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Reservoir Drainage Workflow using three ESRI ArcGIS extensions

Andrew Zolnai

Petroleum GIS Training

September 2007

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Original idea

• Presentation over 10 years ago to model reservoir depletion using stock ARC/INFO tools• invert a reservoir GRID, model the flow in ARC/INFO, and drape

the flow lines on the original GRID

• This exercise will do the same with current ESRI extensions• AAPG Search and Discovery CD-ROM Series #1: The Whittier

Fault Trend

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Spatial Analyst work flow

• Go to:• ArcGIS Desktop Help > Spatial Analyst

> Hydrologic tools

• We will use Hydrologic Tools to:• Formation top as a DEM

• That will provide the elevation data

• Apply Flow Direction and the Flow Accumulation tool

• The direction in which water would flow out of each cell is determined

• Apply a Conditional filter

• All cells with more than 100 cells flowing into them will be part of the stream network

• Order, link and create a stream vector

• These steps will create a shape file defining the stream network system

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Petroleum work flow

• Stream flow modelling is common in ArcGIS• Water flowing down a DEM

• Spatial Analyst extension tools

• Subsurface flow is the reverse• Hydrostatic recharge replaces

gravity

• Formation top replaces topography

• Simply inverse stream flow modelling• Invert the topography.......................

• Run stream flow work flow..............

• Build the flow vector network...........

• Drape it over the original surface

• Tools used• Spatial Analyst extension

• ArcToolbox for the tools

• Model Builder to link all tools

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Model Builder

• ArcToolbox• Open it by clicking the red toolbox icon

• Right-click on ArcToolbox

• Click on New Toolbox

• Select the new toolbox just created

• Right click on it and select New

• Select Model and a window opens

• This is the canvas onto which the various modules will be dragged• Basically it asks for

• an input file

• a function

• an output file

• It provides a means to test and edit the routines iteratively

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Elevation data

• Go to the Model subfolder• Get the raster formation top from

the exercise data set

• Multiply the raster by -1 to invert the elevations• In ArcToolbox, go to Spatial

• Analyst Tools then to Math

• Likewise click, drag and drop Negate tool into the Model Builder

• Double-click on the yellow box & fill in the input and output boxes

• Note: if you have a polygon formation top, rasterise it first• Do the same as above first:

• ArcToolbox Conversion tools To Raster Feature to Raster

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Raster flow analysis

• The formation top is now like regular slope in ArcMap, and Spatial Analyst tools will be used to study the flow

• In ArcToolbox go to Spatial Analyst then Hydrology • Drag Flow Direction onto the Model

Builder canvas

• Use the previous raster as input

• Select an output raster

• Keep the rest as defaults

• Do the same with Flow Accumulation

• Return to Spatial Analyst then Conditional tools• Do the same with Con

• Input 0 and 1 as False and True values

• This thins the output into a network

• Over 100 similar cells form a flow network

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Vector flow analysis

• The conditional tool set a threshold of rasters to create a flow net, which will now be ordered, linked and vaporised into a flow network

• Return to the Hydrology tools in Spatial Analyst on ArcToolbox• Do the same as before with Stream

Order

• Repeat with Stream Link and Stream to Feature

• Use file names indicated below

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Run the model

• Click on the black arrow to run it• The tool being run turns red

in the canvas

• A screen will track its progress and give any errors

• If there are any errors• The boxes will show as clear

• Double-click on them and look for alarm logos

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Subsurface flow model

• What did we do?• Took a formation top and converted it into a raster slope

• Modelled surface water flow as an analog to subsurface petroleum flow

• Used

• Spatial Analyst extension to process rasters

• 3D Analyst extension to display vectors

• Model Builder tool canvas to tie it altogether

• Caveat Emptor• This is a surface flow model adapted to subsurface flow

• Flow will diverge not converge, and create many vertices

• To be further refined with additional surficial factors

• Further resources• Groundwater flow models in Spatial Analyst

• Online help and other industry resources: http://www.esri.com/industrieshttp://support.esri.com/kb http://training.esri.com/campus/library/index.cfm