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8/3/2019 07 Resvr Eng Bw

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These powerpoint files were produced for the Earth History class at the Free University Berlin,Department of Geological Sciences

The copyright for texts, graphical elements, and images lies with C. Heubeck, unless otherwisespecified.

Download, reproduction and redistribution of theses pages in any form is hereby permitted forprivate, personal, non-commercial, and class-related purposes use as long as the source isidentified.

Despite of my efforts, I cannot guarantee the completeness, correctness and actuality of thematerial.

Prof. Christoph HeubeckInstitut fr Geologische WissenschaftenFreieUniversittBerlin

Malteserstr. 74-10012249 BerlinGERMANY

ph: ++49-(0)30-83870695 fax: ++49-(0)[email protected] http://userpage.fu-berlin.de/~cheubeck/

Reservoir Engineering

(light)

Todays Lecture:

Drive Mechanisms Pressure-Transient Analysis Recovery Factor

Subsurface Phases

Links and Literature

Reservoir engineering


2/15

2

Drive Mechanisms

High Porosity Permeability HC saturation

Source of reservoir energy !

Driving force(s) to create apressure differential, causingHC to flow to the wellbore

(natural or artifical)

Drive Mechanisms

What causes hydrocarbons in the reservoir to move to thewellbore ?

Which forces should be supported or pushed back ?

Where and how should secondary recovery strategies beimplemented?

Drive Mechanisms

Gas cap driveSolution gas driveWater drive (Bottom-water, edge-water)

Gravity drainage driveCombination Drive Initial

Conditions

Gas Cap Drive

GasCap

Oil Zone

Danger of depressurizingvolatile phase (gas)

Only where a gas capexists (or where oneforms): RF ~20-45%;possibly assisted bygravity grive

DuringDepletion

GasCap

Oil Zone


3/15

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InitialConditions

DuringDepletion

Solution Gas Drive

Danger of producingvolatile phase (gas) first

Gas comes out of solution as

production causes reservoirpressure decline (cola-cananalogy): Least efficient ofthe drive mechanisms, RF 5-20 % Oil Zone

Bottom Water Drive

Aquifer

Danger of drawing theless viscous phase

(water) to the wellbore(water coning, water

tunneling)

Need aquifer underpressure. Need favorableuniform water advance.RF ~50% but may be ashigh as 85% !

OilZone

Edge Water Drive

Gravity Drainage /Gravity Drive

Present in all reservoirsbut very low productionrates.

Important only near reservoir depletion, in reservoirs with high

structure, and low-viscosity oils


4/15

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Gas Cap

Oil Zone

Gas Cap

OilZone

Combination Drive

Aquifer

Dangers (and possibilities!)from all sides !

0

1

2

3

4

5

0 10 20 30 40 50 60 70

Oil Produced - % of OOIP

Pro

ducingGORmscf/stb

Producing GOR trends by drive mechanism

Solution

gas drive Gravitydrive

Water drive

Gas-to-oil ratio

original oil in place

0

20

40

60

80

100

0 10 20 30 40 50 60 70


ReservoirPressure

(%o

fOriginal)

Reservoir Pressure Trends by drive mechanism

Solution

gas drive

Gravitydrive

Water drive

0

20

40

60

80

100

0 10 20 30 40 50 60 70


WaterCut(%o

fProducedFluid)

Reservoir Water Cut by drive mechanism

Solution gas drive

Gravity drive

Water drive

Gas cap drive


5/15

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Ultimate Recovery Ranges by Drive Mechanism

5-30 ( incremental)GravityGravity Drainage

35-75Aquifer ExpansionWater Drive

20-40Gas Cap and evolvedsolution gas expansion

Gas Cap Drive

5-30Evolved Solution GasExpansion

Solution GasDrive

Recovery (% OOIP)Energy SourceDrive Mechanism

?0

1

2

3

4

5

0 10 20 30 40 50 60 700

1

2

3

4

5

0 10 20 30 40 50 60 70

0

1

2

3

4

5

0 10 20 30 40 50 60 700

1

2

3

4

5

0 10 20 30 40 50 60 70

Gas Cap Expansion Drive Solution Gas Drive

Gravity DriveWater Drive

Black = GOR Blue = water cut Red = pressure

0

1

2

3

4

5

0 10 20 30 40 50 60 700

1

2

3

4

5

0 10 20 30 40 50 60 70

0

1

2

3

4

5

0 10 20 30 40 50 60 700

1

2

3

4

5

0 10 20 30 40 50 60 70

Gas Cap Expansion Drive Solution Gas Drive

Gravity DriveWater Drive

Black = GOR Blue = water cut Red = pressure

Recommendations for perforations

InitialConditions

Gas Cap Drive

GasCap

Oil Zone

As far away as posssible fromthe gas cap in gas capreservoirs

As close to the OWC in agravity drainage

Gravity Drive


6/15

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Recommendations for perforations

As high up as possible inwater-drive reservoirs

Water Drive

Oil Zone

Aquifer

Drive Mechanisms Pressure-Transient Analysis Recovery Factor Subsurface Phases



Pressure-transient analysis of drill-stem tests

DST 1 was performed over

the perforated interval12400 - 12517 MDRTin the Fulmar Fm.

Fig. 62: Halley 30/12b-8 test overview.


Fig. 67: Interpretation of 30/11b-3 DST 1.

110innerradius

Undeterminedouterradius

5280= 1 mile


7/15

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85

28

5280 = 1 mile

Open ?Open ?

Parallel-boundary model for 30/12b-6 DST 1

1550

450

open

4900psi

5800 psi

970 psi

923 psi

882 psi

110inner radius

1000

h(V2) ~ 300, Vol(V2) ~ 3.5e8ft3A(V2)~ 10,000 * 10000ft2

Representedby 4 blocks of2,500 sidelengtheachSpatial Relationto V1 unconstrained

1000

1000

200

V1

85

28ope

n

open

80

160 open

5280= 1 mile

2200

1100

1100

open

30/12b-3Dry hole.Not tested

30/12b-7Dry hole.Not tested

30/11b-1Noreservoir.

Not tested

30/12b-2U-shapedF block

960 psi

Appleton

Alpha

Appleton

Beta

FulmarField

Halley

833 psi

30/12b-4Close Faults (30 deg)

Incomm.with Fulmar ?

30/12b-8In pressure

comm.with 12b-4

30/11b-5poorshows.Not tested

30/12b-6CloseIIfaults.

1080 psi

Appleton / Halley

Fault Compartmentalizationfrom Seismic and Interpretation

ofPTAand RFTData

Fault

Fulmar

AukFault

ClydeField

Major PressureWellGeometrical

e r e e nt t i n1550

450

open

N

30/11b-4DST saw

only 8 -12 MMBOIP

Alpha

Beta

Halley

HalleyGamma

,

Delta

Fault

Outer radius

unknown due to

shorttestduration

Monikie

Zone

30/11b-3Shorttest

gas condensate

Seismic and test data show fieldwide compartmentalization

Drive Mechanisms Pressure-Transient Analysis Recovery Factor

Subsurface Phases




8/15

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Definition Recovery Factor

www.pore-cor.com.

Recovery Factor:

Percentage ofeconomicallyrecoverable reservoirfluid, compared toOriginal Oil in Place(OOIP)

FIELD NAME COUNTRY RSVR AGE RSVR CLSS

HASSI MESSAOUD ALGERIACAMBRIAN FRACTURED TIGHT SANDSTONE

ELMWORTH-WAPITI CANADACRETACEOUS FRACTURED TIGHT SANDSTONE

TURNER VALLEY CANADACARBONIFEROUS FRACTURED MUDDY DOLOMITE

WATERTON CANADADEVONIAN-CARBONIFEROUS FRACTURED MUDDY DOLOMITE

RENQIU CHINAPRECAMBRIAN KARSTIC/FRACTURED MUDDY DOLOMITE

AHWAZ IRAN CRETACEOUS FRACTURED MICROPOROUS LIMESTONE

MANSURI IRAN CRETACEOUS FRACTURED MICROPOROUS LIMESTONE

AIN ZALAH IRAQ CRETACEOUS FRACTURED MUDDY CARBONATE

BAI HASSAN IRAQ TERTIARY FRACTURED ORGANIC BUILDUP

KIRKUK IRAQ TERTIARY FRACTURED/KARSTIC ORGANIC BUILDUP

KARACHAGANAK KAZAKHSTANDEVONIAN-PERMIAN FRACTURED ORGANIC BUILDUP

TENGIZ KAZAKHSTANDEVONIAN-CARBONIFEROUS KARSTIC/FRACTURED ORGANIC BUILDUP

CANTARELL MEXICOCRETACEOUS-TERTIARY FRACTURED FORESLOPE CARBONATE

POZA RICA MEXICOCRETACEOUS FRACTURED FORESLOPE CARBONATE

EKOFISK NORWAYCRETACEOUS-TERTIARY FRACTURED FORESLOPE CHALK

SAFAH OMANCRETACEOUS FRACTURED MICROPOROUS LIMESTONE

IDD EL SHARGI NORTH DOME QATAR CRETACEOUS FRACTURED MICROPOROUS LIMESTONE

VERKHNEVILYUY RUSSIA CAMBRIAN FRACTURED MUDDY DOLOMITE

ABQAIQ SAUDI ARABIA JURASSIC FRACTURED MUDDY CARBONATE

ANSCHUTZ RANCH EAST USA JURASSIC TIGHT SANDSTONE

JONAH USA CRETACEOUS TIGHT SANDSTONE

LOST HILLS USA TERTIARY FRACTURED SILICEOUS SHALE

POINT ARGUELLO USA TERTIARY FRACTURED MICROPOROUS CHERT

WATTENBERG USA CRETACEOUS TIGHT SANDSTONE

YATES USA PERMIAN KARSTIC/FRACTURED CARBONATE SAND

Study of 100fracturedreservoirs

(by C&CReservoirs)

Lithology matrix heterogeneity fracture distribution fluid viscosity drive mechanism wettability

Study of 100 fractured reservoirs ( by C&C Reservoirs)

Reservoir properties

Reservoir managementstrategy

Optimization of production rate EOR technique:

Water flood, steam flood

Enhanced oilrecovery

Fractured

reservoirs

Little matrixporosity andpermeability.Fracturesprovide bothstorage capacityand fluid-flowpathways

Type I

Fractured porous

reservoirs

Low matrixporosity andpermeability.Matrix providessome storagecapacity;fractures providethe fluid-flowpathways

Type II

Microporous

reservoirs

High matrixporosity and lowmatrixpermeability

Type III

Macroporous

reservoirs

High matrixporosity andpermeability.Matrix providesboth storagecapacity andfluid-flowpathways, whilefractures merelyenhancepermeability

Type IV


9/15

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Which one are you goingto buy?

Type I Type II Type III Type IV

Fracturedreservoirs

ave. RF = 21 % ave. RF = 26%

Microporousreservoirs

ave. RF = 24%

Macroporousreservoirs

ave. RF = 34%

Type I Type II Type III Type IV

easily damaged byexcessive production rates.Many perform well underunassisted primary recoverywhen managed properly

dependent uponlithology, wettability,and fracture intensity.The choice of properEOR technique isessential for optimumexploitation

most sensitive todrive mechanism

Fracturedporousreservoirs

Development strategies and reservoir management techniques play crucial roles in maximizingexpected ultimate recoveries for given reservoir/fluid parameters.

Five main fluid type/permeability clastic-reservoir classes, with characteristic ultimate recoverydistributions and controls, are:

(1) heavy oil/tar reservoirs, in which RF is controlled by well spacing/reservoir depth, reservoirconnectivity and the application of tertiary recovery techniques;

(2) low-permeability oil reservoirs, in which RF is controlled by permeability variations, well spacingand application of waterflooding/miscible flooding, fraccing and horizontal drilling;

(3) intermediate-permeability oil reservoirs, in which RF is controlled by fluid viscosity variations,reservoir heterogeneity/architecture and application of waterflooding;

(4) high-permeability oil reservoirs, in which RF is controlled by natural drive strength/type andcontrol of aquifer and gas-cap encroachment; and

(5) gas/condensate reservoirs, in which RF is controlled by permeability variations, aquiferencroachment and condensate drop-out.

Ultimate recovery efficiency in 450 mature clastic fields

Drive Mechanisms Pressure-Transient Analysis Recovery Factor Subsurface Phases




10/15

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Vaporization of a pure substance at constant Pressure

Hg

Hg

Hg

Hg

Liquid

Liquid

Liquid

Gas

Gas

Gas

P1 P1 P1 P1T1 T2=Tv T2=Tv T3

Hg flows out so thatp stays constant

Heating

Vaporization of a pure substance at constant Temperature

Hg

Hg

Hg

Hg

Liquid

Liquid

Liquid

Gas

Gas

Gas

P1 P2=Pv P3T1 T1 T1 T1

P aboveVaporPressure

P2=Pv

Pressure-Volume Diagram of a Pure Substance

T1

T2

T3

T4

T5 = Tc

T6

T7

Dew

PointL

ine

CriticalPoint

Liquid

VaporLiquid+

Vapor

VcSpecific Volume, v

Pressure,p

Bubble

PointLin

e

Pc

Pressure-Temperature Diagram of a Pure Substance

Critical Point

Pc

Liquid

VaporPressure,p Solid

Sublimation

Evaporation

Melting

Condensation ?

Precipitation,Condensation

Freezing

TcTemperature, T


11/15

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Phase properties of the binary ethane ethane system

Reservoir Temperature, deg F

R

eservoirPressure(psia)

200

400

600

800

1000

1200

1400

0 100 200 300 400 500

CriticalPoint

Ethane,CE

CriticalPoint

Heptane,CH

MixtureA

CA

CB

Mixture

B

Dew

Po

intLin

e

Bubble

Poin

tLin

e

Dew

PointLine

Bubb

lePo

intLine

Chemical Composition of Hydrocarbons

Composition of Reservoir Fluids

86,1292,46

73,19

57,6

34,62

8,21

22,57

56,4

0%

20%

40%

60%

80%

100%

DryG

as

WetGa

s

Gasc

onde

nsate

volatile

Oil

Blacko

il

C7+

C6

nC5

iC5

nC4

iC4

C3

C2

C1

N2

CO2

Temperature, deg F

Pressure

,psia

500

1000

1500

2000

2500

3000

3500

4000

4500

5000

0

0 100 200 300 400 500 600 700 800 900 1000 1100 1200-100-200-300

Wet gas

Typicalreservoirtemperatures

92,46

0%

20%

40%

60%

80%

100%

C7+

C6

nC5

iC5

nC4

iC4

C3

C2

C1

N2

CO2

Wetgas

Phase behavior of reservoir hydrocarbon mixtures

Liquid

Gas

Temperature, deg F

Pressure

,psia

500

1000

1500

2000

2500

3000

3500

4000

4500

5000

0

0 100 200 300 400 500 600 700 800 900 1000 1100 1200-100-200-300

GasCondensate

0%

20%

40%

60%

80%

100%

C7+

C6

nC5

iC5

nC4

iC4

C3

C2

C1

N2

CO2

73,19

8,21Typicalreservoirtemperatures

GasCondensate



12/15

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Temperature, deg F

Pressure,psia

500

1000

1500

2000

2500

3000

3500

4000

4500

5000

0

0 100 200 300 400 500 600 700 800 900 1000 1100 1200-100-200-300

0%

20%

40%

60%

80%

100%

C7+

C6

nC5

iC5

nC4

iC4

C3

C2

C1

N2

CO2

57,6

22,57


Volatileoil


Temperature, deg F

Pressure,psia

500

1000

1500

2000

2500

3000

3500

4000

4500

5000

0

0 100 200 300 400 500 600 700 800 900 1000 1100 1200-100-200-300


0%

20%

40%

60%

80%

100%

C7+

C6

nC5

iC5

nC4

iC4

C3

C2

C1

N2

CO2

34,62

56,4

Blackoil


Volatileoil

Temperature, deg F

Pressure

,psia


500

1000

1500

2000

2500

3000

3500

4000

4500

5000

0

0 100 200 300 400 500 600 700 800 900 1000 1100 1200

Blackoil

-100-200-300

GasCondensate

Wet gas


Temperature, deg F

Pressure

,psia

Behavior of fluids during depletion

500

1000

1500

2000

2500

3000

3500

4000

4500

5000

0

0 100 200 300 400 500 600 700 800 900 1000 1100 1200-100-200-300

Bubble

PointL

oci

Dew

PointL

oci


13/15

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Pressure-Temperature Phase Diagram


Rese

rvoirPressure(psia)

500

1000

1500

2000

2500

3000

3500

4000

0 50 100 150 200 250 300 350

Liquid Volume

0%

5%

10%

20%

40%

80%

CriticalPoint

B

Gascondensatereservoir

ReservoirFluid

Bubb

lePo

int

Loci

DewP

ointLoci

Pressure-Temperature Phase Diagram


Rese

rvoirPressure(psia)

500

1000

1500

2000

2500

3000

3500

4000

0 50 100 150 200 250 300 350

CB

A

pat

hofreservoirfluid

Liquid

Volum

e

0%

5%

10%

20%

40%

80%

CriticalPoint

Single-phaseoil reservoir

path ofproduced

fluid

Single-phasegas reservoir

Gascondensatereservoir

ReservoirFluid

ProducedFluid

Bubb

lePo

int

Loci

DewP

ointLoci

Temperature

Pressure

1

C

4

s

3

s

2

s

ReservoirFluid

ProducedFluid


BubbleP

oint

Line

Dew

PointLine

Temperature

Pressure

1

C

4

s

3

s

2

s

ReservoirFluid

ProducedFluid


BubbleP

oint

Line

Dew

PointLine

Hydrate may form from gas andwater upon gas expansion (needantifreeze injection)

Propane injection in oilcan cause dramaticnonlinear viscosityreduction (CO2 isbest)

Gas injection causes re-vaporizationof gas condensate

Gas evolving from oildue to pressure dropduring depletion cancause waxprecipitation

Adding gas (a solvent)to oil (about 40%) cancause asphalteneprecipitation


14/15

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Difficulty and relevance of early reservoirfluid sampling !


Pressure

1

C

4

s

3

s

2

s

Temperature

0

1

2

3

4

5

0 10 20 30 40 50 60 70

pressure

time

asphaltene precipitation

Last word

ReservoirEngineer

ProductionEngineer

PlantEngineer

Geologist GeologistHydrocarbon

Basins


15/15

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Lectura 11 (Summary: Reservesand Resources, unconventional HC)

Lab 10 (PetroMod)

Lectura 10 (Exploration:Hydrocarbon classificationof basins; play types)

Vi

Lectura 8 (Geophysics inexploration and reservoirmanagement)

Lab 9 (Loggingexercise)Lectura 9 (Loggingconcepts and tools;quantitative evaluation oflithology, fluids, andporosity)

Ju

Lectura 7 (Reservoir engineering:Drive mechanisms, phasebehavior,

production problems, scaleformationetc.)

Lab 5 (Boundwater, capillarity

exercise)

Lectura 5 (Reservoirpetrophysics: capillary

pressure, pore-sizedistribution, bound water

etc.)

Mi

Lectura 6 (The reservoir: Lithology,geometry, and facies. Reservoircharacterization and management)

Lab 4 (Porositycalculation)

Lectura 4 (porosidad,permeabilidad)

Ma

Lectura 3 (Geochemistry: Origin ofHC; organicmatter, source rocks,accumulation. The "petroleumkitchen")

Lab 2 (Internetresources)

Lectura 1 / 2 (Introduction;The petroleum system)

Lu

15:15-16:4511:30-13:009:15-10:45

LecturaPracticaLectura

07 resvr eng bw

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