CO2 Demand Estimates for Major Oil Fields in Wyoming Basins

Shaochang Wo, EORI, University of Wyoming

EORI Joint Producers Meeting, June 26, 2007

Powder River Basin

Greater Green River Basin

Bighorn Basin

Wind River BasinOverthrust

Belt

Hanna Basin

Laramie Basin

Jackson Hole

Denver Basin

Shirley Basin

Wyoming Oil & Gas Fields

Wyoming Oil Producing Fields

By the end of 2006, 7024 million barrels of oil (MMBO) have been produced from 1237 oil producing fieldsTop 400 fields with cumulative production of one MMBO or moreTop 400 fields have produced 6865 MMBO, account for 97.7% of the total produced oilOnly top 400 fields were evaluated in this study

Outline

Screening of Wyoming reservoirs suitable for CO2 EORCO2 flood performance in Lost Soldier Tensleep reservoirDimensionless curves of WAG (CO2-water) flood and gravity stable CO2 floodEstimations of initial and total CO2 demand based on hydrocarbon pore volume (HCPV)

Screening Criteria for CO2 Miscible Flood

Sandstone or carbonate reservoirOil gravity > 22 oAPIReservoir depth > 2,500 ftOil viscosity < 10 cp, at reservoir conditionGood waterflood response, usually requires porosity > 7% and permeability > 10mdReservoir cum. oil production > 1 MMBO

CO2 Minimum Miscibility Pressure (MMP) and Formation Fracture Pressure

CO2 MMP and Fracture Pressure in Permian Basin Reservoirs (edited from Heller and Taber, SPE15001)

0

1000

2000

3000

4000

5000

6000

7000

8000

9000

10000

11000

0 1 2 3 4 5 6 7 8 9 10 11 12

Formation Depth, thousand ft

Pre

ssur

e, p

si

MMP (40o API)Frac

ture Pres

sure

Salt Creek

Monell Unit of Patrick Draw

Wyoming Fields with Active CO2 Flood Projects

Lost Soldier

Wertz

Other Possible Candidates for Miscible or Immiscible CO2 Flood

For sandstone or carbonate reservoirIf 13 oAPI < Oil gravity < 22 oAPIIf 1,800 ft < reservoir depth < 2,500 ftIf oil viscosity > 10 cp, at reservoir conditionReservoir cum. oil production > 1 MMBO

Lost Soldier Tensleep: Oil Recovery by Water & CO2 Floods

0

50,000

100,000

150,000

200,000

250,000

300,000

350,000

400,000

450,000

0 20 40 60 80 100 120 140 160 180 200

Cumulative Oil Production, million BO

Mon

thly

Oil

Prod

uctio

n R

ate,

BO

/mon

th

OOIP: 240 MMBO (Brokmeyer, SPE 35191)Recovery by Water FL: 108.7 MMBORecovery by Water & CO2 FL: 134.3 MMBOIncremental Oil by CO2 FL: 25.6 MMBO

CO2 FloodInfillWaterflood

Peripheral Waterflood

Primary

Water FL Rec.: 45.3% OOIPWater & CO2 FL Rec.: 56% OOIPIncremental Oil: 10.7% OOIP

Peripheral water flood only Recovery = 87.7 MMBO 36.5% OOIP

Lost Soldier Tensleep: Cummulative CO2 Injection and Production (by Oct. 2004)

0

100

200

300

400

500

600

700

800

900

1000

1/24/1941 10/3/1954 6/11/1968 2/18/1982 10/28/1995 7/6/2009 3/15/2023

Cum

mul

ativ

e O

il Pr

oduc

tion,

mill

ion

bbl (

MM

BO

)

0

50

100

150

200

250

300

350

400

450

500

Cum

mul

ativ

e G

as o

r CO

2, b

illio

n cu

bic

feet

(BC

F)

Cum. Oil Production

Cum. CO2 Injection

Cum. Gas Prod. (including CO2)

Cum. CO2 Injected: 432 BCF

Cum. CO2 Produced: 310 BCF (estimated)

Net CO2 Needed: 122 BCF (estimated)

Start of CO2 injection in Jan. 1989Cum. incremental oil: 19 MMBO, by Oct. 2004CO2 remained in reservoir: 122 BCFRatio of injected CO2/incremental oil: 22.7 Mcf/BORatio of purchased/injected CO2: 0.282Ratio of net CO2 purchased/incremental oil: 6.4 Mcf/BO

Dimensionless Curves from Lost Soldier Tensleep WAG Flood

0

0.2

0.4

0.6

0.8

1

1.2

1.4

1.6

0 0.5 1 1.5 2 2.5Cumulative WAG Injection, HCPV

Cum

ulat

ive

Inje

ctio

n or

Pro

duct

ion,

HC

PV

Oil ProducedWater ProducedCO2 ProducedCO2 InjectedWater Injected

1 HCPV = OOIP*Bo

Dimensionless Curves of Incremental Oil by WAG Flood

-0.02

0.00

0.02

0.04

0.06

0.08

0.10

0.12

0.14

0.16

0.18

0.00 0.50 1.00 1.50 2.00 2.50 3.00 3.50

Cumulative WAG (CO2 + Water) Injection, HCPV

Cum

ulat

ive

Incr

emen

tal O

il, H

CPV

San Andres Formation, West Texas

Lost Soldier Tensleep

Gravity Stable CO2 Injection

Reservoirs with large dip anglesReservoirs with high concentrations of vertical fracturesTop-down continuous CO2 injectionHigher oil recovery (> 70% of OOIP)Larger volume of CO2 injectionBest for projects designed for CO2 EOR and CO2 storage

Gravity Stable CO2 Flood in Muddy Sandstone Reservoir (calculation based on Wood & Lake' model, SPE 100021)

0

10

20

30

40

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60

70

0 10 20 30 40 50

Initial Saturation of Remaining Oil, %

Oil

Rec

over

y fr

om R

emai

ning

Oil,

%

0

0.1

0.2

0.3

0.4

0.5

0.6

0.7

Pore

Vol

ume

of S

eque

sted

CO

2

Oil RecoveryCO2 Storage

Calculated Case:After 1.2 PV of CO2 injectedReservoir dipping 15 degrees

CO2 Flood (WAG) Injectivity

Good: 10-15% HCPV per yearTypical: 5-10% HCPV per yearMay not be economically viable if injectivity < 4% HCPV per year

Lost Soldier Tensleep: CO2 / Water Injection Ratio

0.0001

0.001

0.01

0.1

1

10

1/1/1988 12/31/1992 12/31/1997 12/31/2002 12/31/2007

Mon

thly

CO

2 / W

ater

Inje

ctio

n R

atio

In surface unit: MCF (CO2) / BW (water)

In reservoir unit: rb (CO2) / rb (water)

Estimating Total CO2 Demand for A ReservoirWith assumptions of 1:1 WAG at reservoir condition; 2.5 HCPV of total WAG injection; 70% of injected CO2 being produced and re-injected

22

3.025.1)( CO

o

BOOIPBMCFDemandCOTotal ×××

=

current recovery current recovery current recovery30% of OOIP 38% of OOIP 45% of OOIP

Basin Field Formation Total CO2, BCF Total CO2, BCF Total CO2, BCFPRB HARTZOG DRAW SHANNON 916 723 611PRB HILIGHT MUDDY 406 321 271PRB LANCE CREEK LEO 371 293 247BHB OREGON BASIN EMBAR 1037 819 691BHB ELK BASIN MADISON 849 670 566BHB ELK BASIN EMBAR-TENSLEEP 658 520 439BHB BYRON TENSLEEP 399 315 266BHB GARLAND MADISON 373 294 248WRB STEAMBOAT BUTTE TENSLEEP 358 283 239WRB BEAVER CREEK MADISON 192 151 128WRB BIG SAND DRAW TENSLEEP 190 150 127GGRB ARCH ALMOND 276 218 184GGRB BRADY WEBER 253 199 168GGRB BRADY NUGGET 200 158 133

Hanna Basin

Laramie Basin

Denver Basin

Shirley Basin

For Miscible CO2 Flood

For Possible Miscible and Immiscible CO2 Flood

OverthrustBelt

Powder River Basin

(Excluding Salt Creek)

291 Reservoirs

4.4~6.6 TCF(168 Res.)

0.8~1.3 TCF(123 Res.)

Wind River Basin52 Reservoirs

1.2~1.9 TCF(28 Res.)

0.1~0.2 TCF(24 Res.)

Greater Green River Basin

(Excluding Lost Soldier & Wertz)

60 Reservoirs

0.8~1.2 TCF(23 Res.)

0.4~0.6 TCF(37 Res.)

Bighorn Basin109 Reservoirs

3.3~4.9 TCF(52 Res.)

1.8~2.7 TCF(57 Res.)

Estimating Initial CO2 Demand for A ReservoirWith assumptions of 1:1 WAG at reservoir condition; injection rate at 10% HCPV per year

22 3652

1.0)/( CO

o

BOOIPBdayMcfRateInjectionCO××××

=

Powder River Basin: Est. Initial CO2 Demand by Reservoirs(Assuming Cum. Oil Prodution as 38% of OOIP)

0.1

1

10

100

1000

1 18 35 52 69 86 103 120 137 154 171 188 205 222 239 256 273 290

Reservoir ID Ranked by Initial CO2 Demand

CO

2 In

ject

ion

Rat

e, m

illio

n cf

/d

Hartzog Draw - Shannon: 264 MMCF/DHilight - Muddy: 117 MMCF/DLance Creek - Leo: 107 MMCF/D

Bighorn Basin: Est. Initial CO2 Demand by Reservoirs(Assuming Cum. Oil Prodution as 38% of OOIP)

0.1

1

10

100

1000

1 8 15 22 29 36 43 50 57 64 71 78 85 92 99 106

Reservoir ID Ranked by Initial CO2 Demand

CO

2 In

ject

ion

Rat

e, m

illio

n cf

/d

Oregon Basin - Embar: 299 MMCF/DElk Basin - Madison: 244 MMCF/DElk Basin - Embar-Tensleep: 190 MMCF/DByron - Tensleep: 115 MMCF/DGarland - Madison: 107 MMCF/D

Wind River Basin: Est. Initial CO2 Demand by Reservoirs(Assuming Cum. Oil Prodution as 38% of OOIP)

1

10

100

1000

1 4 7 10 13 16 19 22 25 28 31 34 37 40 43 46 49 52

Reservoir ID Ranked by Initial CO2 Demand

CO

2 In

ject

ion

Rat

e, m

illio

n cf

/d

Steamboat Butte - Tensleep: 103 MMCF/DBeaver Creek - Madison: 55 MMCF/DBig Sand Draw - Tensleep: 54 MMCF/D

Greater Green River Basin: Est. Initial CO2 Demand by Reservoirs(Assuming Cum. Oil Prodution as 38% of OOIP)

1

10

100

1000

1 4 7 10 13 16 19 22 25 28 31 34 37 40 43 46 49 52 55 58

Reservoir ID Ranked by Initial CO2 Demand

CO

2 In

ject

ion

Rat

e, m

illio

n cf

/d

Arch - Almond: 79 MMCF/DBrady - Weber: 73 MMCF/DBrady - Nugget: 57 MMCF/D

Thanks to

Rick Marvel and Robert Meyer, Wyoming Oil & Gas Commission, for providing field and reservoir production dataKera Presenkowski, student of UW Chemical and Petroleum Engineering Department, for editing the dataWyoming State Geological Survey for providing map files