.

If neither SIGMA nor SIGMAV are specified then the default sigma factor is 0.0 throughout the grid.

ExampleUsing Kazemi's expression, in FIELD units, a value of 0.12 would correspond to 10 ft. matrix blocks.


SPECIALx FRONTSIM

RUNSPECx GRID


SIGMA0.12 /

σ 4 1lx2

---- 1ly2

---- 1lz2

----+ +⎝ ⎠⎜ ⎟⎛ ⎞

=

lx ly lz

FrontSim User Guide KeywordsSIGMAV

325

SIGMAV Dual porosity matrix-fracture couplingIf the Dual Porosity option is being used (keyword DUALPORO in the RUNSPEC section), this keyword can be used to specify a multiplier to be applied in the construction of the matrix-fracture coupling transmissibilities.

The keyword should be followed by one positive real number for every grid block in the current box within the top NDIVIZ/2 layers of the grid (that is, the matrix cells). Any values input in the bottom half of the grid (the lower NDIVIZ/2 layers) will be ignored.

This sigma factor may be related to the matrix block size by the expression:

[EQ 6.38]

where , and are typical X, Y and Z dimensions of the matrix blocks.

The relationship was proposed by Kazemi (SPEJ Dec. 76, 317-326) (see [Ref. 5] in the ECLIPSE Technical Description).

The dimensions of the matrix blocks used above are not the dimensions of the simulation grid.

• UNITS: m-2 (METRIC), ft-2 (FIELD), cm-2

Alternatively sigma may be treated as a simple history matching factor.

If neither SIGMA nor SIGMAV are specified then the default sigma factor is 0.0 throughout the grid.

When the SIGMA values are output the first NDIVIZ/2 layers are copied into the lower half of the grid.

Example

Using Kazemi’s expression, in FIELD units, a value of 0.12 would correspond to 10 ft matrix blocks.


SPECIALx FRONTSIM

RUNSPECx GRID


--------- IX1-IX2 JY1-JY2 KZ1-KZ2BOX

1 8 1 1 1 2 /SIGMAV0.12 0.12 0.12 0.12 0.12 0.12 0.12 0.121.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0 /

Σ 4 1lx

2----- 1

ly2

----- 1lz

2-----+ +

⎝ ⎠⎜ ⎟⎛ ⎞

=

lx ly lz

326 Keywords FrontSim User GuideSKIPREST

SKIPREST Skip subsequent keywords until the restart timeThe SKIPREST keyword has no associated data. It instructs FrontSim to skip the subsequent keywords in the SCHEDULE section of a restart run until the restart time has been reached. This saves you from having to delete the keywords yourself. It should normally be placed at the very start of the SCHEDULE section.

Note It is recommended that the keyword is the first one in the SCHEDULE section.

The keyword has no effect in the base run (starting from time zero), but in a restart run it causes FrontSim to reset the simulation time to zero and skip the subsequent keywords until a time-stepping keyword (for example, TSTEP or DATES) advances the simulation time to the restart time. Thereafter the keywords are read in as normal.

Not all keywords are skipped. Some keywords supply data that is not carried over on the restart file, such as

• Reservoir property keywords - boundaries, aquifers, and so on. Reservoir property keywords - boundaries, aquifers, and so on: AQUFLUX, FLUXSIDE, PNODE, PSIDE and PSIDEH.

• Simulation controls - output, tuning and so on: AQUFLUX, FLUXSIDE, PNODE, PSIDE, PSIDEH, FSSOLVE, FSWEAKW, GOCADOUT, GUIDERAT, MAXSTEP, NEXTSTEP, MINSTEP, TSCRITFS, OPTIONFS, RANKING, RPTLINFS, RPTPRINT, RPTRST, RPTSCHED, TUNEFS1D, TUNEFSPR, TUNEFSSA and WRFTPLT.

• Other keywords that need to specified: VFPPROD, VFPINJ, WELLSTRE, WINJGAS, WPIMULT, WTMULT, WSOLVENT, and WCONINJP.

These keywords must be present in the SCHEDULE section of the restart run, if they are needed in the run. Accordingly, FrontSim reads and process these keywords in the usual way, even if they occur between the SKIPREST keyword and the restart time. VFP tables should be entered before the first time-stepping keyword (it is best to place them at the start of the SCHEDULE section).

If the SKIPREST keyword is present in a restart run, take care to ensure that it is followed by the time-stepping keywords necessary to advance the simulation time from zero to the restart time. There must be a report step corresponding to the restart time, at which FrontSim stops skipping keywords and begins simulating normally. Thus, if the DATES keyword is used to advance the simulation, there must be a DATES record with a date identical to the restart date.

Example



x SCHEDULE

SKIPREST

FrontSim User Guide KeywordsSOF2

327

SOF2 Oil saturation functions (2-phase)The data comprises one or more tables (see SATNUM) of oil saturation functions, each terminated by a slash (/).


Column 1: The oil saturation.


Column 2: The corresponding oil relative permeability.


Note Default values (represented by 1*) are not allowed, and will give an error message as a result.



SPECIALx FRONTSIM

RUNSPECGRIDEDIT


SOF20 0.2 0.38 0.4 .004.48 .02.5 .036.58 .1.6 .146.68 .33.7 .42

.74 .60

.78 1.00 /

.0000 .0000

.2000 .0000

.3800 .0043

.4000 .0048

.4800 .0529

.5000 .0649

.5800 .1130

.6000 .1250

.6800 .3450

.7000 .4000

.7400 .7000

.7800 1.0000 /

328 Keywords FrontSim User GuideSOF3

SOF3 Oil saturation functions (3-phase)The data comprises one or more tables (see SATNUM) of oil saturation functions, each terminated by a slash (/).


Column 1: The oil saturation.

Values should be between 0 and 1 and should increase monotonically down the column. The maximum oil saturation should be equal to , where is the connate water saturation.

Column 2: The corresponding oil relative permeability for regions where only oil and water are present.


Column 3: The corresponding oil relative permeability for regions where only oil, gas and connate water are present.


The maximum values in columns 2 and 3 both represent the oil relative permeability at maximum oil saturation ( ) and should therefore have the same value.

Default values (represented by 1*) are not allowed, and will give an error message as a result.

See also keywords STONE1 and STONE2.

Note that SOF3 should be used only in three phase cases. In oil/gas and oil/water cases use SOF2.

ExampleWith NTSFUN=1 and NSSFUN ≥ 12:


SPECIALx FRONTSIM

RUNSPECGRIDEDIT


SOF3.0000 .0000 .0000.2000 .0000 .0000.3800 .0020 .0000.4000 .0048 .0015.4800 .0200 .0200.5000 .0649 .0700.5800 .0100 .1000.6000 .1250 .1200.6800 .3200 .3300.7000 .4000 .4000.7400 .7500 .6000.7800 1.0000 1.0000 /

1 Swco– Swco

So 1 Swco–=

FrontSim User Guide KeywordsSOGCR

329

SOGCR Scaled critical oil-in-gas saturations This keyword specifies the critical oil-in-gas saturation (that is the largest oil saturation for which the oil relative permeability is zero in an oil-gas-connate water system) within each grid cell. The oil flow across each grid face in an oil-gas-connate water system is calculated from a transformed oil-gas relative permeability curve obtained by linearly scaling the tabulated oil-gas relative permeability data between the new critical oil-in-gas saturation defined using an SOGCR keyword, and the new maximum oil saturation (see under the keywords SWL, SGL in the PROPS section). The SOGCR keyword also permits scaling of the oil-gas relative permeability table used in computing the flow of oil between grid blocks and well connections.

The SOGCR keyword should not be used if either oil or gas is absent from the model. The keyword ENDSCALE must be specified in RUNSPEC.

The SOGCR keyword should be followed by one real number for each grid block in the current input box specifying the critical oil-gas saturation within the grid block. The saturation should be in the range 0.0 to 1.0 inclusive. The data must be terminated by a slash(/).


If the SOGCR keyword is omitted in a model where it could be accepted then the critical oil-in-gas saturation for an oil relative permeability calculation defaults to the value used in the appropriate relative permeability table.

See also keywords SGL, SWL, ENPTVD in the PROPS section.

Example


SPECIALx FRONTSIM

RUNSPECGRIDEDIT



1 1 2 7 1 3SOGCR

5*0.24 10*0.21 3*0.20 /

330 Keywords FrontSim User GuideSOLVSLUG

SOLVSLUG Solvent slug allocationThis keyword is part of the IOR scale-up option. It describes solvent allocation functionality.

Each record is terminated by a slash.

Record 1For MI allocation

1 TARGSSZ: Global target solvent slug size fraction for each injector.


• DEFAULT: No default

2 MINSSZ: Global minimum solvent slug size fraction for each injector.



3 MAXSSZ: Global maximum solvent slug size fraction for each injector.



4 MINWAG: Global minimum WAG ratio for each injector. The minimum allowed ratio of injected water to injected solvent.

This parameter is presently not implemented within SLMODE=2 mode.

It is used to bound the WAG ratio when excess solvent is redistributed to wells each time the WAG ratio needs to be referenced.


5 TARGWAG: Global target WAG ratio target for the year; the ratio of injected water to injected solvent in record 2 only. Note that the actual WAG ratio is defined in the WAG_CATEGORY keyword.


6 MIRCYCLE: Global reservoir miscible injection recycle factor for each injector. Fraction of produced solvent that is re-injected into the reservoir.

• UNITS: Real number in the range [0.0, 1.0]


Record 2WAG ratio assignment table.

This record is only used with SLMODE=2.

1 TARGWAG: Target WAG ratio during solvent allocation; it is the ratio of injected water to injected solvent (record 2 only).



x SCHEDULE

FrontSim User Guide KeywordsSOLVSLUG

331

This is a look-up table to determine the specific WAG ratio for an injector, based on the accumulated percentage of solvent injected (see third column of the record). The sequence to allocate slug size for each injector is defined in the RANKWELL keyword.


2 MINWAG: Minimum required WAG ratio.

This is used to bound the WAG ratio when excess solvent is redistributed to wells each time the WAG ratio needs to be referenced.


3 MIFRAC: The available fraction of solvent at a specific TARGWAG ratio. The sum of this column should add up to 1.0 in a given table.

• UNITS: Fraction


Example

Note It is possible to adjust the amount of unused portion of solvent supply by adjusting the percentage MIFRAC and target WAG injection ratio TARGWAG in Record 2.

SOLVSLUG-- Record 1: -- TARGSSZ MINSSZ MAXSSZ MINWAG TARGWAG MIRCYCLE

0.07 0.07 0.08 0.20 1.00 0.85 /-- Record 2:-- TARGWAG MINWAG MIFRAC

0.0 0.5 0.301.0 0.5 0.402.0 1.0 0.203.0 2.0 0.104.0 2.0 0.005.0 2.0 0.006.0 2.0 0.00 /

332 Keywords FrontSim User GuideSOWCR

SOWCR Scaled critical oil-in-water saturations This keyword specifies the critical oil-in-water saturation (that is the largest oil saturation for which the oil relative permeability is zero in an oil-water system) within each grid cell. The oil flow across each grid face in an oil-water system is calculated from a transformed oil-water relative permeability curve obtained by linearly scaling the tabulated oil-water relative permeability data between the new critical oil-in-water saturation defined using an SOWCR keyword, and the new maximum oil saturation (see under keywords SWL, SGL in the PROPS section). The SOWCR keyword also permits scaling of the oil-water relative permeability table used in computing the flow of oil between grid cells and well connections.

The SOWCR keyword should not be used if either oil or water is absent from the model. The keyword ENDSCALE should be specified in RUNSPEC.

The SOWCR keyword should be followed by one real number for each grid block in the current input box specifying the critical oil-water saturation within the grid block. The saturation should be in the range 0.0 to 1.0 inclusive. The data must be terminated by a slash(/).


If the SOWCR keyword is omitted in a model where it could be accepted, then the critical oil-in-water saturation for an oil relative permeability calculation defaults to the value used in the appropriate relative permeability table.

See also keywords SGL, SWL, ENPTVD in the PROPS section.

Example


SPECIALx FRONTSIM

RUNSPECGRIDEDIT



1 1 2 7 1 3SOWCR5*0.21 10*0.19 3*0.18 /

FrontSim User Guide KeywordsSSHIFT

333

SSHIFT Equation of state shift parameters In a run with components, this keyword specifies volume shift parameters in dimensionless form. The use of these shift parameters is described in "Equations of State" in the "FrontSim Technical Description". This shift parameter can be applied to any equation of state.

Note FrontSim handles only a single EoS region.

Example


SPECIALx FRONTSIM

RUNSPECGRIDEDIT


-- 3-Parameter EoS Shift CoefficientsSSHIFT-0.07361 -0.15427 -0.05559 -0.02573 -0.08493 -0.16602 /

Nc

334 Keywords FrontSim User GuideSTART

START Specifies a start dateThis keyword specifies the start date of the simulation. (Any report dates entered in the DATES keyword in the SCHEDULE section must be later than the start date.) The keyword is followed by 3 items of data, denoting the day, month and year of the start of the simulation, terminated with a slash (/).

1 Day: Day of the month (an integer between 1 and 31).

2 Month: Name of the month abbreviated to three characters (JAN, FEB, MAR, APR, MAY, JUN, JLY, AUG, SEP, OCT, NOV, DEC). JUL is an acceptable alternative to JLY.

3 Year: The year (a 4-figure integer).

4 Time

The time (24 hour, in the format HH:MM:SS.SSSS)

• DEFAULT: 1 Jan 1900 00:00:00

Example




START12 FEB 1987 06:00:00 /

FrontSim User Guide KeywordsSTCOND

335

STCOND Specify standard conditionsIn compositional runs, a standard temperature and pressure must be specified. This used to obtain surface gas volumes at stock tank conditions. The keyword should be followed by two data items terminated with a slash (/):

1 Standard temperature

• UNITS: °C (METRIC), °F (FIELD)

2 Standard pressure

• UNITS: barsa (METRIC), psia (FIELD

Example


SPECIALx FRONTSIM

RUNSPECGRIDEDIT


STCOND60 14.65 /

336 Keywords FrontSim User GuideSTONE1

STONE1 Request Stone three-phase oil relative permeability modelThis keyword, which has no associated data, is used to specify that the three-phase oil relative permeability values are to be calculated using the modified Stone’s formula number 1. The STONE1 keyword should only be used in three-phase runs.

If neither the STONE1 or STONE2 keywords are present in the PROPS section of the input data file, the default 3-phase oil relative permeability model is used.

See "Saturation Table Scaling" in the "FrontSim Technical Description" for a description of three-phase oil relative permeability models available.

Example


SPECIALx FRONTSIM

RUNSPECGRIDEDIT


STONE1

FrontSim User Guide KeywordsSTONE2

337

STONE2 Request Stone three-phase oil relative permeability modelThis keyword, which has no associated data, is used to specify that the three-phase oil relative permeability values are to be calculated using the modified form of Stone’s model number 2. The STONE2 keyword should only be used in three-phase runs.

If neither the STONE1 or STONE2 keywords are present in the PROPS section of the input data file, the default 3-phase oil relative permeability model is used.

See "Saturation Table Scaling" in the "FrontSim Technical Description" for a fuller description of the three-phase oil relative permeability models available.

Example


SPECIALx FRONTSIM

RUNSPECGRIDEDIT


STONE2

338 Keywords FrontSim User GuideSWAT

SWAT Initial water saturationsThe keyword should be followed by one real number for every grid block specifying the initial water saturation. The data field should be terminated by a slash (/).

Grid blocks are ordered with the X-axis index cycling fastest (from 1 to NDIVIX), followed by the Y-axis index (from 1 to NDIVIY), and finally the Z-axis index (from 1 to NDIVIZ). Repeat counts may be used for repeated values (for example 115*0.22). Note that spaces may not be inserted on either side of the asterisk (*).

This keyword may be used to specify the initial solution explicitly, as an alternative to equilibration using EQUIL. It is expected if the PRESSURE keyword is present, indicating explicit initialization, and if a water phase is present.



SPECIALx FRONTSIM



SWAT48*048*0.0448*0.248*0.748*1 /

FrontSim User Guide KeywordsSWATINIT

339

SWATINIT Initial water saturations for capillary pressure scalingThis keyword allows you to input a water distribution and to scale the water-oil capillary pressure curves such that this water distribution is honored in the equilibrated initial solution. Note that any water saturation value that cannot be honored because it is below the water contact is reset to the maximum water saturation in the subsequent equilibration calculation.

This can be used to check for unphysically high maximum capillary pressures, which can be limited by using the PPCWMAX keyword.

The SWATINIT keyword may only be used if the end point scaling option is active (keyword ENDSCALE in the RUNSPEC section).

The keyword should be followed by one real number for every grid block in the current input box, specifying the required water saturation. The data field should be terminated by a slash (/).

Grid blocks are ordered with the X-axis index cycling fastest (from 1 to NDIVIX), followed by the Y-axis index (from 1 to NDIVIY), and finally the Z-axis index (from 1 to NDIVIZ). Repeat counts may be used for repeated values (for example 115*0.22). Note that spaces must not be inserted on either side of the asterisk (*).

See also the PCW and PPCWMAX keywords in the PROPS section and the EQUIL keyword in the SOLUTION section.

Further information can be found in "Matching initial water distribution" in the "ECLIPSE Technical Description".

Notes• If a grid block is given a water saturation less than 1.0 below the oil water contact (where

Pc=0), then the SWATINIT saturation is not honored.

• If a cell is given saturation corresponding to a zero capillary pressure (typically 1.0) above the contact, then the Pc curve cannot be scaled to honor the saturation, hence the Pc curve is left unscaled.

• If the SWATINIT saturation is less than or equal to the connate saturation for a cell, the capillary pressure is not scaled.

• The SWATINIT saturation may not be exactly honored if the fine grid block equilibration option is used in the EQUIL keyword.

• If the PCW keyword has been used, then this is ignored in regions where SWATINIT is set.

• If the Leverett J-function calculation for the water-oil capillary pressure has been activated through the JFUNC keyword, then J-function calculation is ignored in regions where SWATINIT is set.

• The SWATINIT saturation is not honored if the capillary pressure curve is a constant. The input capillary pressure curve needs to be monotonically decreasing with increasing water saturation.


SPECIALx FRONTSIM

RUNSPECGRIDEDIT

X PROPSREGIONSSOLUTIONSUMMARYSCHEDULE

340 Keywords FrontSim User GuideSWATINIT


SWATINIT120*0120*0.1120*0.5120*0.7120*1 /

FrontSim User Guide KeywordsSWCR

341

SWCR Scaled critical water saturationsThe different forms of this keyword specify the critical water saturation (that is the largest water saturation for which the water relative permeability is zero) within each grid cell. The water flow across each grid face is calculated from a transformed water relative permeability curve obtained by linearly scaling the tabulated relative permeability data between the new critical water saturation defined using an SWCR keyword, and the new maximum water saturation (see under keyword SWU in the PROPS section). The SWCR keyword also permits scaling of the relative permeability table used in computing the flow of water between grid cells and well connections.

The SWCR keyword should not be used if water is not present in the model. The keyword ENDSCALE should be specified in the RUNSPEC section.

The SWCR keyword should be followed by one real number for each grid block in the current input box specifying the critical water saturation within the grid block. The saturation should be in the range 0.0 to 1.0 inclusive. The data must be terminated by a slash(/).


If the SWCR keyword is omitted in a model where it could be accepted then the critical water saturation for a water relative permeability calculation defaults to the value used in the appropriate relative permeability table.

See also keywords SWU, SWL, ENPTVD in the PROPS section.

Example


SPECIALx FRONTSIM

RUNSPECGRIDEDIT


----RUNSPEC sectionDIMENS1 7 3 /ENDSCALE/-------- IX1-IX2 JY1-JY2 KZ1-KZ2BOX

1 1 2 7 1 3SWCR5*0.22 10*0.17 3*0.19 /

342 Keywords FrontSim User GuideSWFN

SWFN Water saturation functionsThe data comprises one or more tables (see SATNUM) of water saturation functions, each terminated by a slash (/).


Column 1: The water saturation.


Column 2: The corresponding water relative permeability.

Values should be between 0 and 1 and should be level or increasing down the column.

The first value in the column must be 0.

Column 3: The corresponding water-oil capillary pressure.

Values should be level or decreasing down the column.

Default values (represented by 1*) may be inserted as required in columns 2, and 3. When the table is read in, defaults are replaced by values computed by linear interpolation.

Note If the saturation tables contain values of Pcow not equal to zero for any value of Sw FrontSim automatically equilibrates, taking account of the capillary pressure. It also activates the end point scaling feature and sets the connate water in all cells in the oil water transition zones to the maximum of the connate water in that cell and the initial water saturation. This is done so that the initial solution is in equilibrium.



SPECIALx FRONTSIM

RUNSPECGRIDEDIT


SWFN.2200 .0000 0.3000 .0700 0.4000 .1500 0.5000 .2400 1*.6000 .3300 0.8000 .6500 0.9000 .8300 1*1.0000 1.0000 0 /.18 .00 0.32 .07 0.50 .31 0.60 .38 0.80 .57 01.00 1.00 0 /

FrontSim User Guide KeywordsSWL

343

SWL Scaled connate water saturationsThis keyword specifies the connate water saturation (that is the smallest water saturation in a water saturation function table) within each grid cell.

The SWL keyword should not be used if water is not present in the model. The keyword ENDSCALE should be specified in the RUNSPEC section.

The SWL keyword defines the new connate water saturation for the equilibration procedure.

The connate water saturation entered using SWL is used to scale the oil relative permeability curves.

The SWL keyword should be followed by one real number for each grid block in the current input box specifying the connate water saturation within the grid block. The saturation should be in the range 0.0 to 1.0 inclusive. The data must be terminated by a slash(/).


See also keywords SWU and ENPTVD in the PROPS section.

Example


SPECIALx FRONTSIM

RUNSPECGRIDEDIT



1 1 2 7 1 3SWL5*0.22 10*0.17 3*0.19 /

344 Keywords FrontSim User GuideSWOF

SWOF Water / oil saturation functions versus water saturationThe SWOF keyword may be used in runs containing both oil and water as active phases, to input tables of water relative permeability, oil-in-water relative permeability and water-oil capillary pressure as functions of the water saturation.

The data comprises one or more tables (see SATNUM) of water/oil saturation functions, each terminated by a slash (/).


Column 1: The water saturation.


The first value in the column is interpreted as the connate water saturation.

Column 2: The corresponding water relative permeability.

Values should be between 0 and 1 and should be level or increasing down the column.

The first value in the column must be zero.

Column 3: The corresponding oil relative permeability when only oil and water are present.

Values should be between 0 and 1 and should be level or decreasing down the column.

The last value in the column must be zero.

Column 4: The corresponding water-oil capillary pressure.

Values should be level or decreasing down the column.

Default values (represented by 1*) may be inserted as required in columns 2, 3 and 4. When the table is read in, defaults are replaced by values computed by linear interpolation.

Note If the saturation tables contains values of Pcow not equal to zero for any value of Sw FrontSim automatically equilibrates, taking account of the capillary pressure. It also activates the end point scaling feature and sets the connate water in all cells in the oil water transition zones to the maximum of the connate water in that cell and the initial water saturation. This is done so that the initial solution is in equilibrium.


SPECIALx FRONTSIM

RUNSPECGRIDEDIT


FrontSim User Guide KeywordsSWOF

345


SWOF-- Sw Krw Krow Pcow

.2200 .0000 1.0000 0

.3000 .0700 0.4000 0

.4000 .1500 0.1250 0

.5000 1* 0.0649 1*

.6000 .3300 0.0048 0

.8000 .6500 0.0 0

.9000 .8300 0.0 1*1.0000 1.0000 0.0 0 / table 1.18 .00 1.00 0.32 .07 0.38 0.50 .31 0.05 0.60 .38 0.004 0.80 .57 0.0 01.00 1.00 0.0 0 / table 2

346 Keywords FrontSim User GuideSWU

SWU Scaled saturation table maximum water saturationsThis keyword specifies the maximum water saturation (that is the largest water saturation in a water saturation function table) within each grid cell. The scaled maximum water saturation is used to determine the scaled form for the water relative permeability curve. A linear transformation is used to produce the scaled water relative permeability curves using the new critical water saturation (see keyword SWCR in the PROPS section) and the new maximum water saturation defined using an SWU keyword. The scaled relative permeability curves are then used to compute the water flow out of each grid cell face, the water flow between grid cells and well connections and in the equilibration algorithm.

The SWU keyword should be not used if water is not present in the model. The keyword ENDSCALE should be specified in the RUNSPEC section.

The SWU keyword should be followed by one real number for each grid block in the current input box specifying the maximum water saturation within the grid cell. The saturation should be in the range 0.0 to 1.0 inclusive. The data must be terminated by a slash(/).


If the SWU keyword is omitted in a model where it could be accepted then the maximum water saturation for relative permeability calculations defaults to the value used in the appropriate water saturation function table.

See also keywords SWL, SWCR, ENPTVD in the PROPS section.

Example


SPECIALx FRONTSIM

RUNSPECGRIDEDIT



1 1 2 7 1 3SWU18*1.00 /

FrontSim User Guide KeywordsTABDIMS

347

TTABDIMS Table dimensions


Note This keyword is accepted but ignored/not used by FrontSim.

1 NTSFUN: The number of saturation tables entered using SGFN and so on in the PROPS section. (Different saturation tables may be used in different parts of the reservoir - see SATNUM in the REGIONS section.)

• DEFAULT: 1

2 NTPVT: The number of PVT tables entered using PVTG, PVTO and so on in the PROPS section. (Different PVT tables may be used in different parts of the reservoir - see PVTNUM in the REGIONS section.)

• DEFAULT: 1

3 NSSFUN: The maximum number of saturation nodes in any saturation table. (See SGFN, SGOF and so on in the PROPS section.

ECLIPSE 100 • DEFAULT: 20ECLIPSE 300 • DEFAULT: 50

4 NPPVT: The maximum number of pressure nodes in any PVT table (PVTG, PVTO, PVDG, PVDO and so on), or in any rock compaction table.

ECLIPSE 100 • DEFAULT: 20ECLIPSE 300 • DEFAULT: 50

5 NTFIP: The maximum number of FIP regions defined using FIPNUM in the REGIONS section.

• DEFAULT: 1

6 NRPVT: ECLIPSE 100 The maximum number of Rs nodes in a live oil PVT table (PVTO) or Rv nodes in a wet gas

PVT table (PVTG). ECLIPSE 300 The maximum number of Rs nodes in a live oil PVT table (PVTO).

• DEFAULT: 20 ECLIPSE 300 only 7 NRPVT: The maximum number of Rv nodes in a wet gas PVT table (PVTG).

• DEFAULT: 20

8 NTENDP: The maximum number of saturation end-point versus depth tables is specified.

• DEFAULT: 1ECLIPSE 300 only 9 The maximum number equation of state regions for reservoir conditions.

• DEFAULT: 1

ECLIPSE 300 only 10 The maximum number equation of state regions for surface conditions.

• DEFAULT: Value in item 9.

11 The maximum number of flux regions.

• DEFAULT: 10




348 Keywords FrontSim User GuideTABDIMS

ECLIPSE 300 only 12 The maximum number of thermal regions.

• DEFAULT: 1ECLIPSE 300 only 13 The maximum number of rock tables.

• DEFAULT: number of pressure tablesECLIPSE 300 only 14 The maximum number of pressure maintenance regions.

• DEFAULT: 0

ECLIPSE 300 only 15 The maximum number of temperature dependent K-value tables. (Thermal option only)

• DEFAULT: 1

ExampleTwo saturation and pressure tables with 50 nodes in each table.

TABDIMS2 2 50 50 /

FrontSim User Guide KeywordsTAD

349

TAD Adsorption function for tracerSets an adsorption function for a tracer. The adsorption is given as a function of the tracer concentration.

The actual keyword to be used is a concatenated name of up to 7 characters in length, which consists of the following segments:

Segment 1: Characters 1-3 must be the character string TAD

Segment 2: Character 4 must be S (simple solvent) or N (“xnorm”).

Segment 3: Characters 5-7 must be the name of the tracer.



1 Concentration, increasing values.

• UNITS: fraction

2 Adsorption value, increasing values.

• UNITS: fraction

After the last values there may be an optional record IRREVERSIBLE.

Examples

Example 1

Simple, irreversible tracer T1:

Example 2

The effective solvent adsorption isothermBy definition, there is a one-to-one relationship between the amount of mobilized IOR oil at each point on a streamline and the amount of effective solvent that is trapped. In a typical case, the maximum amount of IOR oil that can be mobilized is . The parameter denotes the residual oil after water flooding, whereas denotes the residual oil after miscible injection. The adsorption isotherm for the effective solvent is linear, as shown in Figure 6.7.




TADST10.00000 0.00000 /0.20000 0.00400 /0.40000 0.00700 /0.60000 0.00900 /0.80000 0.01000 /1.00000 0.01050 /IRREVERSIBLE //

Sorw Sorm– Sorw

Sorm

350 Keywords FrontSim User GuideTAD

Figure 6.7 Adsorption isotherm for effective solvent

The adsorption isotherm is entered into FrontSim with TADNT1.

Here, the ‘T1’ at the end of TADNT1 refers to tracer number 1, which is the effective solvent. IRREVERSIBLE indicates that the solvent cannot be re-mobilized. In each row, the first value is the concentration , normalized by the sum at the current cell, and the second value is the adsorption term. In this example, , and denotes the maximum possible IOR oil concentration that may be recovered.

Example 3

The ineffective solvent adsorption isothermWe have set the amount of effective solvent trapping to be equal to the mobilized IOR oil. However, the amount of total solvent trapping in truth models typically exceeds the amount of mobilized IOR oil. This additional solvent trapping is handled by the ineffective-solvent adsorption isotherm. Its sole purpose is to add any additional trapping that might be required to match the total solvent trapping that is seen in the truth model. A linear adsorption isotherm is used as shown in Figure 6.8, where the concentration is again normalized by the sum at the current cell.

Figure 6.8 Adsorption isotherm for ineffective solvent

Trapped (adsorbed)effective solvent

TADNT1 0.0 0.00 / 1.0 0.24 / IRREVERSIBLE //

C1 C1 C3+

Sorw Sorm– 0.24=

C3 C1 C3+

Trapped (adsorbed) ineffective solvent

Vary slope of adsorption curve for ineffective solvent until total trapped solvent matches Truth Model

FrontSim User Guide KeywordsTAD

351

The adsorption isotherm is entered into FrontSim with TADNT3.

Here, the ‘T3’ at the end of TADNT3 refers to tracer number 3, which is the ineffective solvent. In each row, the first value is the concentration and the second value is the adsorption. In this case, a maximum trapped saturation of 3% is used.

BackgroundTracers, or polymers, may be added to the injected phase to investigate reservoir properties as well as for defining flow patterns and inter-well connections. Due to physical and chemical interaction between added species (tracers) and the porous medium, adsorption takes place. The most important effects are due to ion exchange, ion pairing and hydrophobic bonding mechanisms. The relative importance of these effects depend highly on the tracer as well as the porous medium. Most minerals in reservoirs have a negative electric potential (although some clays have positive). Thus, to minimize electrostatic effects most non-neutral tracers are negative ions. Also the pH value is critical for the adsorption. In general, decreased pH value (fewer H+ ions in the solute) allows more positive potential on the rock surface, and thereby increases adsorption of a negative tracer species.

Due to the numerous combined effects, the adsorption function may have different shapes, even non-convex. However, for most purposes a relatively simple mathematical model for adsorption is used, the Langmuir model.

The underlying assumption for this model is a reversible exchange of tracer at the rock surface. The following mathematical model is used:

[EQ 6.39]

Here:

= concentration in fluid phase

= adsorbed amount of tracer

= maximum adsorbed amount of tracer

= reaction coefficient for adsorption

= reaction coefficient for de-adsorption

Several options are possible for the units for the adsorbed amount. Mass of tracer per mass of rock is frequently used.

If we assume that the time scale for the adsorption process is short compared to the time scales of interest in reservoir simulation, we may assume that equilibrium is established instantaneously. Thus, the above equation gives:

[EQ 6.40]

TADNT3 0.0 0.00 / 1.0 0.03 /IRREVERSIBLE //

t∂∂ a c( ) k1c A a c( )–( ) k2a c( )–=

c

a c( )

A

k1

k2

a c( )k1Ac

k1 k2Ac+-----------------------=

352 Keywords FrontSim User GuideTAD

which is the Langmuir model for adsorption.

In Figure 6.9 we see a typical shape of the function.Figure 6.9 Langmuir model

For adsorption processes, hysteresis is also an important effect. Anything between no hysteresis and complete irreversible adsorption may occur, and may complicate the modeling to some extent.

For the one-phase tracer model in <ProductName>FrontSim, the adsorption is used explicitly to compute the tracer shock speed. The conservation law for the tracer is:

[EQ 6.41]

where v is the flow velocity. Thus, the shock speed of a tracer shock (separating and ) is given by

[EQ 6.42]

In the present version of the code, hysteresis is accounted for by assuming that if present, the adsorption is irreversible. Thus, in the above expression, in case of irreversibility (IRREVERSIBLE), the immobile concentrations and are determined not by the actual floating concentrations, but by the maximum value ever obtained at the actual location. The adsorbed tracer distribution is updated globally after each time step.

a(c)

c

t∂∂ c a c( )+( ) vc( )∇+ 0=

cL cR

σcR cL–

cR a cR( ) cL– a cL( )–+-------------------------------------------------------v=

a cL( ) a cR( )

FrontSim User Guide KeywordsTADE

353

TADE Adsorption - IOR tracerSet target values for an IOR tracer.

The actual keyword is a concatenated name of up to 7 characters in length, which consists of the following segments:

Segment 1: Characters 1-4 must be the character string TADE

Segment 2: Characters 5-7 must be the name of the tracer.

1 IOR target

• UNITS: fraction

• DEFAULT: 0

2 Net solvent target.

• UNITS: fraction

• DEFAULT: 0

Note This keyword should be used together with TADN (“xnorm” tracer). See keyword TAD.

Examples

Example 1

Example 2

Adsorption parameters for IOR oilThe initial amount of trapped (adsorbed) IOR oil is set by the TADE keyword with the following syntax:

ADS 1.0 /

where ADS = volume of trapped IOR oil per pore volume =

Here, the ‘T2’ at the end of TADET2 refers to tracer #2, which is the IOR oil. In this case, the trapped IOR oil = Sorw-Sorm = 24%. The value of 1.0 in the second column is a default value that should not be changed.




TADET10.4 1.0 /

TADET20.24 1.0 //

Sorw Sorm–

354 Keywords FrontSim User GuideTADE

It is also possible to specify the ADS value on a cell-by-cell basis by using the TIADS(T2) keyword. The individual cell values will then override the one defined by the TADET2 keyword.

Note This is the default way of setting up the initial concentration for trapped or adsorbed IOR oil. You usually do not need to do more to the initial IOR tracer model unless there are reasons to update the initial concentration of trapped IOR.

FrontSim User Guide KeywordsTBLK

355

TBLK Initial tracer concentrationsThe keyword specifies the initial concentration of a tracer in each grid block. The actual keyword to be used is a concatenated name of up to 8 characters in length, which consists of the following segments:

Segment 1: Characters 1-4 must be the character string TBLK

Segment 2: Character 5 must be the letter F.

FrontSim can only use F (free state)

Segment 3: Characters 6-8 must be the name of the tracer that is being initialized.

• UNITS: fraction

ExampleWhere NDIVIX=2, NDIVIY=3, NDIVIZ=3 and water phase tracer WT1:

NoteIt is possible to specify 0.0 trapped IOR targets in an aquifer layer or zone using the TIADS keyword.


SPECIALx FRONTSIM



TBLKFWT118*1.0 /

356 Keywords FrontSim User GuideTCRIT

TCRIT Critical temperaturesIn a run with components, this keyword associates a critical temperature with each component.



• UNITS: °K (METRIC), °R (FIELD).

Example


SPECIALx FRONTSIM

RUNSPECGRIDEDIT


TCRIT140 270 450 670 /

Nc

Nc

FrontSim User Guide KeywordsTHICKZ

357

THICKZ Layer thickness in z directionSets the thickness (depth difference) in the z direction between node pairs. The thickness is assumed to be along the z-axis, even in a non-planar grid. Must be preceded by keyword DEPTHZ, describing the top node depths.


ExampleHere NDIVIX = 4, NDIVIY = 3 and NDIVZ = 2.


x FRONTSIMRUNSPEC


DEPTHZ20*3000/

THICKZ20*1020*12/

358 Keywords FrontSim User GuideTHREADFS

THREADFS Set maximum number of threads for a FrontSim runThis keyword is used to set the maximum number of threads when running FrontSim on a Multi Core platform. This value could also be controlled by the licensing (number of multi core licenses available) - but it will give the user the opportunity to control how many processor FrontSim will execute on. The keyword should be followed by a integer. The list should be terminated by a slash (/).

1 Number of Threads - integer value > 0 and less than 65

• DEFAULT: = 1 or 2 depending on hardware (if the hardware is Dual Core - 2 threads are included as part of the Base FrontSim (Black Oil) license. This is new in 2008.1.)

Note To run FrontSim with multithreading - the explicit solver should always be selected (TUNEFS1D).

Note If the number of threads is bigger that the number processors (cores) that are available the machine - FrontSim gives a warning - but the simulation will continue.

Example


x FRONTSIMx RUNSPEC


THREADFS-- the simulation is set up to run with 4 threads (cores)4 /

FrontSim User Guide KeywordsTIADS

359

TIADS Initial tracer adsorbedThe actual keyword to be used is a concatenated name of up to 8 characters in length, which consists of the following segments:

Segment 1: Characters 1-5 must be the character string TIADS

Segment 2: Character 6-8 must be the name of the tracer.

The keyword should be followed by one non-negative real number for every grid block in the current input box.

Sets the initial tracer adsorption of each cell in a grid. Otherwise it is set according to the initial tracer concentration and adsorption curve.

• UNITS: Fraction

ExampleHere NDIVIX = 4, NDIVIY = 4 and NDIVZ=2. The tracer name is T1.


x FRONTSIMRUNSPECGRIDEDITPROPSREGIONS


TIADST132*0.2527 /

360 Keywords FrontSim User GuideTITLE

TITLE Specify run titleThis enables a run title to be set up, which will be included in the Print file headers. The syntax is rather different from that of other keywords, the line after the TITLE keyword being read directly. No quotes or slash characters are required.

Example




TITLEFifth run in series - increased production rate

FrontSim User Guide KeywordsTPAIRS

361

TPAIRS Tracer pair lookup tableThis keyword is part of the IOR scale-up option. It defines the master-slave tracer relationship, master being adsorption and slave being desorption.

TPAIRS has two arguments, terminated by a slash (/).

TMASTER: The name of the master tracer. Restricted to three characters.

TSLAVE: The name of the slave tracer. Restricted to three characters.

ExampleFor tracer names up to T9:

NoteThere are three options when defining the IOR tracer logic.

• Line 1 defines MWAG logic

• Line 2 defines IWAG before MWAG logic (which requires Line 1)

• Line 3 defines IWAG after MWAG logic (which requires Line 1, 2 and 3).

In other words, MWAG logic requires tracer T1, T2, T3. IWAG before MWAG requires T1, T2, T3, T4, T5, T6, and finally IWAG after MWAG requires all the 9 reserved IOR tracer.




TPAIRS-- TMASTER TSLAVE

T1 T2 --Defines MWAG logicT1 T5 --

Defines IWAG before MWAG logic. Requires MWAG logicT7 T8 --

Defines IWAG after MWAG logic. Requires IWAG before MWAG logic/

362 Keywords FrontSim User GuideTPFA

TPFA Fraction of pore volume flooded by the tracerSets the accessible pore volume for each tracer in the whole reservoir. The value is used to scale the velocity of the tracer front. The actual keyword to be used is constructed as a concatenation of the four-letter string TPFA and the tracer name. The tracer name is restricted to three characters.

Segment 1: Characters 1-4 must be the character string TPFA

Segment 2: Character 5-7 must be the name of the tracer.

TPFA has one argument, terminated by a slash (/).

V - Accessible pore-volume fraction. The value is assigned to the whole reservoir for the tracer. Must be a positive real number greater than 0.0.

• UNITS: Fraction

• DEFAULT: 1.0

ExampleIf the tracer name is T1:




TPFAT10.21 /

FrontSim User Guide KeywordsTPFV

363

TPFV Fraction of pore volume flooded by the tracer by cellSets the accessible pore volume for each tracer in the whole reservoir. The values are used to scale the velocity of the tracer front. The actual keyword to be used is constructed as a concatenation of the four-letter string TPFV and the tracer name. The tracer name is restricted to three characters.

TPFV has one argument, terminated by a slash (/).

V1... VN: Accessible pore-volume fractions. Must be positive real numbers greater than 0.0.

• UNITS: Positive real numbers

• DEFAULT: 1.0

ExampleGiven the tracer name T1 and a reservoir of 100 cells:




TPFVT130*0.03 70* 0.02 /

364 Keywords FrontSim User GuideTPVT

TPVT Tracer PVTThis keyword is part of the IOR scale-up option. It defines the PVT properties for IOR tracers.

The TPVT keyword can also be used to set the volume factors for gas in the 2-phase IOR model. These volume factors are used to convert from surface to reservoir conditions when using WCONINJE with gas and also WCONHIST for production. The user should be aware that this is strictly just to help compute proper reservoir volumes for injection and production. There is no real gas phase in the model, and the injection will be converted to water in the current version of the FrontSim tracer extension model. GAS is associated with the recycled lean gas injected; this gas was previously produced from the reservoir. Refer to the MIRCYCLE parameter in keyword SOLVSLUG.

TPVT has four arguments, terminated by a slash (/).

TNAME The name of the tracer. Must not exceed three characters. Currently T1 and T3 are IOR gas tracers and T2 is an IOR oil tracer.

• DEFAULT: none

BINJ Formation volume factor for the corresponding tracer for an injection well. For solvent and lean-gas tracers, BINJ = Bg of injected gas. For IOR oil tracer, BINJ is not used since oil is never injected.

• UNITS: rm3/sm3 (METRIC), RB/Mscf (FIELD)

• DEFAULT: none

BPROD Formation volume factor for the corresponding tracer for a production well. For solvent and lean-gas tracers, BPROD = Bg of produced gas. For IOR oil tracer, BPROD is Bo of produced IOR oil.

• UNITS: For gas tracers: rm3/sm3 (METRIC), RB/Mscf (FIELD)

For oil tracers: rm3/sm3 (METRIC), RB/stb (FIELD)

• DEFAULT: none

RSIOR Solution gas/oil ratio from IOR oil. This parameter is needed only for T2; for other tracers it takes the default value.

• UNITS: sm3/RB (METRIC), Mscf/stb (FIELD)

• DEFAULT: 0.0




FrontSim User Guide KeywordsTPVT

365

ExampleFor tracer names GAS, T1, T2 and T3, up to tracer T9:

Note The GAS tracer listing is required for certain reports given by the facility limit logic. The GAS tracer should be treated in the same way as lean gas tracer (T4). The use of GAS tracer is no longer necessary for releases from FrontSim 2003A upwards.

TPVT--TNAME BINJ BPROD RSIOR

GAS 0.8500 0.8500 0.00 –-Same as other lean gas type tracers required for the Facility Logic reporting

T1 0.7490 0.7490 0.00T2 1.2450 1.2450 0.60T3 0.7490 0.7490 0.00 --Same as T1, or MI solvent tracer

--T4 0.8500 0.8500 0.00 –-Second type of tracers are the lean gas tracer--T5 0.8500 0.8500 0.00--T6 0.8500 0.8500 0.00--T7 0.8500 0.8500 0.00--T8 0.7490 0.7490 0.00 --Same as T1/T3, or MI solvent tracer--T9 0.8500 0.8500 0.00/

366 Keywords FrontSim User GuideTRACER

TRACER Set up tracersThis keyword sets up a number of passive tracers, associating each of them with a particular fluid used in the study.

The keyword should be followed by one line for each tracer introduced. Each line must contain the data items listed below, and is terminated by a slash (/). The set of records must end with a blank record, containing only a slash (/)

1 Tracer name: (Up to 3 characters)

2 The name of the fluid associated with the tracer:

FrontSim OIL, WAT or TOT (oil+water).

Note Tracers are not available in 3-phase runs.

Example


SPECIALx FRONTSIM

RUNSPECGRIDEDIT


TRACERT1 TOT /T2 TOT //

FrontSim User Guide KeywordsTRANX

367

TRANX X-direction transmissibility valuesThis keyword specifies the transmissibility values explicitly, replacing those calculated by the program. The TRANX keyword applies to transmissibilities in the X-direction.

The keyword should be followed by one non-negative real number for every grid block in the current input box. The data must be terminated by a slash (/).

The TRANX values specified overwrite the X-direction transmissibilities calculated for the +X face of each grid block. Thus, a value specified for block (I, J, K) is the transmissibility between blocks (I, J, K) and (I+1, J, K).

• UNITS: METRIC: cP-rm3/day/bar, FIELD: cP-rb/day/psi


Note TRANX does not affect non-neighbor connections due to faults.

The TRANX keyword is entirely optional. Any transmissibilities that are not altered remain at the values calculated from the GRID data.

Example


SPECIALx FRONTSIM

RUNSPECGRID


-- IR1-IR2 JT1-JT2 KZ1-KZ2BOX

5 5 3 8 4 6 /TRANX18*0 /

368 Keywords FrontSim User GuideTRANY

TRANY Y-direction transmissibility valuesThis keyword specifies the transmissibility values explicitly, replacing those calculated by the program. The TRANY keyword applies to transmissibilities in the Y-direction.


The TRANY values specified overwrite the Y-direction transmissibilities calculated for the +Y face of each grid block. Thus, a value specified for block (I, J, K) is the transmissibility between blocks (I, J, K) and (I, J+1, K).



Note TRANY does not affect non-neighbor connections due to faults.

The TRANY keyword is entirely optional. Any transmissibilities that are not altered remain at the values calculated from the GRID data.

Example


SPECIALx FRONTSIM

RUNSPECGRID



1 4 3 3 4 6 /TRANY12*0 /

FrontSim User Guide KeywordsTRANZ

369

TRANZ Z-direction transmissibility valuesThis keyword specifies the transmissibility values explicitly, replacing those calculated by the program. The TRANZ keyword applies to transmissibilities in the z-direction.


The TRANZ values specified overwrite the Z-direction transmissibilities calculated for the +Z face of each grid block. Thus, a value specified for block (I, J, K) is the transmissibility between blocks (I, J, K) and (I, J, K+1).



Note TRANZ does not affect non-neighbor connections due to faults.

The TRANZ keyword is entirely optional. Any transmissibilities that are not altered remain at the values calculated from the GRID data.

Example


SPECIALx FRONTSIM

RUNSPECGRID



1 11 1 19 7 7 /TRANZ209*0 /

370 Keywords FrontSim User GuideTREFFIC

TREFFIC Table of IOR mobilization curvesTable of IOR mobilization curve data derived from the truth model studies. Truth models are typically compositional sector models that simulate the true WAG displacement physics in the field. Mobilization curves are then used at WAG injectors to quantify the physics using the injection tracer efficiency.

Each row defines one curve, where the NAME parameter uniquely identifies each mobilization curve. The identification allows assignment of specific mobilization curves to given injectors or injector perforation completions.

The parameters are obtained from a separate procedure; see the separate user document for obtaining such parameters (contact your local ECLIPSE representative for a copy).


1 NAME: The name of the mobilization curve. The name is referred to in other keywords.

• RESTRICTIONS: The name must not exceed eight characters.

• DEFAULT: None

2 A: IOR curve fitting parameter which describes the amount of IOR oil mobilized as a function of solvent slug size (SSZ) at fixed injection rate (FLDRTE). Note that this parameter will depend on the choice of the reference volume for normalization (VREF).

• DEFAULT: None

3 B: IOR curve fitting parameter which describes the amount of IOR oil mobilized as a function of solvent slug size (SSZ) at fixed injection rate (FLDRTE). Note that this parameter will depend on the choice of the reference volume for normalization (VREF).

• DEFAULT: None

4 C: IOR curve fitting parameter which describes the amount of IOR oil mobilized as a function of solvent slug size (SSZ) at fixed injection rate (FLDRTE). Note that this parameter will depend on the choice of the reference volume for normalization (VREF).

• DEFAULT: None

5 FLDRTE: The flood rate used to obtain the mobilization curve coefficients A, B, C. This curve should be typical to the model region it is being applied to. The unit is a fraction of total pore volume per year.

Enter a value of 0.1 for a rate of 10% TPV/YEAR

• UNITS: fraction of TPV/YEAR.

• DEFAULT: None

6 TPV: This is total volume quantity for the truth model associated with a FULL injector. Thus, if the injector-producer truth model simulations are done on a ¼ pattern, the value to enter on this line is 4 times the TPV of the ¼ pattern simulation.


• DEFAULT: None.




FrontSim User Guide KeywordsTREFFIC

371

7 VREF: VREF is the reference volume. used to normalize both the IOR oil and solvent slug size (SSZ) when fitting the A, B, and C parameters. In the original formulation of the IOR logic, VREF was required to be DEPV. In the new formulation, the reference value can be chosen by the user. The VREF volume is in RB, and is associated with a FULL injector. Thus, if the A, B, and C parameters were calibrated on a ¼ pattern model, then one should compute VREF from the ¼ pattern model, multiply it by 4, and enter that value on the TREFFIC keyword line.

For further discussion on the use of the multiplication factor (in this case, 4) please refer to the "Terms" on page 371.


• DEFAULT: None.

8 THK: Average thickness of IOR wells obtained in the calibration truth model.

THK = 0.0 indicates no scaling of THK in the truth model (internal THKRATIO=1.0).


• DEFAULT: None

9 D: IOR curve fitting parameter that describes the amount of IOR oil mobilized as a function of injection rate at fixed solvent slug size (SSZ).

• UNITS: None

• DEFAULT: None

10 E: IOR curve fitting parameter that describes the amount of IOR oil mobilized as a function of injection rate at fixed solvent slug size (SSZ).

• UNITS: None

• DEFAULT: None

11 F: IOR curve fitting parameter that describes the amount of IOR oil mobilized as a function of injection rate at fixed solvent slug size (SSZ).

• UNITS: None

• DEFAULT: None

12 SSZ: The solvent slug size expressed as a fraction of VREF, used to obtain coefficients D, E, F.

• UNITS: Fraction of VREF

• DEFAULT: None.

Terms

Full InjectorIn the IOR scale-up model a full injector is one in which flow emanates essentially radially in all directions away from the injector. A half-well is one in which the flow emanates in only a half-circle -- for example if an injector backs-up to a sealing fault. To minimize CPU time, the 2D vertical cross-section studies are typically done on partial-pattern models. For example, a ¼ of a five-spot pattern might be modelled rather than a full five-spot. To understand how the pattern type impacts the reservoir volume variable for the mobilization curve, consider the following example.

372 Keywords FrontSim User GuideTREFFIC

Give a ¼ pattern injector-producer pair, if 10 BBLS are injected, the front (R) will be computed from . If the 2-D cross-sectional study was done on a full five-spot (and therefore a FULL injector) and 10 BBLS were injected, then the flood front will be computed from with no 0.25 multiplier.

As you can see, if one solves for R in both cases, you will get a different value for the flood front location even though both simulations had 10 BBLS injected. Correct scaling requires that the flood-front location be the same between the injector-producer pair in the cross-section model and that in the actual field simulation. For this reason, we warn you “if the injector-producer simulations are done on a quarter pattern, the value to enter on this line is 4 times the VREF of the ¼ pattern simulation”. You might be modeling a simple 2-well quarter of a five-spot in which case there would be no multiplication involved. Thus, you must determine the multiplication factor on a case-by-case basis.

Calibration ProcedureSome of the parameters referred to in the IOR scale-up model keywords (PRODLIM, RANKING, RANKWELL, SOLVSLUG, TPAIRS, TPVT, TREFFIC) are based on a separate simulation study. The study requires a compositional simulator. The procedure is based on a 2D cross section compositional sensitivity simulation of IOR oil due to the use of various solvent slug sizes. The study cannot be done using the current version of FrontSim. This procedure is referred to as the calibration procedure in the keyword descriptions.

Note The mobilization curves, etc., are basically proportional sweep-out curves, so one could enter analytic estimates (from the Stiles method, for example, or from standard gas-sweep out versus mobility-ratio curves) in cases where it is not feasible to run the 2D cross-sections.

EOR = Enhanced Oil Recovery = IOR = Improved Oil Recovery

MWAG Miscible Water Alternating Gas

IWAG Immiscible Water Alternating Gas

IWAG/MWAG IOR injection start with IWAG stop with MWAG

IWAG/MWAG/IWAG IOR injection starts with IWAG, continues with MWAG and stops with IWAG.

Examples

Example 1

Vol 10 0.25 Height× π× R2×= =

Vol 10 Height π× R2×= =

TREFFIC -- NAME A B C FLDRTE TPV VREF THK D E F SSZ

c1 2.40 0.87 1.0 0.52e-2 10.4e06 2.6e06 80 3.5 0.76 900 0.23c2 2.00 0.90 1.0 0.50e-2 10.4e06 2.6e06 90 3.5 0.76 900 0.20c3 2.00 0.90 1.0 0.55e-2 10.4e06 2.6e06 0 3.5 0.76 900 0.20

/

FrontSim User Guide KeywordsTREFFIC

373

Example 2

Notes1 The TPV and VREF values will always be proportional to the truth model values.

where

and AOF = angle-open-to-flow of the injector.

Generally, injectors in the field have an AOF of 100% unless they back up to a sealing fault. However, truth model simulations are frequently done on quarter-pattern models (injector AOF = 25%). When simulating the field case in FrontSim, one should enter a VREF value on the TREFFIC keyword that is 4 times the truth model value ( ).

Consider another case, where the truth model is a quarter-pattern and we want to reference it with a simple injector-producer quarter-pattern IOR simulation model. The AOF is 25% in both cases, so . When simulating this quarter-pattern in FrontSim, you should enter a VREF value on the TREFFIC keyword that is equal to the Truth Model value. VREF is ultimately determined by the truth model configuration, and by its relationship to a particular injection pattern in the IOR tracer model.

2 TPV, VREF and THK are global parameters that can be overridden by the similar parameter in the RANKWELL keyword, specified for each injector. This step is often needed to scale the truth model to a tracer injector.

3 The TREFFIC keyword is required to activate tracer logic for both the history and the prediction modes.

TREFFIC-- NAME A B C FLDRTE TPV VREF THK D E F SSZMobCrv1 2.4 0.87 1.0 0.52e-2 10.4e06 2.6e06 0.0 3.5 0.76 900. 0.23

/

VREF αVREFTRUTHMODEL=

αAOFFIELD

AOFTRUTHMODEL----------------------------------------------=

α 4.0=

α 1.0=

374 Keywords FrontSim User GuideTSCRITFS

TSCRITFS Describes user control of time stepping algorithmTSCRITFS sets limiting parameters for automatic generation of time steps by FrontSim. The options are more likely to be useful for prediction runs. The criteria used by FrontSim for time stepping control are based on fluid volume change, pore volume throughput, pressure change, and flux variation.

The data consists of up to 4 items, terminated with a slash (/). Items defaulted (*) will be turned OFF. See also the "FrontSim Technical Description"

Note TSCRITFS is a FrontSim keyword only. Time step control concepts for streamline simulators are different from finite difference simulators.

1 MXFVCHG: Limits the maximum model phase fluid volume change (difference between source and sink flows) to be MXFVCHG fraction of the total pore volume during a timestep. The value is in the range from 0 to 1.

• UNITS: none.

• DEFAULT: OFF.

Note Any number larger than 1 resets the value to 0.1.

2 MXTHRUPT: Limits the maximum pore volume throughput to be the MXTHRUPT fraction of the total pore volume. The value is in the range from 0 to 1.

• UNITS: none.

• DEFAULT: OFF.

Note Any number larger than 1 resets the value to 0.1.

3 MXDELPA: Limits the maximum change of model average pressure to be the MXDELPA fraction of the average pressure at the start of the time step.

• UNITS: none

• DEFAULT: OFF

Note Any number larger than 1.0 resets the value to 0.1.

4 MXFLUXCHG: MXFLUXCHG scales the difference between model average cell flux and model throughput. The value is in the range from 0 to 1.

• Units: None

• DEFAULT: OFF.

Any number larger than 1.0 will reset the value to 0.1. Actual flux step control is effective one time step after this parameter is supplied. This method is intended for expert users.Please contact support for further guidance on how to use this option.

5 PAR5: For future use.

6 PAR6: For future use.



x SCHEDULE

FrontSim User Guide KeywordsTSCRITFS

375

7 DELPCONV: DELPCONV is used to redo the pressure solver with smaller timestep if the pressure solver does not converge. The new timestep is calculated as DELPCONV*dt, where dt was the previously attempted timestep. FrontSim continues to cut the timestep until pressure solver converge or timestep is equal to minimum timestep (MINSTEP). Acceptable range for DELPCONV is between 0 and 1. Recommended value is 0.2.

• Units: None

• DEFAULT: OFF.

8 MXPA: MXPA limits the maximum change of average pressure within the timestep to MXPA.

• Units: barsa (METRIC), psia (FIELD)

• DEFAULT: OFF.

Note Any number larger than 0.0 sets the limit to that value. In addition, activation of this method overrides the fractional change of pressure limit in the third parameter.

Examples

Example 1Using fluid volume change, pore volume throughput and flux time stepping controls.

In the time step computed the maximum change in the fluid volume for any phase is within 5% of the total pore volume and the pore volume throughput is within 15% of the total pore volume.

Example 2

Using pressure controlIn the time step computed the change in average field pressure will be within 2% of the field average pressure at the current time.

Example 3 Using the internal default for fluid volume change and Flux time stepping.

The effective limits for both the fluid volume and flux is reset to 0.1.

TSCRITFS-- MXFVCHG MXTHRUPT MXDELPA MXFLUXCHG /

0.05 0.15 1* 0.1 /


1* 1* 0.02 /


2.0 1* 1* 2.0/

376 Keywords FrontSim User GuideTSCRITFS

Example 4In this example a pressure solver non-convergence results in a new attempt to solve the pressure with 20% of the timestep until convergence is met or timestep limited by the minimum timestep.

TSCRITFS-- MXFVCHG MXTHRUPT MXDELPA MXFLUXCHG PAR5 PAR6 DELPCONV/

1* 1* 1* 1* 2* 0.2 /

FrontSim User Guide KeywordsTSTEP

377

TSTEP Advances simulator to new report time(s)The keyword should be followed by real numbers, each of which is a time interval through which the simulator is to be advanced.

The data should be terminated with a slash (/).

• UNITS: days.

After each time step a report of the current state of the reservoir is produced.

Note that repeat counts (for example 6*30.5) can be used if required (but no spaces before or after the asterisk).

Example


SPECIALx FRONTSIM


x SCHEDULE

TSTEP31 28 31 30 31 3031 31 30 31 30 31 /

378 Keywords FrontSim User GuideTUNEFS1D

TUNEFS1D Tuning options for the 3-phase 1D solverThis keyword replaces FSTUNE1D.

This keyword sets the tuning options for the 1D solver used on streamlines for 3-phase and compositional runs.

Note Items 1, 2, 3 and 8 cannot be changed during the run. These items should be set once before the first time step. Any subsequent attempt to change these parameters will be ignored. All the other parameters may be changed between timesteps. The values set will apply to all subsequent timesteps until the value is changed by another use of the keyword.

1 Method: 1D solver method/mode used on the streamlines.

During the simulation, it is only possible to switch between FULLIMP and EXPL.

a Alternative methods:

FULLIMP (Fully Implicit)

IMPES (Implicit Pressure Explicit Saturation)

AIM (Adaptive Implicit Method)

EXPL (Explicit Finite Difference Method)

• DEFAULT: EXPL for 3-phase models, and Front Tracker for 2 phase models

2 Nstreamlines: Max number of streamlines calculated simultaneously in a single call to the 1D solver. (This can only be set once.)

• DEFAULT: 100

• Not used in EXPL method.

3 Ncells: Max total number of cells used in the 1D solver (shared by multiple streamlines). (This can only be set once.)

• DEFAULT: 1000


4 MinDt: Min sub-timestep (fraction of global timestep).

• DEFAULT: 0.1

5 MaxDt: Max sub-timestep (fraction of global timestep).

• DEFAULT: 1.0

6 PFactor: This item only has an effect if item 7 of OPTIONFS is greater than zero. The pressure is taken to be a linear combination of the pressure obtained by frontsim prior to calculating the streamlines Pgrid and the pore volume weighted average of the pressures in the streamline cells after the saturation solve Pstream. The pressure at the end of the time step is taken to be:

Pgrid*(1-PFactor)+Pstream*PFactor

• DEFAULT: 0.0




x SCHEDULE

FrontSim User Guide KeywordsTUNEFS1D

379

7 Debug: For debugging, set this to 1, which gives more output to the console from the 1D solver.

• DEFAULT: 0 (Off)

8 MemoryMult: Allows the user to increase the memory allocated in the 3 phase saturation solver. This replaces item 9 in OPTIONFS. (This can only be set once.)

• DEFAULT: 1


9 MinCells: Min number of cells in the 1D solver for a single streamline.

• DEFAULT: 5

10 MaxCells: Max number of cells in the 1D solver for a single streamline.

• DEFAULT: 100

11 NCellsMult: Multiplier for the number of cells in the 1D solver, relative to the number of points representing the streamline in 3D. However, the number of cells is constrained by the min/max limits.

• DEFAULT: 0.5

12 MaxNewt: Sets the maximum number of Newton iterations in the saturation solver. This replaces item 12 in OPTIONFS.

• DEFAULT: 6


Example

TUNEFS1DIMPES 200 4000 /

380 Keywords FrontSim User GuideTUNEFSPR

TUNEFSPR Sets simulator control parametersThis keyword sets the tuning options for the pressure solver.

The keyword should be followed by the data items described below, terminated with a slash. Default values can be specified before the slash by a null repeat count of the form n*, where n is the number of consecutive items to be defaulted.

1 Frequency of pressure recalculations.

A recalculation of pressure is done with this frequency step of the simulation.

Set the frequency very high, for example to 10E23, to turn it off.

• DEFAULT: 1 (Every report step)

Note It is not recommended to set the frequency higher than 1 for cases with gravity segregation turned on. In such cases FrontSim will then override the frequency with 1This override behavior can be turned off by setting parameter 6 equal to 1 in keyword OPTIONFS.

Note The pressure is solved if FrontSIm detects that the rate is changed between the timesteps. For example, this will be the case when the rate is reallocated between the wells when the target is set at the group level. In this case, FrontSim solves pressure with frequency of 1

2 XXXMBE Maximum material balance error

• DEFAULT: 0.02

3 XXXCNV Maximum non-linear convergence error

• DEFAULT: 1E-4

4 XXXLCV Maximum linear convergence error

• DEFAULT: 1E-5

5 NEWTMX Maximum number of Newton iterations in a timestep

• DEFAULT: 1 (incompressible)

• DEFAULT: 3 (compressible)

6 LITMAX Maximum number of linear iterations in a Newton iteration

• DEFAULT: Calculated

Example



x SCHEDULE

TUNEFSPR1 0.02 1* 1* 2 10 /

FrontSim User Guide KeywordsTUNEFSSA

381

TUNEFSSA Tuning options for the saturation solverThis keyword sets the tuning options for the saturation solver.

The keyword should be followed by the data items described below, terminated with a slash. Default values can be specified before the slash by a null repeat count of the form n*, where n is the number of consecutive items to be defaulted.

Note Items 3 and 4 cannot be changed during the run. They should be set once before the first time step. Any subsequent attempt to change them is ignored. All other parameters may be changed between timesteps. Values set apply to all subsequent timesteps until changed by another use of the keyword.

1 GravitySegregation: When set (non-zero), FrontSim includes the gravity effect in the saturation solver. ‘iterations’ is the number of sub-iterations in the saturation solver. If the time steps are very long or the phase densities are very different, such as with gas and oil, the iteration number may have to be increased to capture the segregation effect. Gravity segregation can be turned off by setting this parameter to 0.

• A negative value gives a recommended number (1).

• DEFAULT: 1

Note Although you can change the number of segregation steps within a run, it cannot be switched on and off during the run. That is, if the value is initially set to zero GravitySegregation is off for the whole run. If the value is not set initially to zero you should not try to set the value to zero later in the run.

2 StreamDens: Increases or decreases the number of streamlines used by the saturation solver. The number of streamlines used will be the default number computed by FrontSim multiplied by StreamDens. The CPU usage will increase approximately linearly with StreamDens. The quality of the solution of the saturation equation is dependent on the number of streamlines used, but the default number is generally sufficient. It might be necessary to increase the number of streamlines to capture the flow around barriers if the grid has many areas with no flow (inactive cells).

• DEFAULT: Computed by FrontSim based on number of active cells. The actual number is reported in the .prt file as the SLN density.

Note In 3-phase mode, reducing StreamDens to too small a value can cause the FrontSim pressure solver to fail.

Note When either of the next two parameters is set (non-zero), FrontSim uses streamline-to-streamline mapping of saturations or concentrations. This minimizes numerical dispersion in FrontSim. Be aware that this requires more memory and increased CPU time. It should not be used with Option 1 - GravitySegregation.



x SCHEDULE

382 Keywords FrontSim User GuideTUNEFSSA

3 StreammapNs: Activates streamline mapping. Number of streamlines stored in a cell as the basis for streamline-to-streamline mapping of saturations or concentrations.



4 StreammapNi: Activates streamline mapping. Number of sampling points on a streamline in one single cell.



5 Addlines: When set, FrontSim checks whether each cell has been visited by at least one streamline.

• DEFAULT: YES


7 FluxMult: This multiplier adjusts the threshold flux below which a streamline is terminated and above which a streamline is added with the Addlines option. See item 5 above.

• DEFAULT: 1.0

8 1*

9 StartType: Where to start the tracking of streamlines. Possible values: BOTH, INJ, PROD, CHOOSE (best choice is determined by the simulator at each step).

• DEFAULT: BOTH for compressible, INJ for incompressible.

Example

TUNEFSSA2 0.8 1* 1* YES NO 1* 1* 1* /

FrontSim User Guide KeywordsUNIFIN

383

UUNIFIN Indicates that input files are unified

This indicates that input files (for example RESTART files), which may be either multiple or unified, are unified. The default, if this keyword is not specified, is to use multiple (non-unified) files.


Note If the UNIFIN keyword is set the corresponding UNIFOUT keyword should also be set.




384 Keywords FrontSim User GuideUNIFOUT

UNIFOUT Multiple/Unified Output FilesThis keyword indicates that information to RESTART and SUMMARY files is to be unified. Instead of producing separate files for each timestep (default), these files are amalgamated into a single file of each type.


Note If the UNIFOUT keyword is specified on input, the corresponding UNIFIN keyword should also be set.




FrontSim User Guide KeywordsVCRIT

385

VVCRIT Critical volumes

In a run with components, this keyword associates a critical molar volume with each component. These critical volumes are used in setting up the Zudkevitch-Joffe equation of state and in correlations. They are also used in the Lorentz-Bray-Clark viscosity correlation, unless separate values are entered for this purpose using the VCRITVIS or ZCRITVIS keywords.


• UNITS: m3/kg.M (METRIC), ft3/lb.M (FIELD)

Example


SPECIALx FRONTSIM

RUNSPECGRIDEDIT


VCRIT1.473 5.529 /

Nc

386 Keywords FrontSim User GuideVCRITVIS

VCRITVIS Critical volumes for viscosity calculations In a run with components, this keyword associates a critical molar volume with each component, to be used for viscosity calculations only.

If VCRITVIS or ZCRITVIS is not entered, then values entered with VCRIT or ZCRIT are used.


The form of VCRITVIS is the same as that of VCRIT.

• UNITS: m3/kg.M (METRIC), ft3/lb.M (FIELD)


SPECIALx FRONTSIM

RUNSPECGRIDEDIT


Nc

FrontSim User Guide KeywordsVFPINJ

387

VFPINJ Inputs a VFP table for injection wellsThis is a table of BHP versus FLO and versus THP.

At least one table is needed if any of the injection wells require THP calculations. The VFPINJ keyword can only enter one table at a time, so if there is more than one table, each table must be entered under a separate VFPINJ keyword.

The table consists of the following records of data, each record terminated with a slash (/).

Record 1: Basic data for tableThe last three items may be defaulted, for back-compatibility with earlier versions.

1 Table number

2 Bottom hole datum depth for table.

Any difference between the bottom hole datum depth of the VFP table and the bottom hole datum depth of the wells that use the table is taken into account by a simple hydrostatic correction.


3 Definition of the flow rate variable FLO.

OIL: oil injection rate

WAT: water injection rate

GAS: gas injection rate

4 Definition of the fixed pressure values given in "Record 3:THP values" on page 388.Needed but ignored by FrontSim

THP: tubing head pressure

FrontSim does not accept anything other than THP.

• DEFAULT: THP

5 Unit convention of the VFP table.

METRIC, FIELD

If this item is present, FrontSim checks that the VFP table has the same unit convention as the run and issues an error message if they are not the same.

• DEFAULT: The same unit convention as the FrontSim run.

6 Definition of the tabulated quantity in the body of the table, records 4 onwards.Needed but ignored by FrontSim

BHP

Bottom hole pressure

FrontSim will not accept anything other than BHP.

• DEFAULT: BHP


SPECIALx FRONTSIM


x SCHEDULE

388 Keywords FrontSim User GuideVFPINJ

Record 2:FLO (flow rate) valuesEnter in ascending order, terminated with a slash (/).

Record 3:THP valuesEnter in ascending order, terminated with a slash (/).

If only one value is entered, the derivative of the BHP with respect to the THP is treated as unity.


Records 4 to NTHP+3NTHP successive records each containing the following items, and each terminated with a slash (/).

1 NT (THP value number).

2 BHP at 1st FLO value and NTth THP value.

3 BHP at 2nd FLO value and NTth THP value.

.......................................

NFLO+1

BHP at last FLO value and NTth THP value.

All combinations of NF = 1 to NFLO and NT = 1 to NTHP must be covered.

• UNITS: barsa (METRIC), psia (FIELD),

Example

Example 1VFP table for water injector, NFLO=5, NTHP=1:

UNITS: Volume rate: sm3/day (METRIC),

stb/day for oil or water, (FIELD),

Mscf/day for gas (FIELD),

VFPINJ1 7.00000E+03 WAT THP FIELD BHP /1.00000E+00 3.00000E+02 7.00000E+02 1.00000E+032.00000E+03 /1.00000E+03 /1 4.03999E+03 4.03423E+03 4.01346E+03 3.98903E+03

3.85537E+03/

FrontSim User Guide KeywordsVFPINJ

389

Example 2VFP table for gas injector, NFLO=5, NTHP=3:

VFPINJ2 7.00000E+03 GAS THP FIELD BHP /1.00000E+00 3.00000E+02 7.00000E+02 1.00000E+032.00000E+03/1.00000E+03 2.00000E+03 3.00000E+03/1 1.32484E+03 1.32300E+03 1.31556E+03 1.30626E+03

1.25098E+03/

2 2.74881E+03 2.74801E+03 2.74490E+03 2.74110E+032.71934E+03/

3 3.94062E+03 3.94000E+03 3.93761E+03 3.93471E+033.91830E+03/

390 Keywords FrontSim User GuideVFPPROD

VFPPROD Inputs a VFP table for production wellsThis is a table of BHP versus FLO, THP, WFR, GFR and ALQ, versus FLO where:

FLO: is the oil, liquid or gas production rate, or, in compositional mode, the hydrocarbon wet gas production or total molar rate.

WFR: is the water-oil ratio, water cut or water-gas ratio, or, in compositional mode, the water-wet gas ratio or water molar fraction.

GFR: is the gas-oil ratio, gas-liquid ratio or oil-gas ratio, or, in compositional mode, the hydrocarbon mean molecular weight.

ALQ: is a 5th variable that can be used to incorporate an additional look-up parameter, such as the level of artificial lift.

Any combination of these variable definitions can be used, as long as they do not become infinite during the simulation.

For example, an oil well may have

• FLO: oil or liquid rate, or, in compositional mode, the wet gas or molar rate.

• WFR: water-oil ratio or water cut, or, in compositional mode, the water-wet gas ratio or water molar fraction.

• GFR: gas-oil ratio or gas-liquid ratio, or, in compositional mode, the mean molecular weight.

A gas well should have:

• FLO: gas rate, or, in compositional mode, the wet gas or molar rate.

• WFR: water-gas ratio, or, in compositional mode, the water-wet gas ratio or water molar fraction.

• GFR: oil-gas ratio (in gas-water runs only one value = 0.0 is required). FrontSim If the RSCONSTT keyword is used, the variables must be

• FLO: oil or liquid rate

• WFR: water-oil ratio or water cut

• GFR: gas-oil ratio.FrontSIm If the RVCONSTT keyword is used, the variables must be

• FLO: gas rate

• WFR: water-gas ratio

• GFR: oil-gas ratio.

At least one table is needed if any of the production wells require THP calculations. The VFPPROD keyword can only enter one table at a time, so if there is more than one table, each table must be entered under a separate VFPPROD keyword.

The table consists of the following records of data, each record terminated with a slash (/).

Record 1:Basic data for tableThe last four items may be defaulted, for back-compatibility with earlier versions.

1 Table number


SPECIALx FRONTSIM


x SCHEDULE

FrontSim User Guide KeywordsVFPPROD

391

2 Bottom hole datum depth for table.

Any difference between the bottom hole datum depth of the VFP table and the bottom hole datum depth of the wells that use the table are taken into account by UNITS: m (METRIC), ft (FIELD)

3 Definition of the flow rate variable FLO in record 2.

OIL: Oil production rate

LIQ: Liquid (oil + water) production rate

GAS: Gas production rate

4 Definition of the water fraction variable WFR in record 4.

WOR: Water-oil ratio

WCT: Water cut (water-liquid ratio)

WGR: Water-gas ratio

5 Definition of the gas fraction variable GFR in record 5.

GOR: Gas-oil ratio

GLR: Gas-liquid ratio

OGR: Oil-gas ratio

6 Definition of the fixed pressure values given in record 3.Needed - but ignored by FrontSim

THP: Tubing head pressure

FrontSim will not accept anything other than THP.

• DEFAULT: THPNeeded - but ignored by FrontSim

7 Definition of the artificial lift quantity (ALQ) in record 6

• DEFAULT: ' ' (none or undefined)

8 Unit convention of the VFP table.

METRIC, FIELD: If this item is present, FrontSim checks that the VFP table has the same unit convention as the run and issues an error message if they are not the same.

• DEFAULT: The same unit convention as the FrontSim run

Needed - but ignored by FrontSim

9 Definition of the tabulated quantity in the body of the table, record 7 onwards.

BHP: Bottom hole pressure

FrontSim will not accept anything other than BHP.

• DEFAULT: BHP

Record 2:FLO (flow rate) valuesEnter in ascending order, terminated with a slash (/).

UNITS:

Volume rate: sm3/day (METRIC),

stb/day for oil or liquid (FIELD),

Mscf/day for gas (FIELD),


Record 3:THP valuesEnter in ascending order, terminated with a slash (/).

If only one value is entered, the derivative of the BHP w.r.t. the THP is treated as unity.

• UNITS: barsa (METRIC), psia (FIELD),

Record 4:WFR valuesEnter in ascending order, terminated with a slash (/).

If only one value is entered, the BHP is treated as independent of the water fraction.

Record 5: GFR valuesEnter in ascending order, terminated with a slash (/).

If only one value is entered, the BHP is treated as independent of the gas fraction.

Record 6:ALQ valuesEnter in ascending order, terminated with a slash (/).

If only one value is entered, the BHP is treated as independent of the artificial lift quantity.

Records 7 to NTHP*NWFR*NGFR*NALQ+6 NTHP*NWFR*NGFR*NALQ successive records each containing the following items, and each terminated with a slash (/).

1 NT (THP value number).

2 NW (WFR value number)

3 NG (GFR value number)

4 NA (ALQ value number)

5 BHP at

1st: FLO value

NTth: THP value

UNITS: sm3/sm3 (METRIC),

stb/stb for WOR or WCT (FIELD),

stb/Mscf for WGR (FIELD),

UNITS: sm3/sm3 (METRIC),

Mscf/stb for GOR or GLR (FIELD),

stb/Mscf for OGR (FIELD),

FrontSim User Guide KeywordsVFPPROD

393

NWth: WFR value

NGth: GFR value

NAth: ALQ value

6 BHP at

2nd: FLO value

NTth: THP value

NWth: WFR value

NGth: GFR value

NAth: ALQ value

.......................................

NFLO+4

BHP at last FLO value

NTth: THP value

NWth: WFR value

NGth: GFR value

NAth: ALQ value

All combinations of

NF = 1 to NFLO

NT = 1 to NTHP

NW = 1 to NWFR

NG = 1 to NGFR

NA = 1 to NALQ must be covered.

• UNITS for BHP: barsa (METRIC), psia (FIELD),


ExampleVFP table for producer, NFLO=5, NTHP=2, NWFR=1, NGFR=3, NALQ=1:

VFPPROD1 7.00000E+03 LIQ WCT GOR THP ' ' FIELD BHP / Basic data1.00000E+01 3.00000E+02 7.00000E+02 1.00000E+032.00000E+03 / 5 flow vals2.00000E+02 1.00000E+03 / 2 THP values0.0 / 1 WFR value1.00000E+00 2.00000E+00 4.00000E+00 / 3 GFR values0.0 / 1 ALQ value1 1 1 1 1.93199E+03 1.36585E+03 6.77031E+02 7.15261E+02

8.62436E+02 /2 1 1 1 2.73663E+03 2.73303E+03 2.75085E+03 2.77323E+03

2.90209E+03 /1 1 2 1 1.77471E+03 4.33035E+02 5.38422E+02 6.30479E+02

9.39472E+02 /2 1 2 1 2.51228E+03 2.38072E+03 2.35995E+03 2.26536E+03

2.28849E+03 /1 1 3 1 1.64735E+03 4.41989E+02 6.95286E+02 8.81634E+02

1.41797E+03 /2 1 3 1 2.46600E+03 1.78161E+03 1.80525E+03 1.85156E+03

2.04484E+03 /

FrontSim User Guide KeywordsWATER

395

WWATER Run contains water

This indicates that the run contains water as an active phase, whose saturation can vary.

The keyword has no associated data.x ECLIPSE 100x ECLIPSE 300



396 Keywords FrontSim User GuideWCONHIST

WCONHIST Observed rates for history matching wellsThis keyword is used in place of WCONPROD to set their observed flow rates.

The WCONHIST keyword is followed by any number of records, each containing the following items of data, and each terminated with a slash (/).

The set of records must end with a blank record, containing only a slash.



2 Open/shut flag for the well

OPEN Well open for production

SHUT Well completely isolated from the formation

• DEFAULT: OPEN

3 Control mode

ORAT Controlled by the observed oil rate (item 4)

WRAT Controlled by the observed water rate (item 5)

GRAT Controlled by the observed gas rate (item 6)

LRAT Controlled by the observed liquid rate (oil + water)

RESV Controlled by the reservoir fluid volume rate calculated from the observed phase flow rates

4 Observed oil production rate


• DEFAULT: 0.0

5 Observed water production rate


• DEFAULT: 0.0

6 Observed gas production rate


• DEFAULT: 0.0

7 Production well VFP table number

(see keyword VFPPROD)

Set to this to zero if you do not require THP to be calculated. If set>0, the well’s THP is calculated and reported

• DEFAULT: Initially zero, subsequently no change from previous value

8 Artificial lift quantity, for use in calculating the THP


Should be defaulted if you do not require THP to be calculated.

9 Observed tubing head pressure (THP)


SPECIALx FRONTSIM


x SCHEDULE

FrontSim User Guide KeywordsWCONHIST

397

Values entered here are only used for reporting purposes, to compare with the calculated THP.

Default this item if there is no observed values to enter


• DEFAULT: 0.0

10 Observed bottom hole pressure (BHP):

Values entered here are only used for reporting purposes, to compare with the calculated BHP.

Default this item if there is no observed values to enter


• DEFAULT: 0.0

Note This keyword is not supported in Compositional mode.

Notes1 When control by a surface rate is selected, FrontSim internally converts the specified

surface rate to the corresponding total reservoir rate using the pressures and saturations at the beginning of the time step, and controls the well using the total reservoir rate, as if the well were under RESV control.

If the pressures and saturations change significantly during the time step, the surface rates also change during the time step. If the discrepancy between the input and calculated surface rates is too large, you need to reduce the time step length: see keyword MAXSTEP. This however increases the CPU time required for the run.

2 The phase flow rates entered here are not treated as upper limits. If the well’s calculated water rate, for example, exceeds the observed value, the well does not automatically change control to WRAT. Apart from setting the rate target, the phase flow rates are only used for reporting in the SUMMARY file.

3 The BHP lower limit is automatically set to atmospheric pressure when the well is first declared a history matching well (the first time it appears in a WCONHIST keyword). This is to reduce the possibility of the well changing to BHP control before its productivity index has been properly matched. (Changing to BHP control at atmospheric pressure is a sign that the Kh or skin factor is very badly matched.) You can reset the BHP limit to any desired value with the keyword WELTARG after the first WCONHIST keyword in which the well appears. The well’s BHP limit is not changed by subsequent WCONHIST.

398 Keywords FrontSim User GuideWCONHIST

ExampleWCONHIST-- well open/ ctrl oil water gas VFP ALQ obs obs-- name shut mode rate rate rate tab THP BHP

PROD1 OPEN LRAT 2410 320 /PROD2 OPEN RESV 1970 725 /PROD3 OPEN RESV 1507 431 1808 2 0.0 321 2314 /

/

FrontSim User Guide KeywordsWCONINJ

399

WCONINJ Injection well control data, with no group controlThis keyword can be used to set individual control targets and limits for injection wells, but it is an early keyword that has since been superseded by the simpler keyword WCONINJE, which is recommended in place of this one. WCONINJ has been retained for back-compatibility with old data sets. It can also be used to supply individual re-injection and voidage replacement targets for injectors. But re-injection and voidage replacement can be performed with more flexibility by group injection control using keyword GCONINJE, which is recommended wherever possible. Injectors under group control should be specified with the keyword WCONINJE instead of this one. If used with GCONINJE the well allocation specified in item 7 is overridden by the group control.


Default values can be specified before the slash by null repeat counts of the form n*, where n is the number of consecutive items to be defaulted.




2 Injector type

OIL Oil injector

WATER Water injector

GAS Gas injector


OPEN Well open for injection


No other options for FrontSim.

• DEFAULT: OPEN

4 Control mode

RESV Controlled by reservoir fluid volume fraction (FrontSim)

BHP Controlled by BHP


5 1*


6 1*

7 Re-injection or voidage replacement fraction

• DEFAULT: 0.0Required but not used by FrontSim

8 1*

9 BHP target or upper limit


• DEFAULT: 1.0E5 psia, or 6895 barsa



x SCHEDULE

400 Keywords FrontSim User GuideWCONINJ

Example

WCONINJINJ1 GAS OPEN RATE -200 1* 0.5 GPRD 5000 1000 2 /INJ2 WAT OPEN RESV 1* 0.0 0.2 FVDG 4000 /INJ3 WAT OPEN RATE 500 3* 5000 /INJ4 WAT OPEN RESV 1* 1* 0.2 1* 4000 //

FrontSim User Guide KeywordsWCONINJE

401

WCONINJE Control data for injection wellsThe keyword is followed by any number of records, each containing the following items of data, and each terminated with a slash (/).

The records may be terminated early with a slash (/), the remaining items taking default values. Default values can be specified before the slash by a null repeat count of the form n*, where n is the number of consecutive items to be defaulted.

For further information on the output of pattern injection summary vectors for injectors see item 48 of the OPTIONFS keyword.




2 Injector type

WATER Water injector.

GAS Gas injector.

OIL Oil injector.


OPEN Well open for injection.


No other options for FrontSim

• DEFAULT: OPEN

4 Control mode

RATE Controlled by surface flow rate target (Item 5)

RESV Controlled by reservoir volume rate target (Item 6)

BHP Controlled by BHP target (Item 7)

GRUP The well is immediately under group control, to inject its share of a group or field target set with the keyword GCONINJE.

5 Surface flow rate target or upper limit



6 Reservoir fluid volume rate target or upper limit

• UNITS: rm3/day (METRIC) rb/day (FIELD)


7 BHP target or upper limit


SPECIALX FRONTSIM


x SCHEDULE

402 Keywords FrontSim User GuideWCONINJE

It is recommended that this quantity should be set to a value not exceeding the highest pressure in the PVT tables, to ensure the tables are not extrapolated in the well. It is best not to default this quantity, as its value is used in calculating the well potential.


• DEFAULT: 1.0E5 psia or 6895 barsa or the minimum BHP value specified in the PVT data for this well, whichever is lower.

8 1*

9 Injection well VFP table number

(See keyword VFPINJ)

Set to zero if no THP calculations are required

• DEFAULT: 0

Notes1 If a well is set to BHP control the target value has to be set explicitly even if the WELTARG

is previously used to set the default BHP.

2 When control by a surface rate is selected, FrontSim internally converts the specified surface rate to the corresponding total reservoir rate using the pressures and saturations at the beginning of the time step, and controls the well using the total reservoir rate, as if the well were under RESV control.

3 If the pressures and saturations change significantly during the time step, the surface rates also change during the time step. If the discrepancy between the input and calculated surface rates is too large, you need to reduce the time step length: see keyword MAXSTEP. This however increases the CPU time required for the run.

4 Surface rate control is only allowed for water phase in compositional mode.

5 The BHP pressure is constrained to lie below the maximum value of the pressure given in the PVT table used for this well unless this behavior is over ridden using item 44 of FSOPTION.

Examples

Example 1

WCONINJEINJ1 GAS OPEN RATE 500 1* 5000 1000 2 /INJ2 WAT OPEN RESV 1* 1000 4000 /INJ3 WAT OPEN RATE 700 1* 5000 //

FrontSim User Guide KeywordsWCONINJE

403

Example 2WCONINJE supports injection of both water and tracer gas when used together with the IOR scale tracer option module as shown in this example.

WCONINJE INJA WATER 1* RESV 1* 1500 / INJA GAS 1* RESV 1* 600 /

/

404 Keywords FrontSim User GuideWCONINJH

WCONINJH Observed rates for history matching injection wellsThis keyword is used in place of WCONINJE to declare injection wells as special history matching wells, and to enter their observed flow rates (and optionally their measured BHP values).

The equivalent keyword for defining history matching production wells is WCONHIST.

During the simulation these wells are normally be constrained to operate at their observed injection rates, and their calculated BHP values are compared against the measured values.

FrontSim treats history matching wells differently from ordinary injection wells, in the following ways:

• The observed injection rates entered with this keyword can be written to the Summary file, and also the measured BHP values if they are entered here, for comparison with the rates and pressures calculated during the simulation.

• The set of control modes for the wells is restricted to RATE and BHP. The BHP upper limit is automatically set to a large value when the well is first declared a history matching well (the first time it appears in a WCONINJH keyword). This is to reduce the possibility of the well changing to BHP control before its productivity index has been properly matched. (Changing to BHP control at a very high pressure is a sign that the Kh or skin factor is very badly matched.)

You can reset the BHP limit to any desired value with the keyword WELTARG after the first WCONINJH keyword in which the well appears. The well’s BHP limit is not changed by subsequent WCONINJH keywords.

The observed flow rates and pressures can be made to change with time by repeating the WCONINJH keyword at each time step. A history matching well can be converted into a normal well (with the standard set of controls) simply by re-specifying it with the WCONINJE keyword.


The records may be terminated early with a slash (/), the remaining items taking default values. Default values can be specified before the slash by a null repeat count of the form n*, where n is the number of consecutive items to be defaulted.




2 Injector type


GAS Gas injector

OIL Oil injector





SPECIALX FRONTSIM


x SCHEDULE

FrontSim User Guide KeywordsWCONINJH

405

No other options for FrontSim.

• DEFAULT: OPEN

4 Observed injection rate (at surface conditions)


• DEFAULT: 0.0

5 Observed bottom hole pressure (BHP)

Values entered here are only used for reporting purposes, to compare with the calculated BHP. The well does not change to BHP control if the calculated BHP rises above this value. (The actual BHP upper limit is set to a very high value when the well first appears in a WCONINJH keyword, but you can subsequently reset it to any desired value with the WELTARG keyword.)

Default this item if you have no observed BHP value to enter.


• DEFAULT: 0.0

6 Observed tubing head pressure (THP)

Values entered here are only used for reporting purposes, to compare with the calculated THP. Default this item if you have no observed THP value to enter.


• DEFAULT: 0.0


Set this to zero if you do not require the THP to be calculated.

If set > 0, the well’s THP is calculated and reported.

• DEFAULT: Initially zero, subsequently no change from previous value

End the data record with a slash (/). End the set of records with a blank record, containing only a slash.

Example

WCONINJH-- well well open/ inj obs obs-- name type shut rate BHP

WINJ WAT OPEN 2410 /GINJ GAS OPEN 3970 3676 /

/

406 Keywords FrontSim User GuideWCONINJP

WCONINJP Control data for pattern flood injection wellsThis keyword is used to specify a well that injects at reservoir volume rate based on the voidage of associated producers in a pattern. An example of such control would be to specify a well that injects at a rate equal to the sum of one quarter of the voidage from each of the four neighboring producers in a five spot pattern.

This keyword can only be used on one injector well at a time, so it must be specified more than once if there is more than one injection well under this type of control.

The keyword is followed by a data record that specifies the injection well and then, optionally, a number of data records specifying the production wells in the surrounding pattern that each make a contribution to defining the injection well's rate. Each record is terminated with a slash (/), and the set of records must end with an additional blank record containing just a slash.


Record 1This record defines control data for the injection well. It is similar to the WCONINJE keyword except that the injection rate is not specified; this rate is calculated at each time-step from the produced voidage of the surrounding pattern of wells that can be defined in subsequent records of this keyword.

The record may be terminated early with a slash (/), the remaining items taking default values. Default values can be specified before the slash by a null repeat count of the form n*, where n is the number of consecutive items to be defaulted.

1 Name of the pattern flood injection well

2 Injector type


GAS Gas injector


OPEN Well open for injection.


• DEFAULT: OPEN

4 BHP upper limit

Note: It is recommended that this quantity should be set to a value not exceeding the highest pressure in the PVT tables, to ensure the tables are not extrapolated in the well. It is best not to default this quantity, as its value is used in calculating the well potential.


5 Not used


(See keyword VFPINJ)

Set this to zero if no THP calculations are required. THP is computed for reporting purposes only.

• DEFAULT: 0


SPECIALx FRONTSIM


x SCHEDULE

FrontSim User Guide KeywordsWCONINJP

407

7 Not used

8 Injection voidage rate target multiplier

This multiplies the calculated voidage rate target for the pattern flood injector.

• DEFAULT: 1.0


Each subsequent recordThe subsequent records each define a production well and the fraction of its reservoir volume rate that contributes to the overall rate for the injection well specified in record 1.

1 Production well name, well name template or well list.

Well list names should begin with an asterisk (*). Well lists are constructed with the keyword WLIST.

2 The production rate fraction for the well(s) in item 1 of this record

This fraction multiplies the well’s reservoir volume rate (or part thereof, see item 3 below). This product, when added to those from all the other contributing producers, defines the flow rate for the injection well specified in record 1.

• DEFAULT:

The fraction is updated at the beginning of each time step on the basis of the number of injectors assigned to replace the voidage of each producer. A producer’s fractions thus change if one of its associated injectors is shut (or opened), with the current set of open injectors effectively automatically compensating to ensure the producer’s voidage is still replaced

3 Fluid-in-place region number

If this is specified, then the voidage rate contribution from this well is restricted to the sum of the voidage flows from connections to grid cells that fall within this fluid-in-place region. Note that connection voidage rates are calculated at the reference pressures of the appropriate fluid-in-place regions; these pressures may differ from the reference pressure used to calculate the well’s overall voidage rate.

DEFAULT: 0


Notes1 A pattern flood injection well is automatically set as unavailable for higher level group

control.

2 If an injector has previously been defined as a pattern flood injector, it can be switched back to being a normal injector. This switch may be achieved by re-specifying the control mode of the well using the WCONINJE keyword.In this case, injection rates needs to be specified.

3 The control mode of a pattern flood injector is reported in the print file as ‘PFVR’.

408 Keywords FrontSim User GuideWCONINJP

Example 1The water injection well INJW replaces a quarter of the reservoir voidage of each of its four surrounding producers. This is effectively its share of the production voidage in a repeated five spot pattern.

WCONINJPINJW WAT 1* 5000 /PRD1 /PRD2 /PRD3 /PRD4 //

FrontSim User Guide KeywordsWCONPAT

409

WCONPAT Injection Rate OptimizationThis keyword is used to optimize re-allocation of injection rate among a set of injectors to maximize field performance of water floods. The algorithm applied will increase rate in high performance injectors and reduce in low performance injectors. For further information see "Pattern Flood Management" in the "FrontSim Technical Description",


The records may be terminated early with a slash (/). The remaining items assume their default values. Default values can be specified before the slash by a null repeat count of the form n*, where n is the number of consecutive items to be defaulted.


1 List of wells (must be more than 1). Well lists are constructed with the keyword WLIST.

2 Control criteria options:

INJEFF - (Producer Oil-cut)

RECOV - Rate of flooding recoverable oil.

VREP - Pattern voidage replacement.

• DEFAULT: INJEFF

3 Alpha

DEFAULT: 2.0

4 Parameter range: Used to define the range [Betamin, Betamax].

• DEFAULT: 1.0 <0.0, 1.0]

5 Integer value used to control the above range [0,1,.]

0: Betamin = Betaave * (1.0 - range), Betamax = Betaave * (1.0 + range)

1: Betamin =min (Betaave, 0.5* (1.0 - range)), Betamax =max (Betaave, 0.5* (1.0 + range))

• DEFAULT: 0

6 WMIN

• DEFAULT: -0.5 [-1.0, 0.0]

7 WMAX

• DEFAULT: 0.5 [0.0, 1.0]

8 Voidage replacement fraction (option VREP only)

9 Multi-zone water flooding

ON = Multi-zone water flooding is turned on

Note that this will only affect cases where the injectors have lumped completions defined. Rates will be assigned to each lumped completions section separately. Each lumped completion will apply a pressure drop over the valves (ICD) to calculate consistent bottom hole pressures for the wellbore. See OPTIONFS, parameter 61 for more information

OFF = Multi-zone water flooding is turned off

• DEFAULT: OFF



x SCHEDULE

410 Keywords FrontSim User GuideWCONPAT

10 Aquifer cutback fraction - Used to control the cutback of injection into aquifer

• DEFAULT: -0.25 [-1.0, 0.0]

11 Aquifer Loss: integer value [0,1]

0 = reallocate the cutback due to aquifer loss (item 10) among other injectors

1 = reduce overall injection by the calculated cutback of rate due to aquifer loss (item 10)

• DEFAULT: 0

12 Injection Capacity.: Target and limit for wells given by item #1. If defaulted - (group) target from previous timestep is used.

Note When using WCONPAT FrontSim will generate a separate pfm_sched file including updated (optimized) well rates for all wells (using WCONPROD/WCONINJE and DATES keywords).

Note When PFM is in operation wells do not honor group controls targets or limits. Wells will honor their bottom-hole pressure targets or limits and their rate limits (both RESV and RATE).Injectors under PFM will honor their injection capacity as specified by item 12. For more details see the "Pattern Flood Management" in "FrontSim Technical Description"A dataset illustrating the use of PFM is available with the installation

Note It is recommended, wherever possible, to start Pattern Flood Management (PFM) with none or few well and group constraints/limits and simple well schedules. Constraints should be gradually introduced once the performance of the pattern flood management with minimum constraints is acceptable. The rules governing the behavior of WCONPAT when used with other well management routines is described in "Pattern Flood Management" in "FrontSim Technical Description". Knowledge of these rules is essential to correct application. Complex scheduling and application of intricate well management routines together with PFM can be challenging and you are advised to contact the help desk before proceeding.Please refer to the FrontSim installation for sample data sets showing the use of PFM.

Example

WCONPAT-- WELLS CITERIA ALPHA RANGE TYPE MIN. MAX Res Voidage Aquifer Aquifer Spacing-- WT WT erved Fraction Cutback Realloc Injection Capacity*LIST1 RECOV 1.0 1.0 0 -0.5 0.5 1* 1* -0.3 1 700 //

FrontSim User Guide KeywordsWCONPEND

411

WCONPEND Switch Off Injection Rate OptimizationThis keyword is used to switch off injection rate optimization previously specified with WCONPAT. The wells previously under optimization will now run on single well control with the target rate from the last optimization. For further information see "Pattern Flood Management" in the "FrontSim Technical Description",




1 List of wells (must be more than 1). Well lists are constructed with the keyword WLIST.

2 Open/shut flag for well



• DEFAULT: Open

Notes1 If the optimization is turned off - it can later be switched on again by re-specifying the

WCONPAT keyword.

Example


SPECIALx FRONTSIM


x SCHEDULE

WCONPEND*LIST1 OPEN //

412 Keywords FrontSim User GuideWCONPROD

WCONPROD Control data for production wellsThe keyword is followed by any number of records, each containing the following items of data, and each terminated with a slash (/).






OPEN Well open for production


3 Control mode

ORAT Controlled by oil rate target (Item 4)

WRAT Controlled by water rate target (Item 5)

GRAT Controlled by gas rate target (Item 6)

LRAT Controlled by liquid rate target (Item 7)

RESV Controlled by reservoir fluid volume rate target (Item 8)

BHP Controlled by BHP target (Item 9)

GRUP The well is immediately under group control, to produce its share of a group or field target rate set with keyword GCONPROD.

• DEFAULT: ' ' (Undefined)

4 Oil rate target or upper limit



5 Water rate target or upper limit



6 Gas rate target or upper limit



7 Liquid rate target or upper limit




SPECIALx FRONTSIM


x SCHEDULE

FrontSim User Guide KeywordsWCONPROD

413

8 Reservoir fluid volume rate target or upper limit

• UNITS: rm3/day (METRIC), rb/day (FIELD


9 BHP target or lower limit


• DEFAULT: 14.7 psia, or 1.0 barsa

10 1*

11 Production well VFP table number


Set to zero if no THP calculations is required

• DEFAULT: 0

12 Artificial lift quantity, for use in THP calculations


Set to zero if no THP calculations is required

• DEFAULT: 0.0

Notes1 If the a well is set to BHP control the target value has to be set explicitly even if the

WELTARG is previously used to set the default BHP.

2 When control by a surface rate is selected, FrontSim internally converts the specified surface rate to the corresponding total reservoir rate using the pressures and saturations at the beginning of the time step, and controls the well using the total reservoir rate, as if the well were under RESV control.

3 If the pressures and saturations change significantly during the time step, the surface rates also change during the time step. If the discrepancy between the input and calculated surface rates is too large, you need to reduce the time step length, see keyword MAXSTEP. This however increases the CPU required for the run.

4 Surface rate control is not allowed in compositional mode.

5 Wells may not honor their phase (oil, water, gas) rate targets exactly. This is a limitation of the IMPES nature transport solution procedure. Users may attempt to resolve this issue by tuning the size of time steps.

ExampleWCONPRODPROD3 OPEN LRAT 2* 5000 1000 1* 2000 100 1 0.0 /PROD4 OPEN ORAT 1000 2000 3* 2000 /PROD1 OPEN RESV 4* 1000 2000 //

414 Keywords FrontSim User GuideWECON

WECON Economic limit data for production wellsThe keyword is followed by any number of records, each containing the following items of data, and each terminated with a slash (/).

The records may be terminated at any item after Item 1. The remaining items assume their default values. Default values can be specified before the slash by null repeat counts of the form n*, where n is the number of consecutive items to be defaulted.





If the oil production rate falls below the specified minimum, the well is shut.

A zero or negative value switches off this limit.


• DEFAULT: 0.0


If the gas production rate falls below the specified minimum, the well is shut.


• DEFAULT: 0.0

4 Maximum water cut

The water cut is the ratio of water to total liquid (oil + water) surface volume production rates.



5 Maximum gas-oil ratio



6 Maximum water-gas ratio



7 Workover procedure on exceeding water cut, GOR, WGR or GLR limit

NONE No action to be taken

CON Shut worst-offending connection

+CON Shut worst-offending connection and all those below it.

WELL Shut or stop the well.

• DEFAULT: NONE


x

SPECIAL

FRONTSIMRUNSPECGRIDEDITPROPSREGIONSSOLUTIONSUMMARY

x SCHEDULE

FrontSim User Guide KeywordsWECON

415

ExampleWECONPROD1 500 1* 0.8 /PROD2 100 5* Y /PROD3 100 //

416 Keywords FrontSim User GuideWECONINJ

WECONINJ Economic limit data for injection wellsThe keyword is followed by any number of records, each containing the following items of data, and each terminated with a slash (/).

The records may be terminated at any item after Item 1. The remaining items assume their default values. Default values can be specified before the slash by null repeat counts of the form n*, where n is the number of consecutive items to be defaulted.




2 Minimum economic injection rate.

If the injection rate falls below the specified minimum, the well is shut or stopped (see item 9 in keyword WELSPECS). This rate applies to the phase specified in Item 2 of the keyword WCONINJ or WCONINJE.

If Item 3 below is POTN, the minimum rate limit is applied to the well’s oil/water/gas injection potential instead of its actual rate.

A zero or negative value switches off this limit.

• UNITS: As appropriate for Item 2 of WCONINJ/WCONINJE

• DEFAULT: 0.0



Example



x SCHEDULE

WECONINJINJ1 500 RATE /INJ2 800 POTN //

FrontSim User Guide KeywordsWEFAC

417

WEFAC Sets well efficiency factors (for downtime)The keyword is followed by any number of records, each containing the following items of data, and each terminated with a slash (/).





2 Efficiency factor for the well(s)

This is the fractional time for which the well is operational. For example, if the well is ‘down’ for 10 percent of the time, its efficiency factor will be 0.9.

The efficiency factor must be greater than zero.

• DEFAULT: 1.0

Ignored by FrontSim 3 1*



The efficiency factors for wells not specified with this keyword are defaulted to 1.0.

Treatment of downtimeEach well is solved at its full flowing conditions, and the well rates and pressures given in the well reports describe the state of the flowing well. However, the flow rates are multiplied by the well’s efficiency factor when:

• The well rates are summed to give the group flow rates,

• The well rates are multiplied by the time step and added to the cumulative flows,

• The connection flows are applied as source/sink terms in the reservoir material balance equations.

This essentially treats the wells as going down individually for random short intervals within each time step, rather than all going down simultaneously.The group and field flows represent the average flow rates over the period. For example, if the efficiency factors are all 0.5, the well’s individual flow rates sum to twice the group rate, but only half of them are flowing at any given instant on average.

If a group flow target is applied (for example with GCONPROD), this is interpreted as the target average flow rate of the group with the wells flowing intermittently according to their efficiency factors. The effect of the wells’ downtime is to make the wells flow proportionately more while they are operating. For example, consider a group with a target oil rate of 10,000 stb/day to be divided equally between its 10 wells. If all wells had zero downtime, each would produce 1,000 stb/day. However, if they all have an efficiency factor of 0.8, each well must produce 1,250 stb/day while it is flowing to make up the group’s target rate, provided that the wells’ flowing conditions at this rate do not violate any of their operating limits.


SPECIALRUNSPECGRIDEDITPROPSREGIONSSOLUTIONSUMMARY

x SCHEDULE

418 Keywords FrontSim User GuideWEFAC

ExampleWEFAC'P*' 0.9 /PROD2 0.8 //

FrontSim User Guide KeywordsWELLDIMS

419

WELLDIMS Well dimension dataThe data consists of up to four items, describing the dimensions of the well data to be used in the run. The data must be terminated by a slash(/).

This keyword is ignored by FrontSim, but can be inserted in the file for compatibility. The numbers of wells, etc., are dimensioned dynamically according to the actual data specified in the other well keywords.

1 NWMAXZ: The maximum number of wells in the model.

• DEFAULT: 0

2 NCWMAX: The maximum number of connections per well (that is, the maximum number of grid blocks connected to any one well).

• DEFAULT: 0

3 NGMAXZ: The maximum number of groups in the model.

• DEFAULT: 0

4 NWGMAX: The maximum number of wells in any one group.

• DEFAULT: 0

Example




WELLDIMS20 3 2 10 /

420 Keywords FrontSim User GuideWELLSTRE

WELLSTRE Set composition of injection gas streamWhen, in a compositional run, oil or gas is injected using a stream, this keyword may be used to specify the composition of the injected stream.

The keyword is followed by any number of records, each containing the items of data described below, and each terminated with a slash (/).

The records can be terminated early with a slash, the remaining items taking default values. Defaults can also be specified by a null repeat count of the form n*, where n is the number of consecutive items to be defaulted.

The set of records is ended by a blank record, containing only a slash.

1 The name of the well stream.

The maximum number of wellstreams allowed is governed by item 6 of keyword WELLDIMS.

2 , the mole fraction of the first component.

3 , the mole fraction of the second component.

.

.

.

, the mole fraction of the th component.

mole fractions should be specified, where is the number of components in the run. The values will be checked using the condition that the sum of the mole fractions must be 1.0.

Once the well stream is defined, it may be used in the WINJGAS keyword, for example, to specify an injected composition, or used to define a make-up gas.

Example


SPECIALx FRONTSIM


x SCHEDULE

WELLSTRE'MixB' 0.5 0.3 0.1 0.05 0.05 //

x1

x2

Nc 1+ xNcNc

Nc Nc

FrontSim User Guide KeywordsWELOPEN

421

WELOPEN Shuts or reopens wells or well connectionsThis keyword can be used to shut or reopen wells or well connections, without having to specify the rest of the well control data or connection data. To shut or reopen a well, leave items 3 - 7 defaulted. To shut or reopen individual well connections, enter their I,J,K location in items 3 - 5.


The records may be terminated after item 1 or item 2, in which case the remaining items assume their default values.




2 Open/shut flag for the well or connections

OPEN Well or connections open to flow.

SHUT Well or connections completely isolated from formation.

• DEFAULT: OPEN





5 K - location of connecting grid block(s)

• DEFAULT: NegativeIgnored by FrontSim 6 1*Ignored by FrontSim 7 1*

If items 3 - 5 are all defaulted, the Open/Shut/Stop command applies to the well, leaving the connections unchanged. An attempt to open a well with no connections open will result in an error condition.

If any of items 3 - 5 are set zero or positive, the command applies to the eligible connections of the well, leaving the status of the well itself unchanged. The eligible connections are those with I,J,K locations matching the specified location indices in items 3 - 5. A zero or negative value for a location index (I, J or K) matches any value of that location index.

To open a well and one or more of its connections requires two records, one to operate on the well and the other to operate on the connections.


End the set of records with a blank record containing just a slash.


SPECIALx FRONTSIM


x SCHEDULE

422 Keywords FrontSim User GuideWELOPEN

Example

WELOPEN'*' / opens all shut or stopped wells in the fieldPROD3 SHUT / shuts well PROD3, if it is open'*' OPEN 0 0 3 / opens all well connections in layer 3PROD4 OPEN 0 0 0 / opens all connections of well PROD4PROD5 SHUT 0 0 4 / shuts connection(s) to layer 4 in well PROD5/

FrontSim User Guide KeywordsWELPI

423

WELPI Sets well productivity/injectivity index valuesThis keyword can be used to set the productivity/injectivity index (P.I.) value of one or more wells to a specified value. The well connection properties must be defined in the usual manner, with keyword COMPDAT, but the connection transmissibility factors are adjusted proportionately so that the calculated P.I. of the well equals the specified value.

The adjustment of the connection factors is performed at the time the WELPI keyword is entered, using the current grid block solution. If the fluid mobilities in the grid blocks subsequently change, the well’s actual P.I. also changes.





2 Steady-state productivity/injectivity index value of the well(s)

• UNITS: sm3/day-bar (METRIC), stb/day-psi (FIELD). or Mscf/day-psi (FIELD)

End the data record with a slash (/). End the set of records with a blank record, containing just a slash.

Example


SPECIALx FRONTSIM


x SCHEDULE

WELPIPROD1 10.2 /PROD2 14.3 //

424 Keywords FrontSim User GuideWELSPECL

WELSPECL General specification data for wells in local gridsWELSPECL must be used in place of WELSPECS to set the general specification data for wells in local refined grids. The keyword data is similar to that for WELSPECS, except there is an additional item at position 3 that gives the name of the local grid refinement in which the well is located. The connection data for these wells must be specified using the keyword COMPDATL instead of COMPDAT.

Example



x SCHEDULE

WELSPECLPROD1 G1 LGR1 6 8 6000 LIQ /INJE1 G1 LGR2 3 2 6000 WATER //

FrontSim User Guide KeywordsWELSPECS

425

WELSPECS General specification data for wellsThe keyword introduces a new well, defining its name, the position of the wellhead, its bottom hole reference depth and other specification data.


The records may be terminated early with a slash (/); the remaining items assume their default values. Default values can also be specified before the slash by a null repeat count of the form n*, where n is the number of consecutive items to be defaulted.


1 Well name: (Up to 8 characters)

2 Name of the group to which the well belongs: (Up to 8 characters)

If this record is defaulted or blank, the group name is set to FIELD.

3 I - location of well head or heel

4 J - location of well head or heel

For horizontal wells, items 3 and 4 define the location of the heel of the well, and thus determine the way that FrontSim orders the connections (see Item 13 in the COMPDAT keyword). If all connections are vertical, items 3 and 4 are used for reporting purposes only; the well can still connect with grid blocks having different I- and J- locations.

5 Reference depth for bottom hole pressure

This should be situated in the vicinity of the perforations. A recommended location is the top-most perforation of the well.

If this quantity is defaulted or given a negative value, the reference depth is set equal to the center depth of the grid block containing the top-most connection in the well.

• UNITS: m (METRIC), ft (FIELD)Required but not used by FrontSim

6 Preferred phase for the well

OIL The well is primarily an oil well

WATER The well is primarily a water well

GAS The well is primarily a gas well

LIQ May be used to output the oil + water phase P.I.Required but not used by FrontSim

7 1*


8 1*


9 1*

10 Crossflow ability flag

YES Crossflow allowed in the well

NO Crossflow not allowed; the connections act as one-way valves, preventing flow if there is a reverse drawdown

• DEFAULT: YES


11 1*


SPECIALx FRONTSIM


x SCHEDULE

426 Keywords FrontSim User GuideWELSPECS


12 1*


13 1*

FrontSim only 14 Optional X coordinate of well (I index is ignored).FrontSim only 15 Optional Y coordinate of well. (J index is ignored)


Example

WELSPECSPROD1 G1 6 8 6000 LIQ /INJE1 G1 3 2 6000 WATER //

FrontSim User Guide KeywordsWELSTRDN

427

WELSTRDN Stream density for wellIncreases/decreases the number of streamlines starting in a named well.

The keyword is followed by any number of records, described below, each record terminated by a slash (/). The set of records must end with a blank record, containing only a slash (/).

1 Well name

2 Multiplier for the number of streamlines starting in the well.

• DEFAULT: 1.0

Example



x SCHEDULE

WELSTRDNP1 1.25 /P2 1.5 //

428 Keywords FrontSim User GuideWELTARG

WELTARG Resets a well operating target or limitThis keyword can be used to reset a target or limit value for a well, without having to re-specify all the other quantities required by the control keywords WCONPROD or WCONINJE. These other quantities are left unchanged, including the open/shut status of the well. The well control data must initially have been fully specified using WCONPROD or WCONINJE.

If the well has been declared a history matching well (see keyword WCONHIST) the WELTARG keyword may be used to modify its BHP limit. The other quantities should not be modified with this keyword.





2 Definition of the control or constraint quantity to be changed

ORAT: Oil rate

WRAT: Water rate

GRAT: Gas rate

LRAT: Liquid rate

RESV: Reservoir fluid volume rate


3 New value of this quantity

The units depend upon the quantity chosen. The appropriate units are listed in the specification for keywords WCONPROD and WCONINJE.



Note If a well name root is used for the well name, such as 'P*', the default BHP limit for all wells matching the well name root will be changed, whether or not they have been defined at the point in the dataset where the WELTARG keyword occurs (see Example 1). This will only modify the default BHP limit and not set the well to be controlled by BHP. This is not valid for other control types and constraint quantities, like ORAT, etc.

Note In all cases other than that described above, the WELTARG keyword must be preceded by one of WCONPROD or WCONINJE or WCONHIST.


SPECIALx FRONTSIM


x SCHEDULE

FrontSim User Guide KeywordsWELTARG

429

Examples

Example 1

Example 2

-- Setting the default BHP limit to 3000 psi for all wells (P*)WELTARGP* BHP 3000 //WELSPECSP1 .. /P2 .. //WCONHISTP1 .. //

WELTARGPROD1 ORAT 1500 /PROD2 BHP 3000 //

430 Keywords FrontSim User GuideWFRICTN

WFRICTN Designates a well as a friction wellThis keyword is used to designate a well to be a friction well, for which the frictional pressure losses between the connections and the well’s bottom hole reference point are calculated and included in the connection head terms. This facility is primarily intended for use with horizontal wells, in which frictional pressure losses may be significant over the horizontal section of the wellbore and in the branches.

This keyword can only be used on one well at a time, so the keyword must be specified more than once if there is more than one friction well. If the keyword is repeated for a particular well (for example to add a new branch or new connections), the data for the entire well must be supplied each time the keyword is used.

The keyword is followed by a number of data records to describe the properties and geometry of the (possibly multi-branched) well. Each record is terminated with a slash (/), and the set of records must end with an additional blank record containing just a slash.


Record 1The first record identifies the well and sets the tubing diameter, roughness and flow scaling factor, which are used in the friction pressure loss calculation.

1 Name of the well

2 Tubing internal diameter

This quantity is used for calculating the frictional pressure drop between the connections and the well’s bottom hole reference point. It need not be the same as the wellbore diameter set in COMPDAT item 9, which is used to calculate the connection transmissibility factors.

Different internal diameters may be set for individual connections, with Item 8 in subsequent records.


3 The effective absolute roughness of the tubing

This quantity is used to calculate the Fanning friction factor.


4 Flow scaling factor (dimensionless)

The volumetric flow rate in the wellbore is multiplied by the scaling factor when the friction pressure drop is calculated. This quantity is useful if the well is being simulated in a half or quarter grid, taking advantage of symmetry. In this case, the well’s flow rate is only a half or quarter of the true flow rate. The scaling factor can then be used to multiply the connection flow rates by 2 or 4, so that the true flow rate is used in the friction calculation.

• DEFAULT: 1.0



x SPECIALx FRONTSIM


x SCHEDULE

FrontSim User Guide KeywordsWFRICTN

431

Each subsequent recordThe subsequent records set the start and end of each connection’s perforations in terms of distance along the tubing from the well’s bottom hole reference point. These distances are required by the frictional pressure drop calculation, which treats each connection’s flow as entering the tubing half way between the start and end of the perforations in the grid block. The bottom hole reference point should be downstream for a producer (upstream for an injector) of all the perforations. A suitable position is at the start of the perforations (the end nearest the wellhead). The order in which these records are entered are used to determine the structure of the well. For standard horizontal wells, the connections should be entered in order of increasing distance from the bottom hole reference point, that is from the heel out to the toe.

The connections may either be specified individually, or in one or more “ranges”. A range is a contiguous row or column of grid blocks that are fully penetrated by the well. The well is assumed to penetrate a range perpendicularly through the center of each grid block in the specified direction. The distance along the tubing to the start and end of each connection in the range is determined by summing the DX, DY or DZ thicknesses of the grid blocks in the range. All connections in the well must have their tubing distances set, either individually or within a range, working from the connection nearest the well’s bottom hole reference point out to the furthest connection of the well.

For a standard horizontal well, each connection should be referenced by this keyword just once, either individually or as part of a range. All connections must have been defined initially in keyword COMPDAT. Note that there must therefore be a connection defined at each branch point.

1 I - location of the individual connection, or the connection at the start of the range (nearest the well’s bottom hole reference point)

2 J - location of the individual connection, or the connection at the start of the range (nearest the well’s bottom hole reference point)

3 K - location of the individual connection, or the connection at the start of the range (nearest the well’s bottom hole reference point)

4 Distance down the tubing from the well’s bottom hole reference point to the start of the perforations in this grid block

This item must not be negative.


5 Distance down the tubing from the well’s bottom hole reference point to the end of the perforations in this grid block

This item must be greater than item 4.



End the set of data records with a slash.

432 Keywords FrontSim User GuideWFRICTN

ExampleA well called HORIZ with 6 connections. This example sets the tubing lengths manually for each connection of the well 'HORIZ'

WFRICTN-- Name Diam Roughness Scalefac

HORIZ 0.25 1.0E-3 1.0 /-- I J K Tlen1 Tlen2

3 5 6 0.0 100.0 /4 5 6 100.0 200.0 /5 5 6 200.0 400.0 /6 5 6 400.0 600.0 /7 5 6 600.0 700.0 /8 5 6 700.0 800.0 /

/

FrontSim User Guide KeywordsWINJGAS

433

WINJGAS Specify the nature of injection gas This keyword specifies the nature of the gas to be injected by a gas injection well. This should be used if WCONINJE is used to specify control data for gas injection wells in compositional models.

The keyword is followed by any number of records, each containing the items of data described below, and each terminated with a slash (/).

The records can be terminated early with a slash, the remaining items taking default values. Defaults can also be specified by a null repeat count of the form n*, where n is the number of consecutive items to be defaulted.

The set of records is ended by a blank record, containing only a slash.



2 A character string specifying the nature of the fluid to be injected.Required for FrontSim STREAM The molar composition of the injected fluid has been defined using the

WELLSTRE keyword. The name of the stream must be entered in item 3.

3 A character string is required if the composition of the injection fluid was specified using STREAM in item 2.

In these cases this argument is a character string specifying the name of the well stream, mixture, group or well that defines or supplies the injection stream.

Example


SPECIALx FRONTSIM


x SCHEDULE

WINJGAS'I*' GV Field /'I1' STREAM Istream //

434 Keywords FrontSim User GuideWLIST

WLIST Sets up lists of well names The keyword WLIST may be used to construct and maintain well lists, which are lists of well names. Well lists whose names begin with an asterisk (*) may be entered wherever a well name root can be entered in the SCHEDULE section well keywords, as an alternative method of specifying several wells at once.

Each list should have a unique name, consisting of up to eight characters. The first character must be an asterisk and the second character must be a letter. Each list may contain any number of well names. Up to 50 well names may be added to a list in a single data record. Lists containing more than 50 well names may be constructed by appending well names to the list in subsequent data records. Wells may be added to, deleted from or moved between lists at any time in the simulation. In ECLIPSE 100 each well can be a member of only one list at a time. In ECLIPSE 300 a well may belong to more than one list at a time, up to a maximum as set in item 11 of WELLDIMS.

1 The well list name.

This should consist of up to 8 characters, enclosed in quotes. The first character of the list name must be an asterisk and the second character must be a letter.

2 The operation.

This must be:

NEW Starts a fresh list having the specified name. If a list with that name already exists, all well names are first removed from it. The following well names are then placed on the list.

Note These wells must not currently be members of any other list.

ADD: Appends the following well names to the list. (Note that these wells must not currently be members of any other list.)

MOV: Moves the following wells from whatever list they are currently a member of to the list named in item 1, appending them to the end of this list.

DEL: Removes the following well names from the list named in item 1.

3 A list of well names.

The wells must previously have been declared with the WELSPECS keyword.

Well name roots (enclosed in quotes and ending with an asterisk) may also be used here. When a well name root is encountered, all currently declared wells whose names match the name root will be processed. The wells are added to the list in the order in which they were first declared in the simulation.



SPECIALx FRONTSIM


x SCHEDULE

FrontSim User Guide KeywordsWLIST

435

ExampleThis example first creates a fresh well list *LIST1 containing 8 wells:

WLIST-- List Oper Well-- Name -atn Names...............'*LIST1' NEW PR5 WEL63 VV6 TS53 PR22 VV12 TS7 TS19 //WCONPAT'*LIST1' INJEFF 1.5 /'*LIST2' INJEFF 1* 1* 1* -0.25 //

436 Keywords FrontSim User GuideWPAVE

WPAVE Well block average pressure controlsThis keyword controls the calculation of well block average pressures. These averages represent the average pressure of the grid blocks containing connections to a given well, weighted according to either the connection transmissibility factors or the grid block pore volumes. WPAVE controls the averaging method for all wells in the simulation.

The average pressures can be written to the Summary file using the SUMMARY section keyword WBP.

The averages are used for reporting purposes only, and will not affect any other results.

The keyword should be followed by a line containing the following items of data, terminated by a slash (/):


1 F1, the weighting factor between the inner block and the outer ring of neighboring blocks, in the connection factor weighted average.


2 F2, the weighting factor between the connection factor weighted average and the pore volume weighted average. This always uses the default value.

• DEFAULT: 0.0

3 Depth correction flag

This flag controls how the grid block pressures are corrected to the well’s bottom hole reference depth (see item 5 in keyword WELSPECS), or to an alternative reference depth if specified in keyword WPAVEDEP, by applying a hydrostatic head between each grid block center and the well’s reference depth.

WELL: The hydrostatic head is calculated using the density of the fluid in the wellbore at the well connections.

RES: The hydrostatic head is calculated using a representative density for the fluid in the reservoir. This density is calculated by averaging over fluid density for all the grid blocks associated with the well’s connections. The average over phases is weighted by the phase saturation, and the average over grid blocks is weighted by pore volume. Whether the averaging is performed over all grid blocks with declared connections to the well or only those with currently open connections is determined by item 4.

NONE: Grid block pressures are not depth corrected.

• DEFAULT: WELL

Note The wellbore fluid density is set to zero whenever the well is shut. Thus if WELL is selected there is a discontinuity in the reported pressure average when the well’s status changes between shut and open/stopped.

4 Well connection flag

This flag controls whether the grid blocks associated with all the well’s declared connections contribute to the average pressure, or just those associated with the currently open connections.

OPEN: Only grid blocks associated with currently open connections are included in the averaging calculation.

ALL: Grid blocks associated with all currently defined connections (whether open or closed) are included in the averaging calculation.

• DEFAULT: OPEN


SPECIALx FRONTSIM


x SCHEDULE

FrontSim User Guide KeywordsWPAVE

437

Note If OPEN is selected there is a discontinuity in the reported pressure average whenever new connections are opened or existing ones are closed. This may be avoided by selecting ALL and defining all the well’s connections at the start of the run (whether initially open or closed).

If this keyword is not present, all items assume their default values, giving a connection factor weighted average, evenly weighted between the inner blocks and the outer ring of neighbors. The depth correction uses the wellbore density and only grid blocks associated with currently open well connections are included in the average.

Examples

Example 1To give a connection factor weighted average, with increased weighting to the outer blocks:

Example 2To give a purely pore volume weighted average over all the blocks containing open or closed well connections and their neighbors:

Example 3To give a connection factor weighted average, where the pressure for each connection is the pore volume weighted average of pressures in the connection block and its outer ring of neighbors. The grid block pressures are not depth corrected:

Pore volume weighted averageThis is simply the average depth-corrected pressure in the selected set of grid blocks , weighted by their pore volumes

[EQ 6.43]

The set of grid blocks j is selected from the blocks containing (open or declared, depending on item 4) connections of the well (i).

WPAVE0.2 1.0 /

WPAVE1* 0.0 1* ALL /

WPAVE-1.0 1.0 NONE /

Pj j

Vj

Pw pv,

VjPjj

∑

Vjj

∑-----------------=

438 Keywords FrontSim User GuideWPAVEDEP

WPAVEDEP Reference depth for well block average pressure calculationThis keyword may be used to modify the reference depth for the calculation of well block average pressures (see keyword WPAVE) for output to the Summary file. By default, the grid block pressures are corrected to the well’s bottom hole reference depth (see item 5 in keyword WELSPECS) by applying a hydrostatic head. The WPAVEDEP keyword enables the use of an alternative reference depth, which is used solely for this calculation.

The depth correction is calculated using either the fluid density in the well bore at the depth of the well connections, or the fluid density in the grid blocks associated with the well’s connections, as requested in item 3 of keyword WPAVE.



1 Well name, well name template, well list or well list template

A template enclosed in quotes can be used to refer to multiple wells or well lists. See "Well Modeling Facilities" in the "FrontSim Technical Description" for further details. Well list names should be enclosed in quotes and begin with an asterisk (*). Well lists are constructed with the keyword WLIST.

2 The reference depth for the calculation of well block average pressures.

• UNITS: metres (METRIC), feet (FIELD)

• DEFAULT: Use the well’s bottom hole reference depth

End data record with a slash (/). End the set of records with a blank record, containing just a slash (/).

Example


SPECIALx FRONTSIM


x SCHEDULE

WPAVEDEP'PROD1*' 3640 //

FrontSim User Guide KeywordsWPIMULT

439

WPIMULT Multiplies well connection factors by a given valueThis keyword can be used to multiply the connection transmissibility factors of selected well connections by a specified value. To multiply the transmissibility factors of all the connections in a well, leave items 3 - 5 defaulted. To multiply the transmissibility factors of a subset of connections in a well, you can identify the subset by their I,J,K location (items 3 - 5).

The WPIMULT keyword is followed by any number of records, each containing the following items of data, and each terminated with a slash (/).




2 Multiplier to act on the well’s connection transmissibility factors and Kh values

The value must be greater than 1.0E-10

• DEFAULT: 1.0


• DEFAULT: Negative (allows any I-location)


• DEFAULT: Negative (allows any J-location)

5 K - location of connecting grid block(s)

• DEFAULT: Negative (allows any K-location)

If any of items 3 - 5 are set positive, the multiplying factor will apply only to a subset of the connections in the well. The connections in the subset are those with I,J,K locations matching the specified location indices in items 3 - 5.

Notes1 When WPIMULT is read, the connection factors of the chosen set of connections are

immediately multiplied by the specified factor. If the COMPDAT keyword is subsequently used to reset any of their connection data, this will cause the connection factors to be reset. If the multiplier is still required, WPIMULT must be entered again after COMPDAT.

2 If WPIMULT is used more than once on the same set of well connections, without resetting the connection factors with an intermediate COMPDAT keyword, its effect will be cumulative: the multiplying factor will be applied each time the keyword is entered.


SPECIALx FRONTSIM


x SCHEDULE

440 Keywords FrontSim User GuideWPIMULT

Example

WPIMULTPROD1 1.3 / (all connections in the well PROD1)PROD2 0.82 1* 1* 5 / (all connections of well PROD2 in layer 5)/

FrontSim User Guide KeywordsWRFTPLT

441

WRFTPLT Requests output of well RFT, PLT and segment data to the RFT file The keyword initiates output of well data to the RFT file. This file contains data for one or more wells describing fluid conditions in the wellbore or the connecting grid blocks at selected times in the run. There are three categories of data that may be written to this file:

• RFT data - the depth, pressure and water and gas saturations in each grid block containing a connection to the well.

• PLT data - the depth, pressure, and oil, water and gas flows at each connection in the well, and also the tubing flows at each connection (that is the total upstream flow rates at both surface conditions and local wellbore conditions). The connection transmissibility factor and Kh value are reported for each connection.

Unformatted RFT files can be converted to formatted files by using the CONVERT utility. A detailed list of the contents of the file can be found in the "ECLIPSE File Formats Reference Manual".

The WRFTPLT keyword is followed by any number of records, each containing the following items of data, and each terminated with a slash (/). The set of records must end with a blank record, containing only a slash (/).



2 Output RFT data?

YES: Output the current RFT data for the well(s) at this time, describing conditions in the grid blocks containing well connections.

REPT: Output the current RFT data for the well(s) at this time and at all subsequent report times.

FOPN: Output the current RFT data for the well(s) at this time if they are open. If any of the wells named in Item 1 are not yet open, output their RFT data subsequently when they are first opened.

NO: Do not output RFT data for the well(s).

• DEFAULT: NO

3 Output PLT data?

YES: Output the current PLT data for the well(s) at this time, describing the flows through the well connections.

REPT: Output the current PLT data for the well(s) at this time and at all subsequent report times, while they are open or stopped.

NO: Do not output PLT data for the well(s).

• DEFAULT: NO

End the data record with a slash (/). End the set of records with a blank record, containing only a slash (/).

The automatic output of data at subsequent times can be cancelled by re-entering WRFTPLT with the NO option selected.


SPECIALx FRONTSIM


x SCHEDULE

442 Keywords FrontSim User GuideWRFTPLT

Examples

Example 1Request RFT data output for any currently declared well now (if open) or when it is subsequently first opened.

Example 2Request current PLT data output for specified wells, now and at subsequent report times.

WRFTPLT--Well RFT PLT Segment--Name Data Data

'*' FOPN //

WRFTPLT--Well RFT PLT Segment--Name Data Data Data

PROD1 NO REPT /'A*' NO REPT //

FrontSim User Guide KeywordsWSOLVENT

443

WSOLVENT Sets solvent fraction for gas injection wells This keyword specifies the fraction of solvent in the injected gas stream, with simultaneous injection of water and gas in the surface units. The keyword is used when the IOR scale option logic in history mode is active, with TPVT set in the PROPS section.

WSOLVENT is defaulted to 0.0 when the injected gas is considered to be lean gas (T4, or T7). In such cases WSOLVENT does not have to appear after WCONINJE. A WSOLVENT value of 1.0 indicates that the injected gas is 100% solvent (T1), when WSOLVENT must be specified as shown in the example below.

Current implementation specifies the fraction of solvent to be either 0.0 or 1.0.





2 The fraction of solvent in the injection stream for the well

This must be set to either 0.0 or 1.0.

Example

Notes1 The WSOLVENT keyword is only used with the IOR tracer logic, and only with two-phase

models.

2 The FRACTION parameter implicitly specifies the injection tracer type.


x SPECIALx FRONTSIM


x SCHEDULE

WCONINJEINJ1 WAT OPEN RATE 1* 5000 /INJ1 GAS OPEN RATE 1* 1000 /

/WSOLVENT

INJ1 1.0 //

444 Keywords FrontSim User GuideWTEMP

WTEMP Sets the temperature of a water injection wellThis keyword is used to specify the value of the temperature of the injected water.





2 The injected water temperature.

• UNITS: °C (METRIC), °F (FIELD)


End the set of records with a blank record, containing just a slash (/).

See also keywords HEATCAP, RTEMP.

Example



x SCHEDULE

WTEMPINJ1 40.0 /INJ2 45.0 //

FrontSim User Guide KeywordsWTEST

445

WTEST Instructions for periodic testing of closed wellsThe keyword is followed by any number of records, each containing the following items of data, and each terminated with a slash (/). The set of records must end with a blank record, containing only a slash (/).



2 Testing interval

This must be greater than zero.

• UNITS: days (METRIC), days (FIELD)

The well is tested at the beginning of the first time step that starts after the specified interval has elapsed since it was closed. Subsequent tests are performed at each time step that starts after the specified interval has elapsed since the previous test.

If the testing interval is very small (for example, 1 day), the well is tested at the beginning of each time step (unless of course the time steps are smaller than this).

3 Closure reason(s) valid for testing

A string of up to 5 characters.

If the string contains a P:

The well is tested if it has been closed for any physical reason (for example failure to operate at its BHP or THP limit). It is opened if the test shows that it can operate again.

If the string contains a G:

The well is opened if it has been closed due to a GROUP or FIELD limit set in keyword GECON or the GCON---- family. The well is opened unconditionally, since it cannot be tested in isolation. If it causes a group or field limit to be broken, the remedial action is performed at the end of the time step in the usual manner. If the well has no open connections, all connections closed by automatic workovers are reopened.

• DEFAULT: ' ' (an empty string, which turns off the testing process for the well)

4 Number of times the well can be tested

An integer between 0 and 32767

After the well has been tested this number of times (regardless of whether any tests are successful), it is not tested any more unless this item is reset in a subsequent use of the WTEST keyword.

A value of 0 allows the well to be tested an unlimited number of times.

• DEFAULT: 0Required - but not used by FrontSim

5 1*


End the set of records with a blank record containing just a slash.


SPECIALx FRONTSIM


x SCHEDULE

446 Keywords FrontSim User GuideWTEST

Example

WTEST'PROD*' 100 PG /W1 150 P 10 /

/

FrontSim User Guide KeywordsWTMULT

447

WTMULT Multiplies a well operating target or limitThis keyword can be used to multiply a control target or limit for a well by a specified factor. The control data must initially have been fully specified using WCONPROD or WCONINJE. This keyword should not be used on a history matching well (see keywords WCONHIST and WCONINJH).





2 Definition of the control or constraint quantity to be changed

ORAT: Oil rate

WRAT: Water rate

GRAT: Gas rate

LRAT: Liquid rate

RESV: Reservoir fluid volume rate


3 Multiplying factor for this quantity.

The units depend upon the quantity chosen. The appropriate units are listed in the specification for keywords WCONPROD and WCONINJE.

End data record with a slash (/). End the set of records with a blank record, containing just a slash.

See also keyword WELTARG.

Example


SPECIALx FRONTSIM


x SCHEDULE

WTMULTPROD1 ORAT 1.5 /PROD2 RESV 0.8 //

448 Keywords FrontSim User GuideWTRACER

WTRACER Sets tracer concentrations for injection wellsThis keyword specifies the value of the concentration of a tracer in the injection streams of its associated phase. If a tracer does not appear in the list of tracer names in the WTRACER keyword, a concentration of 0.0 is assumed.





2 Name of the tracer.

(Up to 3 characters)

3 Value of the tracer concentration in the injection stream,


4 1*

End data record with a slash (/). End the set of records with a blank record, containing just a slash (/).

Example


SPECIALx FRONTSIM


x SCHEDULE

Tconc

WTRACERINJ1 WT1 1.0 /INJ1 WT2 0.0 /INJ2 WT1 0.0 /INJ2 WT2 1.0 /INJ3 IGS 1.0 //

FrontSim User Guide KeywordsZCORN

449

ZZCORN Depths of grid block corners

Each grid block has 8 corners. This keyword enables the depths of each corner of each grid block to be separately specified. It is used for specifying depths for corner point geometry.

As the data for this keyword can be quite voluminous, it is suggested that the data should be prepared using a grid pre-processor (such as GRID or FloGrid).

The keyword line is followed by

2 * NDIVIX * 2 * NDIVIY * 2 * NDIVIZ

values, with the two corners in the i direction of the first grid block being specified first, then two corners for the next block in the i direction, and so on. The last value is followed by a slash (/).


• DEFAULT: <undefined>

If a BOX keyword has been used prior to ZCORN, the ZCORN data should only apply to the current BOX. The keyword must be followed by

2 * NDX * 2 * NDY * 2 * NDZ

values, where NDX, NDY, NDZ are the dimensions of the current box.

ExampleHere NDIVIX = 3, NDIVIY = 2, NDIVIZ = 2:


SPECIALx FRONTSIM

RUNSPECx GRID


ZCORN24*100024*102024*102024*1040 /

450 Keywords FrontSim User GuideZCRIT

ZCRIT Critical Z-factorsIn a run with components, this keyword associates a critical Z-factor with each component.

These Z-factors are used to determine critical molar volumes using the relationship .


Example


SPECIALx FRONTSIM

RUNSPECGRIDEDIT


ZCRIT1.0 0.96 0.994 0.991 /

Nc

Vc ZcRTc Pc⁄=

FrontSim User Guide KeywordsZCRITVIS

451

ZCRITVIS Critical Z-factors for viscosity calculations In a run with components, this keyword associates a critical Z-factor with each component, to be used for viscosity calculations only.

These Z-factors are used to determine critical volumes for use in the Lorentz-Bray-Clark viscosity correlation, using the relationship .

If VCRITVIS or ZCRITVIS is not entered, then values entered with VCRIT or ZCRIT is used. The form of ZCRITVIS is the same as that of ZCRIT.



SPECIALx FRONTSIM

RUNSPECGRIDEDIT


Nc

Vc ZcRTc Pc⁄=

452 Keywords FrontSim User GuideZMF

ZMF Specifies cell initial total composition explicitly This keyword specifies the initial total composition values for each cell. The keyword should be followed by values in normal order, with the X index changing fastest. For thermal runs with water, extra values are required specifying the initial water composition for each cell.

This keyword is normally used to specify the initial solution explicitly, as an alternative to equilibration using EQUIL, the usual method of initializing a compositional run. Explicit initialization is expected if the PRESSURE keyword is present.

An alternative use of the keyword is to overwrite the hydrocarbon composition in a case that has been equilibrated. This can be useful as the equilibration process generates the water saturations, but you may want a non-equilibrium start to handle areal variations in composition. In the case this the ZMF keyword is used with the EQUIL keyword (not with the PRESSURE keyword). If this option is used then the usual data for equilibration (for example, ZMFVD) must be entered to obtain the initial equilibrium solution.

ZMF values that do not sum to 1.0 are normalized provided the error is less than 10%. An error greater than 10% is flagged as a data error.

Example


SPECIALx FRONTSIM



ZMF324*0.0021324*0.0294324*0.6599324*0.0869324*0.0591324*0.0967324*0.0472324*0.0153324*0.0034 /

Nx Ny Nz Nc⋅ ⋅ ⋅

Nx Ny Nz⋅ ⋅

FrontSim User Guide KeywordsZMFVD

453

ZMFVD Total composition with respect to depth tables The data comprises a table of total composition with respect to depth data for each equilibration region. Each table consists of columns of data, and is terminated with a slash (/).

Column: 1

Depth values. The values should increase monotonically down the column.

Column 2 to

The corresponding values of , the total phase mole fractions. The mole fractions specified must add up to unity, and the program checks that this is the case.

For depth values outside the interval specified, constant value extrapolation is performed. If the composition is independent of depth, only a single row is required.

The default maximum number of lines of ZMVFD data is 50.

See also "Initial composition with respect to depth" in the "FrontSim Technical Description".

Note FrontSim currently handles only a single equilibration region.

ExampleIn this case a constant composition with respect to depth for 2 equilibration regions, with a 9-component system:


SPECIALx FRONTSIM

RUNSPECGRIDEDIT


ZMFVD1000.0 0.0121 0.0194 0.6597 0.0869 0.0591

0.0967 0.0472 0.0153 0.0034 /10000.0 0.0121 0.0194 0.6597 0.0869 0.0591

0.0967 0.0472 0.0153 0.0034 /

Nc 1+

Nc 1+

zi Nc

454 Keywords FrontSim User GuideZMFVD

FrontSim User Guide TutorialsIntroduction

455

Chapter 7Tutorials

IntroductionThe aim of this section is to demonstrate how FrontSim is used and to familiarize users with the facilities available.

Precise instructions are provided for each step of the tutorial, whilst input data and examples of the expected output are reproduced within this document where appropriate.

Each tutorial is divided into a number of distinct sections intended to highlight a specific aspect of the analysis process.

Available tutorial1 "Workflow for a Simulation Case" on page 456.

This tutorial demonstrates the use of FrontSim as a tool to aid with simulations. It shows a practical workflow to create data sets and visualize simulation results from FrontSim.

456 Tutorials FrontSim User GuideWorkflow for a Simulation Case

Workflow for a Simulation Case

ObjectiveThis tutorial is designed to demonstrate use of the FrontSim simulator as a tool to help with simulations. It shows a practical workflow to create data sets and visualize simulation results from FrontSim. This tutorial gives an example of how FrontSim can work with ECLIPSE to complete a simulation more efficiently.

Stages• "Case design" on page 456

• "Building a simulation model" on page 457

• "Running a history matching simulation" on page 459

• "Simulation of production prediction" on page 462

• "Viewing results" on page 464

• "Optimized Prediction Simulation" on page 467

• "Results" on page 469.

Case designThis tutorial is designed for those who are familiar with the basic ECLIPSE pre- and post-processors, such as FloGrid, Schedule, FloViz and ECLIPSE Office. However, it can still be applied if you are not familiar with or do not have available the additional products listed above.

The aim of this project is to perform a simulation on a two phase (oil and water) system in a heterogeneous reservoir in order to design optimum well control for future production. To demonstrate the workflow, a medium sized model, of approximately 150,000 active cells, is built; most typical FrontSim models are of the order of 105-106 cells.

You will use auxiliary information from other tutorials:

• Reservoir geological model in a rescue file format

• Well trajectories

• Details of well perforations and other well events, and production history

• Information on initial reservoir conditions and fluid properties.

Scenario• Simulation start date 1 January 1994

• History matching to 31 December 1999

• Prediction from 1 Jan 2000 to 1 January 2006

• The end of prediction simulation is 1 Jan 2006

FrontSim User Guide TutorialsWorkflow for a Simulation Case

457

• The dimensions of the grid are 43 X 60 X 82. The total grid is made up of 211560 cells, of which 150094 cells are active.

• There is an active edge water drive that is modeled using an infinite Carter-Tracy aquifer

• FIELD units are used.

• The phases present are OIL and WATER.

• There are 10 history production wells and 4 history injection wells

• A new horizontal production well and a new injection become active on 1 January 2001.

The simulation is divided into two main parts: history matching and prediction. After 6 years’ production history, you will optimize the plan for the next 6 years’ production by selecting a location to drill a new injection well. You can also vary the production and injection rates.

Building a simulation model

Tutorial data filesThe tutorial data files are included with your FrontSim installation.

1 Create a working directory in a convenient place and copy all files in /ecl/2007.1/FrontSim/tutorials/workflow directory to this directory

2 It should include the following sub-directories:

a data directory: containing the following data files BASE_FS.DATA, BASE_FS_HIST.X0024, BASE_ECL.DATA and BASE_ECL_HIST.X0024.

b grid directory: containing the following data files BASE.GRDECL

c schedule directory: containing the following data files BASE.NET, BASE.TRJ, PRED2.TRJ, BASE.VOL, BASE_HIST.EV, BASE_PRED.EV, BASE_HIST.TFW, BASE_PRED.TFW, BASE_HIST.SCH, BASE_PRED1.SCH, and BASE_PRED2.SCH.

Generating a GRID and INIT filesThis tutorial uses a cloudspin case as a geological model. We do not intend to show you in detail how to build a simulation grid from this geological model using FloGrid. Please refer to the FloGrid tutorial "Building a simulation model from a RESCUE model" on page 46 of the "FloGrid User Guide".

1 Start FloGrid from the ECLIPSE Launcher on PC (or @flogrid on UNIX) in your grid directory.

2 Load the RESCUE file and generate a GRID file. This step is optional as a model has been generated for you.

a The original geometry RESCUE file, BASE.BIN, can be found in the FloGrid Tutorial 2 directory. Follow the procedure shown in the FloGrid tutorial mentioned above to load the RESCUE file and generate an ECLIPSE-style GRID file.

Note The FloGrid tutorial fine model has been generated for you: a reservoir geometry file BASE.GRDECL (in the grid directory). This is a structured corner-point geometry model with the same number of grid cells as the original geological model.


3 To generate the Schedule section for the data set it is first necessary to generate .GRID and .INIT files. You need to run a NOSIM case:, you can do this simply by running BASE_FS.DATA. Run this file using FrontSim from the ECLIPSE Launcher on PC (or @frontsim on UNIX).

This generates files BASE_FS.GRID and BASE_FS.INIT. Both the GRID and INIT files generated should be moved into the schedule subdirectory.

Generating a SCHEDULE sectionIn this section you are shown how to use Schedule to import and edit some existing files to generate a SCHEDULE section for FrontSim. For more details on how to use Schedule, please refer to the "Tutorials" on page 17 of the "Schedule User Guide".

Note If you are familiar with the Schedule program, you can go directly to the next step "Running a history matching simulation" on page 459.

1 Start Schedule from the ECLIPSE Launcher on PC (or @schedule on UNIX) in your schedule directory.

Creating a new Schedule project2 Schedule: File | Save As...

a Enter HIST and click on OK.

This saves the current project named HIST.PRJ

Importing existing files1 Import the production data using Schedule: Import | Production History | Replace and

select BASE.VOL.

2 Import the events data using Schedule: Import | Events | Replace and select BASE_HIST.EV.

3 Import a grid using Schedule: Import | Grid | Single Porosity and select BASE_FS.GRID.

4 Import the well trajectory data using Schedule: Import | Well Locations | Trajectory File and select BASE.TRJ.

5 Import the control network data using Schedule: Import | Control Network and select BASE.NET.

6 Import the Time Framework using Schedule: Import | Time Framework | Replace and select BASE_HIST.TFW.

7 Import Properties. Schedule: Import | Properties and select BASE_FS.INIT.

The original production data (BASE.VOL) is given on a monthly basis. The speed of FrontSim is partly dependent on timestep lengths. This is because if any time well conditions are changed, FrontSim has to re-solve the pressure equation. Therefore, FrontSim is forced to take a time step each time a WCONHIST keyword is given. By averaging the production rates over longer time steps, such as quarterly or half year timesteps, some speed advantage can be obtained.

Checking that the production data is averaged over quarterly timesteps1 Select Schedule: Setup | Time Framework.

a Ensure 3 Months is entered in the Step By column, and click on OK.


459

Hint You can export the averaged production data by selecting Schedule: Export | Production History | TimeFrame and saving the file, as AVE for example. It will generate a new production file named AVE.VOL with production data averaged in each 3 months.

Exporting the SCHEDULE section1 Schedule: Export | Schedule Section.

a Save the file with the name HIST and click on Save, which gives an output of the SCHEDULE section named HIST.SCH.

Saving the project1 Schedule: File | Save.

2 Schedule: File | Exit to close the window.

Running a history matching simulation1 In the data directory:

a Copy BASE_FS.DATA to FS_HIST.DATA

b Copy BASE_FS.DATA to ECL_HIST.DATA

c Remove the NOSIM keyword from the RUNSPEC section of FS_HIST.DATA and ECL_HIST.DATA

d Make sure the files BASE.GRDECL and HIST.SCH are included in the GRID and SCHEDULE sections respectively.

Note If you cannot generate a SCHEDULE section for some reason, then the standard data file BASE_HIST.SCH in the schedule directory can be used in the simulations.

There are a several keywords that are important in controlling the output and equation solvers in FrontSim. These are briefly described below. Please see the individual descriptions of the keywords in this User Guide for more detail.

2 Open the FrontSim data set using a standard editor, and check the following:

a The RPTRST keyword should be set at the beginning of the SCHEDULE section to produce RESTART files and streamline output files.

Note A RESTART file may be output either in multiple or in unified style (.X000n or .UNRST), but the streamline files can only be output in multiple style (.SLN000n).

Note Unlike ECLIPSE, FrontSim does not support formatted output. If you need to view formatted SUMMARY files or RESTART files, use the macros $convert (PC) or @convert (UNIX). Note that .SLN000n files cannot be converted to formatted output.


• Keywords RPTSCHED in SCHEDULE section sets the frequency of the print file reports and other relevant reports.

• Keyword RPTLINFS controls the frequency for line graph output from the simulator to the SUMMARY files.

• Keyword OPTIONFS controls special options within particular facilities in FrontSim. These options are mainly of a temporary or experimental nature, or act to restore back-compatibility with earlier versions of the code.

• Keyword FSSOLVE controls which pressure solver to use. The default is the AMG, Algebraic MultiGrid solver. It is faster; however it is only valid for compressible runs.

• Keyword TUNEFS1D controls the tuning options for the 1D solver used on streamlines for 3-phase and compositional runs.

• Keyword TUNEFSSA controls the tuning options of the pressure and saturation solver in FrontSim. In this case we set item 6 to NO to save the run memory required. This option controls whether streamlines are saved in memory in case they are needed for more than one step (that is, no pressure solve, but gravity steps). Setting this to NO might slightly increase the CPU running time.

• Keyword TUNEFSPR determines the frequency with which the pressure field is updated, and controls the tuning options of the pressure solver. Unlike traditional finite-difference simulators, you must decide the frequency with which the pressures are updated. If production data of active wells changes, then the pressure field is automatically recalculated.

Hint The ECLIPSE keywords SKIP100 and ENDSKIP cause ECLIPSE to skip reading the data between these keywords. In this manner a dataset can be created that can be run using either FrontSim or ECLIPSE. They are ignored by FrontSim.

3 Start FrontSim from the ECLIPSE Launcher on PC (or @frontsim on UNIX) and run FS_HIST.

4 Start ECLIPSE from the ECLIPSE Launcher on PC (or @eclipse on UNIX) and run ECL_HIST.

Note This is a large model. FrontSim takes 31 minutes to run it and ECLIPSE 41 minutes, on a 1.8 GHz Pentium 4 PC.

Viewing simulation results using FloVizViewing the results from a streamline simulation is somewhat different from viewing traditional finite difference simulator results. You now have access to two sorts of data: grid data and streamline data. Both of these are useful in interpreting the results of the simulation. In this part of the tutorial, we will only examine the grid type data.

1 Start FloViz from the ECLIPSE Launcher on PC (or @floviz on UNIX). Select your data directory.

2 FloViz: File | Open | Eclipse.... Select FS_HIST.GRID from the file browser and click on OK. This opens the Import Properties & Wells panel.

a Click on OK to load in the grid, solution, and streamlines. It displays a 3D field viewing oil saturation by default.


461

Figure 7.1 shows the last timestep of history matching. It seems there is high oil saturation in most of the field area.

Figure 7.1 Oil Saturation at the end of production history

Viewing simulation results using ECLIPSE Office1 Start ECLIPSE Office from the ECLIPSE Launcher on PC (or @office on UNIX).

2 On the main ECLIPSE Office panel, select Module | Results Viewer...

3 Choose File | Open | Summary | Load All Vectors and select FS_HIST.SMSPEC

4 Choose LinePlot | User...

a In the Results Viewer Summary Section panel create a plot of FOPT and FWCT versus time.

Figure 7.2 shows the field cumulative oil production (FOPT) and field water cut (FWCT) with time in a history matching run by FrontSim.


Figure 7.2 Plot of dimensionless oil recovery and water cut for production

Simulation of production prediction

Initial prediction simulationThe production over the last 6 years has not been particularly efficient. The OIIP is 212M Mstb, of which 18.6M Mstb has been produced: only 8.8%.

Prediction designA field production target of 30000 stb/day liquid from the beginning of year 2000 is defined. In 2001 with the addition of 1 new horizontal well this is increased to 35000 stb/day. The water injection rate in field is 40000 stb/day rising to 55000 stb/day with the addition of one new vertical injection well in 2001.

Field oil production rate of 30000 stb/day is obtained by specifying a rate of 3000 stb/day for each of the ten wells. 10000 stb/day water is injected through each of the four injection wells. An additional 5000 stb/day of liquid is produced from the new horizontal well and 15000 stb/day of water is injected in the new water injection well from 1 January 2001 until the end of simulation on 1 January 2006.


463

Generating a SCHEDULE sectionFor the prediction run, we need a new SCHEDULE section. This can be done by updating the well events and time framework in the original Schedule project.

1 Start Schedule from the ECLIPSE Launcher (or @schedule on UNIX) in your schedule directory.

2 Open the existing project: Schedule: File | Open.

a Select HIST.PRJ from the file browser and click on the Open button.

3 Create a new Schedule project: File | Save as..., type PRED1 (PRED1.PRJ).

4 Import the new events data Import | Events | Replace BASE_PRED.EV and the new time framework Import | Time Framework | Replace BASE_PRED.TFW to replace the original ones.

5 Export the SCHEDULE section with the name PRED1 (PRED1.SCH).

6 Save the project and exit Schedule.

Note If you cannot generate a SCHEDULE section for some reason, then the standard data file BASE_PRED1.SCH in the schedule directory can be used in the simulations.

Running a prediction simulation in FrontSim

Editing the FrontSim dataset1 In the data directory, copy FS_HIST.DATA to FS_PRED1.DATA.

2 Edit the SOLUTION section in FS_PRED1.DATA by commenting out the EQUIL, AQUCT and AQUANCON keywords, and inserting the RESTART keyword.

Note If you did not get the RESTART file by running the simulation, you can use the file BASE_FS_HIST.X0024 for this run. In this case use BASE_FS_HIST as the parameter for the RESTART keyword.

This sets a restart run on 1 January 2000.

Hint A FrontSim run can also be restarted from an ECLIPSE run, provided that the FIP option was also added to the ECLIPSE RPTRST section for the ECLIPSE run. For more information see the FrontSim RESTART keyword.

SOLUTION--AQUCT-- 1 6800 1* 250 0.20 1.2E-05 6400 100 50 1 1 /--AQUANCON-- 1 43 43 33 50 09 81 'I+' /--/--EQUIL--5560 5000 6555 /RESTARTFS_HIST 24 /


3 Edit the schedule section in FS_PRED1.DATA so as to remove the HIST.SCH and replace this with the new INCLUDE file, PRED1.SCH.

4 Save the data set as FS_PRED1.DATA.

Note If you cannot generate the new SCHEDULE section using Schedule program, you can use the file BASE_PRED1.SCH for this run.

5 Start FrontSim from the ECLIPSE Launcher (or @frontsim on UNIX) and run FS_PRED1.

Note This is a large model. FrontSim takes about 34 minutes to run it on a 1.8 GHz Pentium 4.

Viewing results

Viewing results in ECLIPSE OfficeTo further understand the well production balance, we plot the results versus time in ECLIPSE Office.

1 Start ECLIPSE Office from the ECLIPSE Launcher on PC (or @office on UNIX)

2 Import summary data of FS_PRED1 and load all vectors

3 Plot field and well results for oil production rate, water cut and bottom hole pressure (BHP).

Figure 7.3 displays the oil production rates and water cut for some of the production wells.

We can see that wells P02, P04, P07 and P10 show a significant decrease in oil rate together with an increasing water-cut. Well P07 is particularly bad, reaching almost 75% water cut after only three years. We would like to ascertain from where the water in this well is coming. To do this we will look at the 3D model in FloViz.

SCHEDULEINCLUDE‘../schedule/PRED1.SCH’ /


465

Figure 7.3 Well Oil Production Rate and Water Cut for Prediction run

Viewing results in FloVizIn this part of the tutorial we will examine both the grid and streamline data.

Note This tutorial is not intended to describe the major functionality in the 3D Viewer for displaying streamline data. Please refer to relevant tutorials in FloViz, GridSim or ECLIPSE Office for further details of the 3D Viewers

1 Start FloViz from the ECLIPSE Launcher (or @floviz on UNIX).

2 FloViz: File | Open | Eclipse..., select FS_PRED1.GRID from the file browser and click on OK.

This opens the Import Properties & Wells panel.

3 Click on OK to load in the grid, solution, and streamlines.


The program displays a 3D grid viewing oil saturation by default.

4 For displaying streamline data choose View | Object Appearance and Hide the Grid.

Click on Apply.

Hint Hiding the grid can also be done by deselecting the two buttons and .

The 3D Viewer should now show wells and streamlines. The streamlines display the oil saturation at the first time step (1 Jan 2000). Click on the “Play” button to see how the oil saturation changes along the streamlines.

Hint You can select a specific timestep with FloViz: View | Timesteps.

5 Select FloViz: Scene | Streamlines | Streamline Display. In the pop-up window select TIME_BEG to visualize the time of flight of the streamlines.

Hint Display the Streamline display panel by clicking on .

6 It is necessary to rescale the legend to see better what is happening. To do this, change to the picking mode (OpenInventor), click on the legend and select Edit.

a In the panel Time from Beginning Color Map Editor, click on the radio button Override and select 5000 (days) for maximum; click on APPLY.

Figure 7.4 clearly shows the direct flow from injection well I05 to producing well P07. Reference to the legend shows that the water from I05 takes some 2200 days to reach P07 - thus confirming what we have seen in Figure 7.2, although we now know where the water is coming from. We can see that the aquifer is affecting wells P10, P02 and P06.


467

Figure 7.4 Streamlines at the end of prediction colored by Time of Flight

Optimized Prediction SimulationPart of the optimization will be the relocation of well I05 to the northern section of the model. A further refinement would be to increase the production rates of the wells. It appears that the rates could be significantly increased without a significant increase in water-cut. However, so as to be able to make a direct comparison with the previous prediction run, only the location of the injector will be changed. The exercise of increasing the oil rate is left up to you as an additional exercise.

Generating the SCHEDULE sectionBASE_PRED2.SCH is supplied in the Schedule directory. As this is a FrontSim tutorial, there is no gain from spending a lot of time editing the SCHEDULE section. However, if you want, you can generate it by doing the following:

The new position of injector I05 needs to be updated in the Schedule program for the new prediction. The updated trajectory file can be found in the directory for this tutorial.


1 Start Schedule from the ECLIPSE Launcher (or @schedule on UNIX) in your schedule directory.

2 Create a new Schedule project named PRED2 (PRED2.PRJ).

3 Schedule: File | Open, select PRED1.PRJ from the file browser and click on the Open button.

This loads the PRED1 project.

As we are moving the well, we need to input a new deviation survey; in this case we will load the trajectory file.

4 Schedule: Import | Well Locations | Trajectory file, select BASE_PRED2.TRJ

5 Export the SCHEDULE section with the name PRED2 (PRED2.SCH).

6 Save the project and close the window.

Run optimized simulations on prediction

Editing the FrontSim dataset1 Copy FS_PRED1.DATA to FS_PRED2.DATA.

2 Edit the SCHEDULE section in FS_PRED2.DATA and include the new SCHEDULE section,

a or if you have not edited the Schedule simply use the supplied SCHEDULE section.

3 Save dataset FS_PRED2.DATA

Editing the ECLIPSE datasetThe data sets have been set up so that going from FrontSim to ECLIPSE is simple. You will have noted the SKIP100 and ENDSKIP keywords in the SCHEDULE section. ECLIPSE does not read anything between these two keywords. The FrontSim tuning keywords were placed here.

1 Copy FS_PRED2.DATA to ECL_PRED2.DATA, and open ECL_PRED2.DATA.

SCHEDULEINCLUDE--’../schedule/PRED1.SCH’ /‘../schedule/PRED2.SCH’ /

SCHEDULEINCLUDE--’../schedule/PRED1.SCH’ /‘../schedule/BASE_PRED2.SCH’ /


469

2 Edit the SOLUTION section in FS_PRED2.DATA by commenting out the EQUIL, AQUCT and AQUANCON keywords, and inserting the RESTART keyword.

Note If you did not get the unified restart file by running the simulation, you can use the file BASE_ECL_HIST.X0024 for this run. Note that the RESTART file supplied is in multiple style (.X000n). In this case use BASE_ECL_HIST as the parameter for the RESTART keyword.

3 Save dataset ECL_PRED2.DATA.

4 Start FrontSim from the ECLIPSE Launcher (or @frontsim on UNIX) and run FS_PRED2.

The Log window during the run clearly shows very low material balance errors. We can run the full prediction in ECLIPSE to compare simulation results.

5 Start ECLIPSE from the ECLIPSE Launcher (or @eclipse on UNIX) and run ECL_PRED2.

Results

Viewing the results in FloViz and Office1 Use the 3D viewer for displaying streamline data results from FrontSim.

2 Use the Results viewer of ECLIPSE Office to display the individual well results

CommentsThe results of PRED2 show a significantly lower water cut in well P07.

The placement of well I05 has increased the drainage of this area. The effect of this well can be seen by examining the oil saturation streamlines at the end of the simulation. The production rate of the wells that are not cutting water cut could be increased, thus accelerating production.

The running times of FrontSim are significantly faster than those of ECLIPSE, and thus allow different scenarios to be examined in a short time. The streamlines generated by FrontSim have allowed the source of the produced water to be identified, and improve the well locations.

SOLUTION--AQUCT-- 1 6800 1* 250 0.20 1.2E-05 6400 100 50 1 1 /--AQUANCON-- 1 43 43 33 50 09 81 'I+' /--/--EQUIL--5560 5000 6555 /RESTARTECL_HIST 24 /

FrontSim User Guide Retired KeywordsKeywords retired in 2003A release

471

Appendix ARetired Keywords

Keywords retired in 2003A releaseIEQUIL: This keyword is replaced by setting item 9 of keyword EQUIL to 0, for compatibility with ECLIPSE.

472 Retired Keywords FrontSim User GuideKeywords retired in 2002A release

Keywords retired in 2002A releaseThe following keywords were removed from the 2002A manual, and superseded by the new keywords shown.

The following keyword has had its definition significantly changed in 2002A release:

Caution Keywords from 99B and earlier releases cannot be mixed with keywords from 2000A and later releases.

Table A.1 Changed keywords

Old NewFSRECALC

TUNING

TUNEFSPR

FSTUNE TUNEFSSA

FSTUNE1D TUNEFS1D

FSWSTRM WELSTRDN

FSRPGRPH RPTLINFS

OPTIONFS

Table A.2 Keyword significantly changed in 2002A release

Old ChangedRPTRST RPTRST

FrontSim User Guide UnitsThe unit conventions

473

Appendix BUnits

The unit conventionsThere are four unit conventions currently used:

• METRIC units

• FIELD unitsNot used in FrontSim • LAB unitsNot used in FrontSim • PVT-Metric units (in ECLIPSE 300 only)

The LAB convention is intended for use when simulating laboratory-scale experiments. It is based on the original Darcy units, except that the unit of time is the hour rather than the second. The units for each data quantity are given in Table B.1.


SPECIALx FRONTSIM

Table B.1 A table of the units used for four conventions

Quantity Metric Field Lab PVT-MLength, depth, radius m ft cm m

Time day day hr day

Density kg/m3 lbm/ft3 g/cc kg/m3

Pressure (absolute) Barsa Psia Atma Atma

Pressure (difference) Bars Psi Atm Atm

Temperature (absolute)

Temperature (difference)

Compressibility 1/Bars 1/Psi 1/Atm 1/Atm

Viscosity cpoise cpoise cpoise cpoise

Permeability MDarcy MDarcy MDarcy MDarcy

Liquid surface volume sm3 stb scc sm3

Gas surface volume sm3 Mscf* scc sm3

°K °R °K °K

°C °F °C °C

474 Units FrontSim User GuideThe unit conventions

ConstantsTable B.2 gives the values of some principal constants in the four unit conventions.

Standard conditions are taken as one atmosphere and .

Reservoir volume rm3 RB rcc rm3

Liquid surface volume rate sm3/day stb/day scc/hr sm3/day

Gas surface volume rate sm3/day MScf/day scc/hr sm3/day

Reservoir volume rate rm3/day RB/day rcc/hr rm3/day

Formation volume factor (liquid) rm3/sm3 RB/stb rcc/scc rm3/sm3

Formation volume factor (gas) rm3/sm3 RB/Mscf rcc/scc rm3/sm3

Gas-oil ratio sm3/sm3 Mscf/stb scc/scc sm3/sm3

Oil-gas ratio sm3/sm3 stb/Mscf scc/scc sm3/sm3

Transmissibility cp.m3/day/Bar cP.RB/day/Psi cP.cm3/hr/Atm cP.m3/day/Atm

*.In the Field Units system the prefix M conventionally signifies a multiple of one thousand, and MM onemillion. In the other units systems the SI standards of k for one thousand and M for one million are used.

Table B.2 Constants used in the four unit conventions

Quantity Metric Field Lab PVT-MGravity constant 0.0000980665 0.00694444 0.000967841 0.0000967841

Darcy constant 0.00852702 0.00112712 3.6 0.00864

Atmospheric pressure

1.01325 14.6959 1.0 1.0

Density of air 1.2232 0.076362 0.0012232 1.2232

Density of water 999.014 62.3664 0.999014 999.014

Gas constant, R 0.083143 10.732 820.55776 0.08205576

Table B.1 A table of the units used for four conventions (Continued)

Quantity Metric Field Lab PVT-M

60°F

FrontSim User Guide UnitsConversion factors

475

Conversion factorsTable B.3 gives some useful conversion factors between the unit systems.

API gravityAPI gravity = (141.5 / liquid gravity) - 131.5

Conversion for an ideal gas (Z=1)For an ‘ideal gas’ Z-factor of unity, we can use the ideal gas equation:

[EQ B.1]

where:

is pressure

is volume

is number of moles

is the gas constant

is temperature

Using [EQ B.1], we can calculate the following:

• When and ,

• the volume occupied by one mole of gas is:

[EQ B.2]

Table B.3 Some useful conversion factors

Quantity Metric Field Other unitsLength 1 m

0.3048 m

=3.28084 ft

=1 ft

Volume 1 m3

0.02831685 m3

=35.31466 cf

=1 cf

=6.289811 bbl

=0.1781076 bbl

Mass 1 kg

0.45359237 kg

= 2.204623 lb

=1 lb

Density 1 kg/m3

16.01846 kg/m3

=0.06242797 lb/ft3

=1 lb/ft3

=10-3 g/cm3

=0.01601846 g/cm3

Pressure 1 bar

0.06894757 bar

=14.50377 psi

=1 psi

=0.986923 Atm

=0.068046 Atm

Gas-liquid ratio 1 m3/m3

178.1076 m3/m3

= mcf/Mscf

=1 mcf/bbl

Temperatures =

5.614583 10 3–⋅

TK T 1.8⁄( )°R

PV nRT=

P

V

n

R

T

P 14.7psia= T 519.67°R=

Vmolar 379.39445ft3=

476 Units FrontSim User GuideConversion factors

• the number of moles in unit volume is:

[EQ B.3]

• When and ,

• the volume occupied by one mole of gas is:

[EQ B.4]

• the number of moles in unit volume is:

[EQ B.5]

nmoles 0.00263578mol=

P 1.013Bar= T 288.15K=

Vmolar 23.650203 10 6– m3×=

nmoles 0.04228293mol=

FrontSim User Guide Bibliography 477

Appendix CBibliography

Bratvedt, F., Bratvedt, K., Buchholz, C.F., Holden, L., Holden, H. & Risebro, N.H.

A New Front-Tracking Method for Reservoir Simulation, SPE 19805 [Ref. 1]

SPE Reservoir Engineering, 7, Page 107-116, , February 1992

Bratvedt, F., Bratvedt, K., Buchholz, C. F., Gimse, T., Holden, L, Holden, H. and Risebro, N. H.

FRONTLINE and FRONTSIM. Two Full Scale, Two-Phase, Black Oil Reservoir Simulators Based on Front Tracking [Ref. 2]

Survey of Math. Ind., 3, Page 185, 1993

Sovold, K, Rian, D.T., & Sandvik, A.

Front Tracking Applied to the Simulation of Water Flooding in a Braided River System. [Ref. 3]

SPE 21084, October 1990

Rian, D.T., & Hage, A. Automatic Optimization of Well Locations in a North Sea Fractured Chalk Reservoir Using a Front Tracking Reservoir Simulator. [Ref. 4]

SPE 28716, October 1994

Tyrie, J.J., Gimse, T. Some Powerful Reasons for Adopting Front Tracking Simulation [Ref. 5]

SPE 30444, September 1995

Giordano, R.M., Redman, R,S. & Bratvedt, F.

A New Approach to Forecasting Miscible Water Alternating Gas Performance at the Field Scale, SPE 36712 [Ref. 6]

SPE Reservoir Evaluation & Engineering , Page 192-200 , March 1998. First presented to SPE in October 1996.

Emanuel, A.S. & Milliken, W.J.

History Matching Finite Difference Models with 3D Streamlines [Ref. 7]

SPE 49000 , September 1998

Grinestaff, G.H. Waterflood Pattern Allocations: Quantifying the Injector to Producer Relationship with Streamline Simulation [Ref. 8]

SPE 54616 , May 1999

478 Bibliography FrontSim User Guide

Grinestaff, G.H & Caffrey, D.J

Waterflood Management: A Case Study of the Northwest Fault Block Area of Prudhoe Bay, Alaska, Using Streamline Simulation and Traditional Waterflood Analysis [Ref. 9]

SPE 63152 , October 2000

Chakravarty, A., Liu, D.B., Scott Meddaugh, W.

Application of 3D Streamline Methodology in the Saladin Reservoir and Other Studies [Ref. 10]


Milliken, W.J., Emanuel, A.S. & Chakravarty, A.

Applications of 3D Streamline Simulation to Assist History Matching [Ref. 11]


Crane, M., Bratvedt, F., Bratvedt, K.,Childs, P. & Olufsen, R.

A Fully Compositional Streamline Simulator [Ref. 12]


Lolomari, A., Bratvedt, K., Crane, M., Milliken, W.J.,Tyrie, J.J.

The Use of Streamline Simulation in Reservoir Management: Methodology and Case Studies [Ref. 13]


Smoller, J. Shock Waves and Reaction-Diffusion Equations [Ref. 14]

Springer Verlag, 1983

Dafermos, C.M. Polygonal Approximation of Solutions of the Initial Value Problem for a Conservation Law [Ref. 15]

Journal of Mathematics, 38, Page 33-41, 1972

Bratvedt, F., Gimse, T. and Tegnander, C.

Streamline computations for porous media flow including gravity [Ref. 16]

Transport in Porous Media, 1996

King, M. J. and Datta-Gupta, A.

Streamline simulation: A current perspective [Ref. 17]

In Situ, 22(1), Page 91-140, 1998

Fetkovich, M. J. A Simplified Approach to Water Influx Calculations - Finite Aquifer Systems [Ref. 18]

J. Pet. Tech, Page 814-828, July 1971

Carter, R. D. and Tracy, G. W.

An Improved Method for Calculating Water Influx [Ref. 19]

Trans. AIME 219; J. Pet. Tech, Page 58-60, Dec. 1960

Martin, J. J. Cubic Equations of State-Which? [Ref. 20]

I and EC Fundamentals, Vol. 18, Page 81, May 1973

Coats, K. H. Simulation of Gas Condensate Reservoir Performance [Ref. 21]

SPE paper no. 10512, presented at the Sixth SPE Symposium on, Reservoir Simulation, New Orleans, 1982

FrontSim User Guide Bibliography 479

Michelsen, M. L. The isothermal flash problem. Part I. Stability [Ref. 22]

Fluid Phase Equilibria Vol 9, Page 1-19, 1982

Dennis, J. E. and Schnabel, R. B.

Numerical Methods for Unconstrained Optimization and Nonlinear Equations [Ref. 23]

Prentice-Hall, 1983

Crowe, C. M. and Nishio, M

Convergence Promotion in the Simulation of Chemical Processes - The General Dominant Eigenvalue Method [Ref. 24]

AIChEJ, Vol. 23, No. 3, Page 528-529, May 1975

Aziz, K. and Settari, A. Petroleum Reservoir Simulation [Ref. 25]

Applied Science Publishers, London, Page 398, 1979

Stone, H. L. Probability Model for Estimating Three-Phase Relative Permeability [Ref. 26]

Trans AIME (JPT), 249, Page 214-218, , 1970

Stone, H. L. Estimation of Three-Phase Relative Permeability and Residual Oil Data [Ref. 27]

Can.Pet.Tech., Vol 12, , Page 53-61, , 1973

Haaland, S.E. Journal of Fluids Engineering, volume 105 [Ref. 28]

Trans. ASME, Page , 89, 1983

Welty, J.R., Wicks, C.E., and Wilson, R.E.

Fundamentals of Momentum Heat and Mass Transfer [Ref. 29]

John Wiley and Sons, 1984

Gunasekera, D., Childs, P., Cox, J. and Herring, J.

A Multi-Point Flux Discretization Scheme for General Polyhedral Grids [Ref. 30]

SPE 48855, International Oil & Gas Conference and Exhibition, Beijing, China, 1998

Aavatsmark, I., Barkve, T. and Mannseth, T.

Control-Volume Discretization Methods for 3D Quadrilateral Grids in Inhomogeneous, Anisotropic Reservoirs [Ref. 31]

SPE 38000, SPE Reservoir Simulation Symposium, Dallas, Texas, June 1997

Pollock, D. W. Semianalytical Computation of Path Lines for Finite Difference Models [Ref. 32]

Ground Water, 26(6) , Page 743-750 , (1988)

Prévost, M., Edwards, M.G. and Blunt, M.J.

Streamline Tracing on Curvilinear Structured and Unstructured Grids [Ref. 33]

SPE Journal 7(2) , Page 139-148 , 2002

G. H. Grinestaff, Thiele, Marco R., Batycky, Rod P.

Water Injection Optimization Using Streamline-Based Workflow [Ref. 34]

SPE 84080 , Page , date of publication Antonina Kozlova et. al.

A Three-Phase Compressible Dual-Porosity Model for Streamline Simulation [Ref. 35]

SPE102549, 2006

480 Bibliography FrontSim User Guide

FrontSim User Guide Index 481

Appendix DIndex

AACF. . . . . . . . . . . . . . . . . 77

Active Grid Blocks . . . . . . 78

ACTNUM . . . . . . . . . . . . 78

ADD . . . . . . . . . . . . . . . . 79

Adsorption function. . . . . 349

AMG Solver . . . . . . . . . . 162

Analytic Aquifer . . . . 81 to 82

AQANTRC . . . . . . . . . . . 81

AQUANCON . . . . . . . . . . 82

AQUCON . . . . . . . . . . . . 89

AQUCT . . . . . . . . . . . . . . 84

AQUFETP . . . . . . . . . . . . 86

AQUFLUX . . . . . . . . . . . 88

AquiferAnalytic . . . . . . 81 to 82Fetkovich . . . . . . . . . 86Numerical . . . . . . 89, 91

AQUNUM . . . . . . . . . . . . 91

AQUTAB . . . . . . . . . . . . . 93

Artificial Lift Quantity391 to 392

BBalance error, material. . . 163

BIC . . . . . . . . . . . . . . . . . 94

Boundary condition, pressure272 to 273

Boundary, pressure. . . . . . 265

BOX . . . . . . . . . . . . . . . . . 95

Bubble Point Pressure247 to 248, 307

CCapacity, heat . . . . . . . . . 183

Capillary PressureGas-Water . . . . . . . . 146Oil-Gas . . . . . . . . . . 321Oil-Water . . . . . . . . . 146Water-Gas . . . . . . . . 250Water-Oil . 250, 339, 344

CARFIN . . . . . . . . . . . . . . 96

CECON . . . . . . . . . . . . . . 98

CECONINJ . . . . . . . . . . . 100

CellInactive78, 209, 264, 266 to 267Matrix . . . . . . . . . . . 121

CNAMES . . . . . . . . . . . . 102

COMPDAT . . . . . . . . . . . 103

COMPDATL . . . . . . . . . . 106

Completion Specification103, 106

COMPLUMP . . . . . . . . . 107

COMPORD. . . . . . . . . . . 109

COMPS . . . . . . . . . . . . . 111

Connate water saturationscaled . . . . . . . . . . . 343

ConnectionAnalytic Aquifer . . . . 82Non-Neighbor . . . . . 129Numerical Aquifer. . . 89Well . . . . . .98, 100, 421

ContactGas-Oil. . . . . . . . . . 146Gas-Water. . . . . . . . 146Water-Oil . . . . . . . . 146

ControlInjection . . . . . . . . . 166Injection Well . . . . . 401Output . . . . . . .305, 316Pattern Flood Injection Well406Production . . . .168, 412

COORD. . . . . . . . . . . . . .112

Coordinate System . . . . . . 27

COORDX . . . . . . . . . . . .113

COORDY . . . . . . . . . . . .113

COORDZ . . . . . . . . . . . .113

COPY . . . . . . . . . . . . . . .114

Corner Point Geometry . . 449

Crossflow . . . . . . . . . . . 425

DDATES . . . . . . . . . . . . . .116

DATUM . . . . . . . . . . . . .117

Dead Oil . . . . . . . . . . . . 307

482 Index FrontSim User Guide

DENSITY . . . . . . . . . . . . 118

Density, streamline . . . . . .427

DepthCorner Point . . . . . . .449Corrected Pressure . . 117Datum . . . . . . . . . . .146

Depth difference. . . . . . . .357

DEPTHZ . . . . . . . . . . . . . 119

Dew Point Pressure. . . . . .252

D-Factor . . . . . . . . . . . . .104

DIMENS . . . . . . . . . . . . .120

Dimensionswell data. . . . . . . . . .419

Dissolved Gas . . . . .279, 307

Downtime . . . . . . . . . . . .417

DPGRID . . . . . . . . . . . . .121

DPNUM . . . . . . . . . . . . .123

DRSDT . . . . . . . . . . . . . .122

DRVDT. . . . . . . . . . . . . .124

Dry Gas . . . . . . . . . .274, 312

Dual Porosity . . 121, 123, 325

DUALPORO . . . . . . . . . .125

DUMPFLUX . . . . . . . . . .126

DXV . . . . . . . . . . . . . . . .127

DYV . . . . . . . . . . . . . . . .127

DZV . . . . . . . . . . . . . . . .128

EEconomic Limit98, 100, 170, 414, 416

EDITNNC . . . . . . . . . . . .129

Efficiency Factor . . . . . . .417

END . . . . . . . . . . . . . . . .130

End Point Scaling134 to 136, 138, 191, 193, 195, 197, 199, 201, 203, 315

Debug function . . . . .141

ENDBOX . . . . . . . . . . . .131

ENDFIN . . . . . . . . . . . . .132

ENDINC . . . . . . . . . . . . .133

ENDNUM . . . . . . . . . . . .134

ENDSCALE . . . . . . . . . .135

ENKRVD . . . . . . . . . . . .136

ENPTVD . . . . . . . . . . . . .138

EOS . . . . . . . . . . . . . . . . 140

EPSDEBUG . . . . . . . . . . 141

EQLNUM . . . . . . . . . . . 143

EQUALS . . . . . . . . . . . . 144

EQUIL . . . . . . . . . . . . . . 146

Equilibration117, 143, 248, 252, 313, 339

EXCEL . . . . . . . . . . . . . 150

FFault . . . . . . . . . . . . . . . 129

FAULTS. . . . . . . . . . . . . 151

FDM9PNT . . . . . . . . . . . 153

Fetkovich Aquifer . . . . . . . 86

FIELD . . . . . . . . . . . . . . 154

FilesLine Graph . . . . . . . . 23RFT . . . . . . . . . . . . 441Text . . . . . . . . . . . . . 21

Finite difference method . 153

FIPNUM . . . . . . . . . . . . 155

Fluids In Place . . . . . . . . 147

FluxRegion . . . . . . 156, 218

Fluxesvolumetric . . . . . . . . 158

FLUXNUM . . . . . . . . . . 156

FLUXSIDE . . . . . . . . . . 158

FLUXTYPE . . . . . . . . . . 160

Frequency, reports . . . . . . 296

FRONTSIM . . . . . . . . . . 161

FSSOLVE . . . . . . . . . . . 162

FSWEAKW . . . . . . . . . . 163

GGADJUST . . . . . . . . . . . 164

GAS . . . . . . . . . . . . . . . 165

GasCondensate . . . . . . . 312Dissolved . . . . 279, 307Dry . . . . . . . . . 274, 312Saturation . . . . . . . . 320

Wet . . . . . . . . . . . . . 276

Gas-OilContact . . . . . . . . . . 146Ratio

Limit . . . . . . . . 98, 170, 414Solution . . . . . . . . . . . . .122

Gas-Water Contact . . . . . . 146

GCONINJE . . . . . . . . . . . 166

GCONPROD. . . . . . . . . . 168

GECON . . . . . . . . . . . . . 170

GEOFLOFS . . . . . . . . . . 172

GeometryCorner Point. . . . . . . 449

GOCADGRI . . . . . . . . . . 178

GOCADOUT . . . . . . . . . 179

GRAVITY. . . . . . . . . . . . 180

Gravity, zero . . . . . . . . . . 229

Grid BlockActive . . . . . . . . . . . . 78Porosity . . . . . . . . . . 266Size . . . . . . . . . . . . . 128

Grid System . . . . . . . . . . . 27

GRIDFILE . . . . . . . . . . . 181

GroupInjection Control. . . . 166Production Control . . 168

Guide Rate . . . . . . . . . . . 182

GUIDERAT . . . . . . . . . . 182

HHeat capacity. . . . . . . . . . 183

HEATCAP . . . . . . . . . . . 183

History Matching . . . 428, 447

History matchingInjection Wells . . . . . 404

HPV, definition . . . . . . . . 285

HXFIN . . . . . . . . . . . . . . 184

HYFIN . . . . . . . . . . . . . . 185

HZFIN . . . . . . . . . . . . . . 186

IInactive Cell78, 209, 264, 266 to 267


INCLUDE . . . . . . . . . . . 187

INIT . . . . . . . . . . . . . . . 188

Initial pressure . . . . . . . . 270

InjectionRate Control . . . . . . 166Tracer . . . . . . . . . . . 448Well387, 399, 401, 406, 416, 444

History matching . . . . . . 404

Injectivity Index . . . . . . . 423

IORhistory and prediction models284

ISGCR . . . . . . . . . . . . . . 318

JJFUNC. . . . . . . . . . . . . . 189

KKh . . . . . . . . . . . . . . . . . 104

KRG . . . . . . . . . . . . . . . 191

KRGR . . . . . . . . . . . . . . 193

KRO . . . . . . . . . . . . . . . 195

KRORG . . . . . 195, 197, 199

KRORW . . . . 195, 197, 199

KRW . . . . . . . . . . . . . . . 201

KRWR . . . . . . . . . . . . . . 203

LLimit

Economic98, 100, 170, 414, 416Gas-Oil Ratio . . 98, 414Water Cut . 98, 170, 414Water-Gas Ratio. 98, 414

Line Graph Files . . . . . . . . 23

Live Oil . . . . . . . . . . . . . 279

MMAPAXES . . . . . . . . . . . 205

MAPUNITS . . . . . . . . . . 206

Material balance error . . . 163

MatrixCell . . . . . . . . . . . . . 121

MAXSTEP . . . . . . . . . . . 207

MBEMaterial balance error163

METRIC . . . . . . . . . . . . . 208

MINPV . . . . . . . . . . . . . . 209

MINSTEP . . . . . . . . . . . . 210

MISUPPLY . . . . . . . . . . . 211

ModifyArray . . . . . . . . . . . . . 79

Molecular weight . . . . . . . 226

MSGFILE . . . . . . . . . . . . 212

MULTFLT. . . . . . . . . . . . 213

MultiplierTransmissibility . . . . 218

MULTIPLY . . . . . . . . . . . 214

MULTNUM . . . . . . . . . . 216

MULTPV . . . . . . . . . . . . 217

MULTREGT . . . . . . . . . . 218

MULTX . . . . . . . . . . . . . 220

MULTX-. . . . . . . . . . . . . 221

MULTY . . . . . . . . . . . . . 222

MULTY- . . . . . . . . . . . . . 223

MULTZ . . . . . . . . . . . . . 224

MULTZ- . . . . . . . . . . . . . 225

MW . . . . . . . . . . . . . . . . 226

NNet Thickness . . . . . . . . . 231

NEXTSTEP . . . . . . . . . . 227

NNC . . . . . . . . . . . . . . . . 129

NODPPM . . . . . . . . . . . . 228

NOGRAV . . . . . . . . . . . . 229

Non-Neighbor Connection 129

NOSIM . . . . . . . . . . . . . . 230

NTG . . . . . . . . . . . . . . . . 231

NTRNSAVE . . . . . . . . . . 232

Numerical Aquifer . . . . 89, 91

NXFIN . . . . . . . . . . . . . . 233

NYFIN . . . . . . . . . . . . . . 234

NZFIN . . . . . . . . . . . . . . 235

OOIL . . . . . . . . . . . . . . . . 236

OilDead . . . . . . . . . . . 307Live . . . . . . . . . . . . 279Vaporized . . . . .276, 312

OMEGAA . . . . . . . . . . . 237

OMEGAB . . . . . . . . . . . 238

Operation . . . . . . . . . . . . . 79

OPTIONFS . . . . . . . . . . 239

Output Control . . . . .305, 316

Output Control to SLN file 303

Output FilesMultiple/Unified . . . 384

PPARACHOR . . . . . . . . . 246

PBUB . . . . . . . . . . . . . . 247

PBVD . . . . . . . . . . . . . . 248

PCRIT . . . . . . . . . . . . . . 249

PCW . . . . . . . . . . . . . . . 250

PDEW . . . . . . . . . . . . . . 251

PDVD . . . . . . . . . . . . . . 252

PERFORM . . . . . . . . . . 253

PermeabilityRelative201, 203, 321, 327 to 329,

336 to 337, 341, 344, 346

Single . . . . . . . . . . . 123

Permeability tensor . . . . . 164

PERMX . . . . . . . . . . . . . 254

PERMXY . . . . . . . . . . . 255

PERMXZ. . . . . . . . . . . . 255

PERMY . . . . . . . . . . . . . 256

PERMYX . . . . . . . . . . . 255

PERMYZ. . . . . . . . . . . . 255

PERMZ . . . . . . . . . . . . . 257

PERMZX. . . . . . . . . . . . 255

PERMZY. . . . . . . . . . . . 255

PETGRID . . . . . . . . . . . 258

Phase Properties . . . . . . . . 29

PINCH . . . . . . . . . . . . . 259


PINCHNUM . . . . . . . . . .261

PINCHREG . . . . . . . . . . .262

PINCHXY . . . . . . . . . . . .264

PLT Data . . . . . . . . . . . . .441

PNODE . . . . . . . . . . . . . .265

Pore Volume209, 217, 231, 259, 262, 267

PORO . . . . . . . . . . . . . . .266

Porosity . . . . . . . . . . . . . .266

PORV . . . . . . . . . . . . . . .267

PPCWMAX. . . . . . . . . . .268

PRCORR. . . . . . . . . . . . .269

PRESSURE . . . . . . . . . . .270

Pressure. . . . . . . . . . . . . .436boundary . . . . . . . . .265Bubble Point247 to 248, 307Datum Depth . . . . . .146Depth Corrected . . . . 117Dew Point . . . . . . . .252

Pressure boundary condition272 to 273

Pressure, initial. . . . . . . . .270

PRODLIM. . . . . . . . . . . .271

ProductionRate

Control . . . . . . . . . . . . . .168Gas . . . . . . . . . . . . . . . . .170Oil . . . . . . . . . . . . . . . . .170

Well . . . . . 390, 412, 414

Productivity Index . . . . . .423

PSIDE . . . . . . . . . . . . . . .272

PSIDEH . . . . . . . . . . . . .273

PVDG . . . . . . . . . . . . . . .274

PVDO . . . . . . . . . . . . . . .275

PVTG . . . . . . . . . . . . . . .276

PVTNUM . . . . . . . . . . . .278

PVTO . . . . . . . . . . . . . . .279

PVTW. . . . . . . . . . . . . . .281

RRANKING . . . . . . . . . . .282

RANKWELL. . . . . . . . . .284

REFINE . . . . . . . . . . . . .288

Re-Injection Target . . . . . .399

Relative Permeability201, 203, 321,

327 to 329, 336 to 337, 341, 344, 346

Report frequency. . . . . . . 296

Report time. . . . . . . . . . . 377

ReservoirTemperature . . . . . . 309

RESTART . . . . . . . . . . . 290

Restart253, 294, 298, 326, 358

RFT File. . . . . . . . . . . . . 441

ROCK . . . . . . . . . . . . . . 292

RockCompaction . . . . . . . 293

ROCKNUM . . . . . . . . . . 293

RPTALLOC . . . . . . . . . . 294

RPTLINFS . . . . . . . . . . . 296

RPTPRINT . . . . . . . . . . . 297

RPTRST. . . . . . . . . . . . . 298

RPTSCHED . . . . . . . . . . 301

RPTSLN . . . . . . . . . . . . 303

RPTSOL . . . . . . . . . . . . 305

RS . . . . . . . . . . . . . . . . . 306

RSCONSTT . . . . . . . . . . 307

RSVD . . . . . . . . . . . . . . 308

RTEMP . . . . . . . . . . . . . 309

Run title . . . . . . . . . . . . . 360

RUNSUM . . . . . . . . . . . 310

RV . . . . . . . . . . . . . . . . . 311

RVCONSTT . . . . . . . . . . 312

RVVD . . . . . . . . . . . . . . 313

SSATNUM . . . . . . . . . . . . 314

SaturationFunction . . . . . . . . . 320Solver

Tuning options . . . . . . . . 381

Save transmissibilities . . . 232

SCALECRS . . . . . . . . . . 315

Scaled Connate water saturation343

SEPARATE . . . . . . . . . . 316

SGAS . . . . . . . . . . . . . . 317

SGCR . . . . . . . . . . . . . . 318

SGFN . . . . . . . . . . . . . . 319

SGL . . . . . . . . . . . . . . . . 320

SGOF . . . . . . . . . . . . . . . 321

SGU . . . . . . . . . . . . . . . . 323

SIGMA . . . . . . . . . . . . . . 324

SIGMAV. . . . . . . . . . . . . 325

Single Porosity . . . . . . . . 123

Skin . . . . . . . . . . . . . . . . 104

SKIPREST . . . . . . . . . . . 326

SLN fileOutput Control . . . . . 303

SOF2 . . . . . . . . . . . . . . . 327

SOF3 . . . . . . . . . . . . . . . 328

SOGCR . . . . . . . . . . . . . 329

Solution Gas-Oil Ratio122, 306

SOLVSLUG . . . . . . . . . . 330

SOWCR . . . . . . . . . . . . . 332

SSHIFT . . . . . . . . . . . . . 333

START . . . . . . . . . . . . . . 334

STCOND . . . . . . . . . . . . 335

STONE I. . . . . . . . . . . . . 336

STONE II . . . . . . . . . . . . 337

STONE1 . . . . . . . . . . . . . 336

STONE2 . . . . . . . . . . . . . 337

Streamline density . . . . . . 427

SWAT . . . . . . . . . . . . . . . 338

SWATINIT . . . . . . . . . . . 339

SWCR . . . . . . . . . . . . . . 341

SWFN . . . . . . . . . . . . . . 342

SWL. . . . . . . . . . . . . . . . 343

SWOF . . . . . . . . . . . . . . 344

SWU . . . . . . . . . . . . . . . 346

TTABDIMS. . . . . . . . . . . . 347

TAD . . . . . . . . . . . . . . . . 349

TADE . . . . . . . . . . . . . . . 353

TargetRe-Injection . . . . . . . 399Voidage

Replacement . . . . . . 166, 399

TBLK . . . . . . . . . . . . . . . 355

TCRIT . . . . . . . . . . . . . . 356


Temperature . . . . . . . . . . 309water, injected . . . . . 444

Tensor, permeability . . . . 164

Text Files . . . . . . . . . . . . . 21

THICKZ . . . . . . . . . . . . 357

THREADFS . . . . . . . . . . 358

TIADS . . . . . . . . . . . . . . 359

Time Step . . . . . . . . 207, 227

TITLE . . . . . . . . . . . . . . 360

TPAIRS . . . . . . . . . . . . . 361

TPFA . . . . . . . . . . . . . . . 362

TPFV . . . . . . . . . . . . . . . 363

TPVT. . . . . . . . . . . . . . . 364

TRACER . . . . . . . . . . . . 366

Traceradsorption . . . . . . . . 359Concentration . . . . . . 81concentration349, 355, 359, 448Name . . . . . . . . . . . 366pore volume flooded by362

TrackingTracer Concentration81, 355, 448Tracer Name . . . . . . 366

Transmissibilities, save . . 232

Transmissibility103, 218, 220 to 225, 231, 259, 262, 325, 436

TRANX . . . . . . . . . . . . . 367

TRANY . . . . . . . . . . . . . 368

TRANZ . . . . . . . . . . . . . 369

TREFFIC . . . . . . . . . . . . 370

TSCRITFS . . . . . . . . . . . 374

TSTEP . . . . . . . . . . . . . . 377

TUNEFS1D . . . . . . . . . . 378

TUNEFSPR . . . . . . . . . . 380

TUNEFSSA . . . . . . . . . . 381

Tutorials . . . . . . . . . . . . . 455

UUNIFIN . . . . . . . . . . . . . 383

UNIFOUT . . . . . . . . . . . 384

UnitsConstants . . . . . . . . 474

Conventions . . . . . . . 473Conversion factors . . 475

unsmry file . . . . . . . . . . . 296

VVaporized Oil . . . . . 276, 312

Vaporized Oil-Gas Ratio124, 251, 311, 313

VCRIT . . . . . . . . . . . . . . 385

VCRITVIS . . . . . . . . . . . 386

VFPINJ. . . . . . . . . . . . . . 387

VFPPROD . . . . . . . . . . . 390

Voidage Replacement166, 399

Volumetric fluxes . . . . . . . 158

WWATER . . . . . . . . . . . . . 395

Water CutLimit . . . . . 98, 170, 414

Water-GasCapillary Pressure. . . 250Ratio

Limit . . . . . . . . 98, 170, 414

Water-OilCapillary Pressure. . . 250Contact . . . . . . . . . . 146

WCONHIST . . . . . . . . . . 396

WCONINJ . . . . . . . . . . . 399

WCONINJE . . . . . . . . . . 401

WCONINJH . . . . . . . . . . 404

WCONINJP . . . . . . . . . . 406

WCONPAT . . . . . . . . . . . 409

WCONPEND . . . . . . . . . 411

WCONPROD . . . . . . . . . 412

Weak wells . . . . . . . . . . . 163

WECON . . . . . . . . . . . . . 414

WECONINJ . . . . . . . . . . 416

WEFAC . . . . . . . . . . . . . 417

WellBore . . . . . . . . . . . . 104Completion . . . 103, 106

Connection . . . . . . . 421General Specification 424History Matching428, 447History matching . . . 404Injection387, 399, 401, 416, 444Pattern Flood Injection406Periodic Testing. . . . 445Production 390, 412, 414

Well Control. . . . . . . . . . . 30

Well datadimensions . . . . . . . 419

Well list . . . . . . . . . . . . . 434

WELLDIMS . . . . . . . . . 419

WELLSTRE . . . . . . . . . 420

WELOPEN . . . . . . . . . . 421

WELPI . . . . . . . . . . . . . 423

WELSPECL. . . . . . . . . . 424

WELSPECS . . . . . . . . . . 425

WELSTRDN . . . . . . . . . 427

WELTARG . . . . . . . . . . 428

Wet Gas . . . . . . . . . . . . . 276

WFRICTN . . . . . . . . . . . 430

WINJGAS . . . . . . . . . . . 433

WLIST . . . . . . . . . . . . . 434

Workover . . . . . .98, 170, 414

WPAVE . . . . . . . . . . . . . 436

WPAVEDEP . . . . . . . . . 438

WPIMULT. . . . . . . . . . . 439

WRFTPLT . . . . . . . . . . . 441

WSOLVENT . . . . . . . . . 443

WTEMP . . . . . . . . . . . . 444

WTEST . . . . . . . . . . . . . 445

WTMULT . . . . . . . . . . . 447

WTRACER . . . . . . . . . . 448

ZZCORN . . . . . . . . . . . . . 449

ZCRIT . . . . . . . . . . . . . . 450

ZCRITVIS . . . . . . . . . . . 451

Zero gravity . . . . . . . . . . 229

ZMF . . . . . . . . . . . . . . . 452

ZMFVD. . . . . . . . . . . . . 453

frontsim ug

Documents