33rd IEA EOR SymposiumAugust 26th – 30th, 2012

R i S k t h C dRegina, Saskatchewan, Canada

Implementation of CO2-EOR Huff ‘n’ Puff Pilot Test in Oil Fields Offshore of Vietnam

- Advances in CO2-EOR Research –August 29th , 2012

Aiko Nishizaki1, Yusuke Fujita2, Tadao Uchiyama2

Sunao Takagi1, Yoshiaki Ueda2 , Hiroshi Mituishi1

1.Japan Oil, Gas and Metals National Corporation, 2.JX Nippon Oil & Gas Exploration Corporation

A dAgenda1 Introduction1. Introduction

2. Operation Planning and Designp g g

3. Pilot Test Operation

4. Pilot Test Results

5. Conclusions

2

A dAgenda1 Introduction1. Introduction

2. Operation Planning and Designp g g

3. Pilot Test Operation

4. Pilot Test Results

5. Conclusions

3

1 Introduction - objectives1. Introduction - objectivesTo study the CO2 EOR applicability to the offshore oil field in Vietnam through an international joint study between Japan and Vietnam

International Joint Study

Laboratory Study Simulation Study CO2 Source StudySlimtube Test

Interfacial TensionSwelling Test

Coreflood Test

Geological Model UpscaleHistory MatchEOS Model

Optimized CO2 EOR

Site SurveyFacility Modification

Cost EstimationCoreflood Test Optimized CO2 EOR

4

1 Introduction - test field overview1. Introduction - test field overview

= Reservoir Description =

API Oil Gravity : 36 38- API Oil Gravity : 36-38- Pressure (initial) : 3,100 [psi]- Depth : 2,100 [m]- Oil Saturation : over 30 [%]

Hanoi

- Permeability : over 10 [md]

Da Nang

Hue

Rang Dong

H Chi Mi h CitHo Chi Minh City

Test Well

5

100km200km300km

Test Well

About 120km Offshore of Vung Tau

A dAgenda1 Introduction1. Introduction

2. Operation Planning and Designp g g

3. Pilot Test Operation

4. Pilot Test Results

5. Conclusions

6

2 Operation Planning and Design2. Operation Planning and Design

I j t Oil

Three Stage Actions

Inject CO2

Soak ProduceOil,

Water & CO2 • Single Well

• Short Test• Small CO2 Requirement

H ff

Reservoir FluidInteraction

q• Minimum Impact to The Facility

Huff Soak Puff

To Confirm CO2 Injectivity To Confirm Increased Oil ProductionObjectives To Confirm Increased Oil Production To Confirm Some Mechanisms of CO2 EOR

- Volumetric Swelling

Objectives

7

- Viscous Reduction Effects- Change in Oil Property

2 Operation Planning and Design2. Operation Planning and Design

(LM Section of BM producer)(LM Section of BM producer)“Test Well”

(LM Section of BM producer)(LM Section of BM producer)

Lower Miocene

Actual Reservoir Pressure(=2,800psi)Higher than Expected (2,400~2,600psi)

Basement

Low Deviation(24 deg) Actual Oil Saturation(=Avg 31-36% by RST)

(Estimated Oil Saturation before The Test=20-30%)

8

A dAgenda1 Introduction1. Introduction

2. Operation Planning and Designp g g

3. Pilot Test Operation

4. Pilot Test Results

5. Conclusions

9

3 Pilot Test Operation - operation sequence

Perforation of The Target Section

P&A of Lower Reservoir Section

3. Pilot Test Operation - operation sequence

Completion String

C i Sh t i & RST L i #1

Pre CO2 Injection Flow

Perforation of The Target Section

Casing

CO2 Injection

Shut-in & RST Logging #1

Perforation IntervalPost CO2 Injection Flow

Soaking & RST Logging #2

Target Reservoir

MPLT Logging & BHS

Shut-in & RST Logging #3

10

P&A of Target SectionLogging Tool

Total : 18days

A dAgenda1 Introduction1. Introduction

2. Operation Planning and Designp g g

3. Pilot Test Operation

4. Pilot Test Results

5. Conclusions

11

4 Pilot Test Results - CO injection performance4. Pilot Test Results - CO2 injection performance

BHPBHP

Total CO2 Injected Volume = 111 [ton] (=2.1 [MMscf]), MMP = 2,980 [psi]

WHPInjection Rate

12

4 Pilot Test Results - production performance4. Pilot Test Results - production performance Oil Rate GOR BS&W Choke Size CO2 in Gas API 60

Pre Flow Post Flow

80

90

100

2,500

3,000

Gas

[%]

40API

Inje

ctio

n60

702,000

[ /64

"]; C

O2

in

GO

R [s

cf/s

tb] 30

60;

Water Cut Oil RateCO

2 CO2

Concentration

30

40

50

1,000

1,500

%];

Cho

ke S

ize

Oil

Rat

e [b

bl/d

]; 20

API

Concentration

10

20500

Wat

er C

ut [%O 10

GOR

950 bpd -> 1,500 bpd+550 bpd (1.6 times)

13

00

5/23

5/24

5/25

5/26

5/27

5/28

5/29

5/30

5/31

6/01

6/02

Date

0

2

4 Pilot Test Results - production performance4. Pilot Test Results - production performance Oil Rate GOR BS&W Choke Size CO2 in Gas API 60

Pre Flow Post Flow

80

90

100

2,500

3,000

Gas

[%]

40API

Inje

ctio

n60

702,000

[ /64

"]; C

O2

in

GO

R [s

cf/s

tb] 30

60;

Water Cut Oil RateCO

2 CO2

Concentration

30

40

50

1,000

1,500

%];

Cho

ke S

ize

Oil

Rat

e [b

bl/d

]; 20

API

Concentration

10

20500

Wat

er C

ut [%O 10

GOR WC=50-60% ->0%

14

00

5/23

5/24

5/25

5/26

5/27

5/28

5/29

5/30

5/31

6/01

6/02

Date

0

2

4 Pilot Test Results – the logging analysis4. Pilot Test Results – the logging analysis

Perm

ELAN(OH Log in 1997)

#2 RST(After CO2)

#3 RST(After Post-Flow)

#1 RST(Before CO2)

TPHIBefore CO2After CO2Post-Flow

2

3MainlyWater

0 So 10.1Perm

100[md]

0 So 1 0.45 -0.15[m3/m3]

0 So 1

3Zone

Perf

.#2

CO2 High P4

WaterHigh Perm.

4Best CO2 Injected Zone

So reductionby CO2 Inj.

CO2Mid. P

ShaOil bank

5

6WaterMid. Perm.

Shalek

Swept out

5

62nd Best CO2

Perf

.#1

CO2

CO2 Mid. P

Sha

6

78

Water

Mid. Perm.

Shale

6

78

2 Best CO2 Injected Zone

15

CO2 High P9High Perm. 9

4 Pilot Test Results – the fluid analysis4. Pilot Test Results – the fluid analysis

Viscosity & Swelling Test

Oil SamplesOil Fingerprint

6 54.82.2 1.6

3 16.7 4.6 7.9

90%

100% C31+

C23 C30

Oil Composition

Swelling Test

12.4

18.7

8.1

15.1

11.2

6.2

12.0

17.2

11.9

22.7

6.5 6.43.1

40%

50%

60%

70%

80%

90% C23-C30

C15-C22

C7-C14

IC4-C6

C2-C30.0

1.0

2.0

3.0a

bc

d*2

e

f

gP ris/phy (s)

t

u

vx

y

Figure 1B: rada plot showing the correlation of eight(8) N-oils from the RANG DONG Fie ld(15-2-rd)

0.1

50.4

5.2

37.5 27.8

0%

10%

20%

30%

Pre-flow Rec Oil

Post-flow Rec Oil(#2)

Post-flow Rec Oil(#3)

N2-C1

CO2

h

i

jk

lm

no

p*4

q

r

1.111 1.02 1.12 1.3001.414 N21P N06P N17PTest Well Well A Well B

Oil fingerprint analysis shows the same type of oil produced as the other Lower Miocene wells.

Oil composition analysis also indicates there is not much difference with the t ti L Mi il

16

representative Lower Miocene oil. Oil swelling and viscosity reduction test shows the improvement of oil mobility

by CO2 is calculated more than 3 times of the original flowing condition.

4 Pilot Test Results – the simulation analysis4. Pilot Test Results – the simulation analysisSimulation Model

2000

Actual No Injection Case CO2 Injection Case

Production Oil Rate100ft (17grids)

1500 [ft]

80010001200140016001800

ate,

bbl

/d

Inje

ctio

n

Perf. #2100ft

At The End of Soaking

0200400600800

5/25 5/26 5/27 5/28 5/29 5/30 5/31 6/1 6/2 6/3

Oil

Ra

CO

2 I

80ft

Perf. #1

Layer Zone Assumption

Date

8090

100

% n

Water Cut0.0 0.7CO2 Concentration in Oil

y p1 3 Water Zone2 4 Oil Zone3 5 Shale4 6 Water Zone

203040506070

Wat

er C

ut, %

O2

Inje

ctio

n17

5 7 Oil Zone6 8 Shale7 9 Oil Zone

01020

5/25 5/26 5/27 5/28 5/29 5/30 5/31 6/1 6/2 6/3

W

Date

C

4 Pilot Test Results – the simulation analysis4. Pilot Test Results – the simulation analysis

Actual No Injection Case CO2 Injection Case

Production Oil RateThe differential oil rate between

1400160018002000

bbl/d

Actual No Injection Case CO2 Injection Case

tion

No injection and CO2 injectionindicates 214 [bbl] oil increment

by CO2 injection.

400600800

10001200

Oil

Rat

e, b

CO

2 In

ject

0200

5/25 5/26 5/27 5/28 5/29 5/30 5/31 6/1 6/2 6/3Date

Oil Increment

Parameter Unit Simulation Calucluation Result

Injected CO2 Mscf 2,100Oil I t bbl 214

18

Oil Increment bbl 214CO2 Utilization factor Mscf/bbl 9.8

A dAgenda1 Introduction1. Introduction

2. Operation Planning and Designp g g

3. Pilot Test Operation

4. Pilot Test Results

5. Conclusions

19

5 Conclusions5. Conclusions

The first CO2-EOR Huff ‘n’ Puff pilot operation in Vietnam offshore Tfield was successfully achieved. No critical issue about operation including CO2 injection and flow back was identified.

Good and stable CO2 injectivity was confirmed. At the same time, good responses to show CO2-EOR effect were also observed as oil increase, water cut oil saturation reduction, and component/property

G

change.

The pilot test indicated over 200 barrels of oil increase by 111 tons Tof CO2 injection, which is equivalent to around 10 Mscf/bbl of CO2 utilization factor.

20

33rd IEA EOR SymposiumAugust 26th – 30th, 2012

R i S k t h C dRegina, Saskatchewan, Canada

XIN CAM ON !ARIGATO !

THANK YOU !THANK YOU !