1

International Joint Study on CO2-EOR- Study on Applicability of CO2-EOR to Rang Dong Field,

offshore Vietnam -

Sunao Takagi, Komei Okatsu

IEA Collaborative Project on Enhanced Oil Recovery30thAnnual Workshop and Symposium

21-23, September, 2009, Australia

2Objectives

To study the CO2 EOR applicability to the offshore oil field in Vietnam through an international joint study between Japan and Vietnam

Laboratory Study Slimtube Test

Interfacial Tension Swelling

Coreflood

Simulation Study Geological Model Upscale

History Match EOS Model

Optimized CO2 EOR

CO2 Source Study Site Survey

Facility Modification Cost Estimation

International Joint Study

3Outline

Reservoir Description and Model

Laboratory Study

Compositional Model Study

CO2 Source Selection

Conclusions

4Reservoir Description and Model

Offshore Vietnam, Water Depth 50-60 meters

　 Production from 1998, Cumulative Production >150MMbbls

　 Reservoir : Fractured Basement and Lower Miocene Sand

Water Injection for both Reservoirs

Production Depletion PhasePressure DepletionHigh GORHigh Water Cut

Field Overview

5Reservoir Description and Model

Depth / Thickness ： 2,100 m / 50 mThin Layered SandPorosity : 25% averagePermeability : md ~ 1,000 mdHeterogeneity

　 Light Oil, API 38 deg, Viscosity<1cp

Cumulative Production >70 MMbbls Reservoir Pressure Depletion <PbAreal Difference

High P, High WC AreaLow P, High GOR Area

Wells : 24 Production Wells (1km well spacing)2 Injection wells

7 km

12 km

Reservoir Overview (Lower Miocene)

6Reservoir Description and Model

Eastern Region

North West Region

Reservoir Pressure Depletion

Maintained PressureHigh Water Cut

Depleted PressureHigh GOR

Production History

Water Drive

7Reservoir Description and Modelφ -K Correlation by FUD Classification

y = 2161.3x3.1071

R2 = 0.8767

y = 329.87x2.9848

R2 = 0.5911

y = 12192x3.2247

R2 = 0.9613

y = 84092x3.4919

R2 = 0.8614

y = 77252x2.1323

R2 = 0.5157

0.01

0.1

1

10

100

1000

10000

0 0.05 0.1 0.15 0.2 0.25 0.3 0.35φ (fraction)

K (m

d)

FUD<500 500<FUD<2500 2500<FUD<10100 10100<FUD<100000100000<FUD (500<FUD<2500)累乗 (FUD<500)累乗 (2500<FUD<10100)累乗

(10100<FUD<100000)累乗 (100000<FUD)累乗

Porosity - Permeability

Core – Log Correlation

Facies K

PHIEDepositional

Environment

Continental

Lagoon

Upper Shoreface

Lower Shoreface

Distal

Continental

Lagoon

Upper Shoreface

Lower Shoreface

Distal

Geological Model

8Reservoir Description and Model

Old Model New Model

Simulation Model and History Match

　 Simulation Model Grid X : Y : Z = 97 : 116 : 40

History Matching

Old Model New Model

9Laboratory Study

D ruc k P ressure ps ig

P ressureTransducer

Tem pera tu re -con tro lled E nvironm ent

In jec tionG as

C y linder

P acked Tub ing

M ercuryIn jec tionfromcontro lledd isp lacem entpum p

F E

G

DC

B

A

Back-PressureRegulator

OilSeparators

2 5 m l2 5 m l

2-Way F lowSelection Valve

GasM eter

Injection Pore Volume: 1.2 PV

Measurement point: 5 points

Packing media: Glass beads

Length: 12.192 m

Internal Diameter 4.6 mm

Porosity: 0.3748

Pore volume: 80.25 cc

Permeability: 9 Darcy

MMP by Slimtube test

70

75

80

85

90

95

100

2000 2500 3000 3500 4000 4500 5000

Pressure (psi)

Rec

over

y by

Slim

tube

test

(%)

Slimtube test (Core Labo.)

MMP: 2,950psi by Slimtube test

Slimtube Test

10

0

10

20

30

40

50

60

70

80

90

100

2000 2500 3000 3500 4000 4500 5000

Pressure (psi)R

ecov

ery

by S

limtu

be te

st(%

)

0

1

2

3

4

5

6

7

8

9

10

IFT

(dy

ne/c

m)

Slimtube test (Core Labo.) IFT measurement (JOGMEC)

0

10

20

30

40

50

60

70

80

90

100

2000 2500 3000 3500 4000 4500 5000

Pressure (psi)R

ecov

ery

by S

limtu

be te

st(%

)

0

1

2

3

4

5

6

7

8

9

10

IFT

(dy

ne/c

m)

Slimtube test (Core Labo.) IFT measurement (JOGMEC)

2 experiments indicatedgood consistent MCM-MMP

: 2,950psi

Laboratory Study

• IFT is calculated by vapor and liquid phase density and contact angle.

• At the point of IFT zero, liquid pendant drops and solves into vapor phase.

IFT =0

Site cell: 15ccPressure: 2,200 psi～4200psiMeasurement point: 17 pointsTemperature: 196 degFInitial volume ratio L:V = 1:1Needle diameter approximate 1.3 mm

This method was introduced by SPE 59338

Experimental Conditions

P = 2,200 psi 4,200 psi3,600 psi2,800 psi2,500 psi

Interfacial Tension

11Laboratory Study

Coreflood Test

Separator

Gas MeterPump

Core Holder

BPR

CO2OilWater

Separator

Gas MeterPump

Core Holder

BPR

CO2OilWater

0%

10%

20%

30%

40%

50%

60%

70%

80%

90%

100%

0.00 0.50 1.00 1.50 2.00 2.50 3.00 3.50 4.00 4.50 5.00 5.50

Gas Injection PV

Reco

very

Fac

tor

& W

ater

Cut

0

1,000

2,000

3,000

4,000

5,000

6,000

7,000

8,000

9,000

10,000

Gas

Oil

Ratio

(cc/

cc)

Recovery (Water) Recovery (Sales Gas1+LPG10%) Recovery (CO2)Water Cut (Water) GOR (Sales Gas1+LPG10%) GOR (CO2)

Water

HC Gas

CO2

InjectantRecovery (%)

@ 1.2 PVRecovery (%)

@ endBreakthrough

(PV)Water 41.2 42.4 0.23

Sales Gas1+LPG10% 63.9 72.7 0.41CO2 (Secondary) 83.8 93.1 0.44

12Compositional Model Study

EOS Model

70.0

72.0

74.0

76.0

78.0

80.0

82.0

84.0

86.0

88.0

90.0

92.0

94.0

96.0

98.0

100.0

2000 2100 2200 2300 2400 2500 2600 2700 2800 2900 3000 3100 3200 3300 3400 3500

Pressure (psig)

Oil

Rec

over

y at

1.2

PV In

j. (%

OO

IP)

MeasuredE300 (Coats Kr)GEM (Coats Kr)

Components in Pseudo-Components in Original System Final System

CO2 CO2N2C1C2C3IC4NC4IC5NC5C6

C7-C14C15-C22C23-C30

C31+

Operation

C7+ Splitting

Lumping N2-C1

Lumping C2-C3

Lumping IC4-C6

PVT MatchingPVT Matching

SlimtubeMatching

Pseudoization

13Compositional Model Study

INJ-3

C-02I

C-09P

C-08P

C-06P

INJ-2

INJ1A

INJ1B

INJ1C

N-08I

INJ1D(N-08P)

N-06

N-11

E-01P

E-12P

E-07PN-09P

N-17P

E-02PE-14PN-14P

N-10P

E-11P

E-13P

E-03P

E-04P

C-05P

E-06P

Loc-2Loc-1

Injector Locations

Initial

History End

Prediction End

Simulation Results

Peripheral > DispersedWAG > Continuous

14Compositional Model Study

Simulation Results

0

5

10

15

20

25

30

35

40

0 50 100 150 200 250

Gross CO2 Injected (MMMSCF)

Oil

Incr

emen

tag

ains

t W

ater

flood

(M

MST

B)

0

2

4

6

8

10

12

14

16

CO

2 Util

izat

ion

Fact

orag

ains

t W

ater

flood

(MSC

F/ST

B)

Oil Increment against Waterflood

Gross CO2 Utilization Factor against Waterflood

Base Case

Oil

Incr

emen

t

1998

2000

2002

2004

2006

2008

2010

2012

2014

2016

2018

2020

2022

2024

2026

CO2 EOR

Water Injection

Natural Depletion

Expected Increments by CO2 EOR

CO2 Injection: 1.0 Million Ton /YearAdditional Recovery by CO2 EOR: 8.1%

4.4% by Water

15CO2 Source Selection

CO2 Sources

CO2 Rich Gas Field1.0 Million Ton/Year520 Km from Target Field1.0 Billion $ (incl. Rang Dong Mod.)

Fertilizer Plant0.4 Million Ton/Year135 Km from Target Field700 Million $ (incl. Rang Dong Mod.)

16Conclusions

Environmental friendly project (CCS oriented) Suitable reservoir fluid for CO2-EOR

Preferable MMP (2,950 psi)High microscopic sweep efficiency (about 90%)Unlikely asphaltene damage around miscible pressure

Successful EOS model to match to the experimental data Gross CO2 utilization factor : 5.5 MSCF/STB Peripheral CO2 WAG injection selected Costly Project (Distant CO2 source) Further Study

(1) Cost reduction / optimization study(2) Further laboratory and simulation studies on enriched hydrocarbon gas injection case(3) Pilot test design for both CO2 injection and hydrocarbon gas injection cases

17

Thank You!!Arigato!!

Xin Cam On !!