Heavy Oil Developmentin Bohai Oilfield

China National Offshore Oil Corp. (CNOOC) Ltd. Tianjin Branch

Sept. 2009

Outline

Heavy Oil Reserves Distribution in Bohai OilfieldsDevelopment Techniques for Heavy Oil in Bohai OilfieldsOther Development Technology for Heavy OilThe Trend of Heavy Oil Development

Brief Introduction for Tianjin BranchBrief Introduction for Tianjin Branch

Shenzhen BranchShenzhen Branch

Zhanjiang BranchZhanjiang Branch

Tianjin BranchTianjin Branch

Shanghai BranchShanghai Branch

CNOOC Ltd. -Tianjin is a Hong Kong-listed CNOOC's subsidiary company, which is in charge of oil and gas E & P in Bohai Sea.

In Bohai Oilfields at present, there are 10,693 MMBOE (1.7 billion m3) developed reserves, and 62 production platforms, 4 terminals, and 6 FPSOs.

Total mining area：

42,973 km2

In which：

Self-operated exploration area accounting for 75.6%

Joint-venture exploration area accounting for 21.3%

Exploitation area accounting for 3.1%

Mining Blocks in Mining Blocks in BohaiBohai SeaSea

Anadarko

图1.1.5 渤海原油密度

中质14.3%

重质75.1%

轻质10.6%

图1.1.5 渤海原油密度

中质14.3%

重质75.1%

轻质10.6%

图1.1.6 渤海原油粘度

稠 油60.0%

稀 油

40.0%

图1.1.6 渤海原油粘度

稠 油60.0%

稀 油

40.0%

Crude Oil Density in Bohai Crude Oil Viscosity in Bohai

By the end of 2008, the heavy oil is the majority in Bohai, and the heavy oil taking account of 75%.

Heavy Oil Reserves DistributionHeavy Oil Reserves Distribution

原油密度（g/m3） 地层原油粘度（mPa.s）

轻质 中质 重质 超重 稠 油 稀 油

＜0.87 ≥0.87～＜0.92 ≥0.92～＜1.0 ≥1.0 ≥50 ＜50

Crude Density Formation Oil Viscosity

Light oil

Medium Heavy Extra-heavy Viscous Thin

Medium oil

Heavy oil Viscous oil

Thin oil

Light

Heavy oil is mainly distributed in Liaoxi Low Uplift, Shijiutuo Uplift, Shaleitian Uplift, Huanghekou Low Uplift, mainly in members of Dongying, Minghuazhen and Guantao formations.

Main heavy oil fields are: SZ36-1, CB, LD, JZ9-3, QHD32-6, NB35-2, PL19-3, BZ25-1S, JX1-1, etc.

Heavy Oil Reserves DistributionHeavy Oil Reserves Distribution

复县

新金

金县

兴城

锦西

秦皇岛

绥中

昌黎

唐山

塘沽

100km.14 " 输气管线

CB

JZ21-1

NW

MNWCP

SW MSW

JAII

AIB

LD32-2

CE

GD

CEPF H

AB

C

DE

F

BZ34-2

JZ9-3

SZ36-1

QHD32-6NB35-2

PL19-3

CB-A/B

CFD11-1/2

BNTerminal

LD10-1

BZ25-1/S

渤海油田重油分布

020040060080010001200140016001800

198519

8719

8919

9119

9319

9519

9719

9920

0120

0320

0520

07

时间

年产量（万方）

中轻油

重油

中轻油22%

重油78%

渤海原油累积产量

The cumulative oil production is 746MMBO (11,860×104m3) in Bohai. And the heavy oil production covers a large part in total production, accounting for 78%.

Heavy Oil Production DistributionHeavy Oil Production Distribution

Heavy

Light&Medium

Light & medium oil

Heavy oil

Oil production in Bohai

Oil production in Bohai

Outline

Heavy Oil Reserves Distribution in Bohai OilfieldsDevelopment Techniques for Heavy Oil in Bohai OilfieldsOther Development Technology for Heavy OilThe Trend of Heavy Oil Development

Nowadays, the development techniques for heavy oil in Bohai are mainly water flooding exploitation, with mainly conventional directional wells and assisted with horizontal wells and highly deviated wells.

Development Techniques for Heavy Oil in Development Techniques for Heavy Oil in BohaiBohai

ERD well

Horizontal multi-lateral well

Horizontal well

New attempts of tertiary oil recovery had been made in some oil fields, such as polymer injection, thermal production.

CB Oilfield is a heavy oil field that was put into production the earliest in Bohai, with surface crude oil density of 0.96 g/cm3 and production history of 24 years.

The edge water is active, so that conventional directional wells had been drilled to develop it with internal spot flooding. Up to now, the oil recovery is nearly 37% with water cut of 87%, and this oilfield has the highest oil recovery ratio in Bohai Bay.

Conventional Development Techniques for Heavy OilConventional Development Techniques for Heavy Oil

埕北油田含水与采出程度关系曲线图

(与常规稠油油田对比）

0

20

40

60

80

100

0 5 10 15 20 25 30 35 40

采出程度(%)

综合含水(%)

埕北油田

孤东油田

孤岛油田

羊三木油田

绥中36-1 I期

绥中36-1 II期

埕东油田

CB

Wat

er c

ut (%

)

Degree of reserve recovery (%)

SZ36-1 is the biggest self-operated oilfield, and is a typical water flooding heavy oil field with surface crude oil density of 0.97 g/cm3, using nine-spot pattern flooding with conventional directional wells. While later 5 horizontal multi-lateral wells had been drilled near the shutdown wells at the edge of this oilfield. Up to now, the recovery is 14% .

Conventional Development Techniques for Heavy OilConventional Development Techniques for Heavy Oil

SZ36-1 OilfieldPhaseⅠ (A, B, J）

1993.9-1997.12 put into production

PhaseⅡ (D,E,F,C,G,H）2000.11-2001.11 put into

production

The effect of profile control in 7 wells in 2004 was obvious, the water cut decreased 5-15% after profile control.

A8

A10

A19

A21 A30

B2B13

B15

J3J4

J6 J14

A1

A2

A3

A4

A7

A9

A12

A13

A14

A15

A20

A22

A25

A26

A27 A31

B1

B3

B4

B5

B6

B7

B8

B9

BB11

J1

J2

J5

J7

J8

J9

J10

J11

J12

J13

J15

J16

-15

-10

-5

0

5

10

15

Water cut difference between Oct. 2004 and July 2004 in profile control block of SZ36-1

Development Techniques for Heavy Oil in Development Techniques for Heavy Oil in BohaiBohai--------Profile ControlProfile Control

F14井开采曲线

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日产液、油 m3

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含水 %

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泵排量

含水

F21井开采曲线

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日产

液、

油 m3

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含水

%

产油量

产液量

泵排量

含水

Layered water injection have been performed in some oilfields in order to restrain interlayer water absorption contradiction and to improve oil recovery ratio.

As shown above, 2 wells of SZ36-1 oilfield have been effected that water cut decreased and oil production went up.

Development Techniques for Heavy Oil in Development Techniques for Heavy Oil in BohaiBohai--------Layered Water InjectionLayered Water Injection

Water cut Water cut

oil

In SZ 36-1 Oilfield, polymer injection began in Oct. 2005. Up to now, 11 wells have been injected polymer, which obviously restrain water cut rising and oil production decreasing.

目前注聚受益油井开采曲线

0

2000

4000

6000

8000

10000

12000

14000

16000

18000

20000

04/1 04/7 05/1 05/7 06/1 06/7 07/1 07/7 08/1 08/7 09/1

日产油、液（m3）

0

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含水（％）

日产液 日产油 含水

4 wells for polymer injection

11 wells for polymer injection

B7 well group polymer injection

expanding in 2008.11 ~ 2016

A7 well group polymer injection expanding in

2005.11 ~ 2016

Development Techniques for Heavy Oil in Development Techniques for Heavy Oil in BohaiBohai--------Polymer InjectionPolymer Injection

Production curves of effected wells after polymer injection

Water cut

oil

Combining polymer injection, profile control and increasing fluid output could achieve better effects.

The figure shows the production curves of SZ36-1-A12 Well. Polymer had been injected in surrounding wells A13 and A19 in April 2009 and May 2009 respectively, and the effect is obvious that the water cut of A12 decreased and oil production increased after big-pump increasing fluid.

Development Techniques for Heavy Oil in Development Techniques for Heavy Oil in BohaiBohai

A12 Production Curves

0

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400

08/8/1

08/9/1

08/10/1

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08/12/1

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09/2/1

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09/4/1

09/5/1

09/6/1

09/7/1

日产

液、

油m

3

40

50

60

70

80

90

100

含水

%

产油量 产液量

泵排量 含水

5.22换大泵

profile control in A13 profile control in A19

Water cut

7

72 7874

0

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120

140

2005年 2006年 2007年 2008年 2009年 2010年 2011年 2012年

年产油

万方

加密后增产

加密调整前

SZ36-1 is the first oilfield adjusted by infilling wells at large scale. 2 new platforms will be added and 36 infill wells will be drilled, which will increase recoverable reserve of 9.1 million cubic meters with recovery ratio increasing 7.7%.

The integrated adjustment during middle and later periods is the key to improve recovery ratio for heavy oil development.

Development Techniques for Heavy Oil in Development Techniques for Heavy Oil in BohaiBohai--------Integrated adjustmentIntegrated adjustment

B16

B12m

The crude oil in NB 35-2 Oilfield is quite heavy and viscous. This oil field had been put into production in 2005 with conventional water flooding, but it’s hard to displace oil effectively. Weak gel injection was tested in June 2008 in well B17, and obvious effect have been achieved that the water cut decreased and oil production increased.

Water cut decreased 18%，oil production increased 10m3/d.

Water cut decreased 4%，oil production increased 2m3/d.

Development Techniques for Heavy Oil in Development Techniques for Heavy Oil in BohaiBohai--------Weak gel injectionWeak gel injection

Water cut

Water cut

Development Techniques for Heavy Oil in Development Techniques for Heavy Oil in BohaiBohai--------Thermal productionThermal production

B14m 多元热流体吞吐生产曲线

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200

9/1/2008 10/31/2008 12/30/2008 2/28/2009 4/29/2009

时间

日产

油/

液（

m3/d

）

日产油

日产液

The injection temperature in well B14m is 132℃.The average oil production of this well was 35m3/d and hade been increased up to 64m3/d after thermal fluid injected, which is 1.8 times of former.

Formation crude oil viscosity: 666mPa.s

The beginning productivity of South NB35-2 Oilfield using cold recovery is: directional well 18m3/d and horizontal well 35m3/d. Now the production rate of South Oilfield is only 0.3% with quite low oil recovery. So that, multi-component thermal fluid huff and puff had been tested in this area.

South

North

B14m

Outline

Heavy Oil Reserves Distribution in Bohai OilfieldsDevelopment Techniques for Heavy Oil in Bohai OilfieldsOther Development Technology for Heavy OilThe Trend of Heavy Oil Development

人为建立起原油的快速网络通道人为建立起原油的快速网络通道

“DFASC” artificially develops flow channels near well bore:1. “Drilling-fracturing” forms the main channel;2. “Appropriate sand control” forms worm holes and enlarges oil flow

channels by making the fine sand produce from formation.

DrillingDrilling--Fracturing, Appropriate Sand Control (DFASCFracturing, Appropriate Sand Control (DFASC))

“DFASC” technology has been applied in 199 wells of 11 offshore oilfields. Oil production of single well increased from 16-75m3/d to 36-255m3/d. The average single well productivity improved by 2-5 times.

Oilfield Number ofwells

SZ36-1 5

BZ25-1 5

NB35-2 21

LD 14

CB 1

Others 153

Total 199

外径 (in) 重量 (ppf) 钢级 扣型

井眼 6"套管 7 23.0 N-80 BTC筛管 4 1/2 14.6 K55 LTC油管 2 7/8 6.5 J-55 EUE

序号 外径 (in) 内径 (in) 长度 (m) 顶深 (m)

1 11.002 2.9922 变扣（ 3-1/2"EU P×2-7/8"EU P) 2.875 2.4413 2.875 2.441

2.875 2.4414.970 2.312 240.002.875 2.441

5 2.875 2.4412.875 2.4416.110 2.417 600.002.875 2.441

9 2.875 2.44110 2.821 2.31213 2.875 2.441

14 2.875 2.44115 2.875 2.441

3.071 1.8753.9763.9763.9764.4885.906 2.441

17 3.513 2.87518 0.750 N/A19 3.000 3.00020 2.875 2.441

A 6.000 3.250BCD 4＃圆电缆

E 4.500 4.000F 4.500 3.640G 5.000 3.250H 4.500 3.640I 5.000 3.250J 4.500 4.000K 5.000 N/A

2 7/8"EU J55 油管

扶正器

电子压力计托筒（带压力计）

变扣

保护器

变扣

泵头

3/4"抽油杆20根

公司 : CNOOC

描述

油补距

KOP:18.6m

油田：QHD32-6井号 :最大井斜 :

4

4 1/2"短盲管

4 1/2"优质筛管

3.25"密封筒

16

2 7/8"EUE J-55油管

2 7/8"EUE J-55油管

分离器

2 7/8" EU "F" 坐落接头

2 7/8"EUE N-80油管短节

8 7" ESP Packer Assembly

电机

2 7/8"EUE N-80油管短节

电潜泵

2 7/8"EU 6.5# J55 油管

2 7/8"泄油阀

2 7/8"EUE N-80油管短节

2 7/8"EUE N80油管短节

Baker 井下安全阀

油管挂 3 1/2"EUE BXB

2 7/8"EUE J-55油管

3/8"压力计数据电缆

1/4"液压控制管线

备注：采用55、66、77级梯级筛管防底边水

Beta Breaker密封筒

GPV引鞋（带单流阀）

4 1/2"盲管

4 1/2"优质筛管

"SC-1R"封隔器

1

4

8

10

14

16

20

B

D

A

E

E

HG I J K

Gravel Filling in Small Open Horizontal HoleGravel Filling in Small Open Horizontal Hole

Explored a new way for adjusting wells.(QHD32-6)

Gravel Filling in Small Open Horizontal HoleGravel Filling in Small Open Horizontal Hole

采油层

注气层

1 注气油管

5 电泵机组及电缆

6 防返吐单流阀

3原井套管

2 采油油管

7分层封隔器及

插入密封组成

反洗阀

4 特殊 Y 接头

2 活动接头

1 4-1/2”油管

3大通径钢管

4 潜油电泵机组

5 套铣管下接头

6丢手下体

7分流接头

8 定位封隔器

9 2 7/8 ″油管

103.25″插入密封

11 分层封隔器

Production water layer

Injection water layer

Pumping oil and injecting gas in same well had been successfully practiced in well LD10-1-A3 in Nov. 2007, meeting the requirements for gas injection and oil production, which has improved a lot the efficiency of single well.

OneOne--holehole--manymany--using Production Technology in using Production Technology in BohaiBohai

Pumping water and recharging in same well had been successfully practiced in SZ36-1 Oilfield in Sept. 2006. Daily water output 1400m3 and daily water injected 900m3, which has restrained insufficient injection.

Production oil layer

Injectiongas layer

Chemical Viscosity Reducing for Heavy Oil Chemical Viscosity Reducing for Heavy Oil

空白原油流动形态 (粘度为 2980mPa · s)Original crude oil flowing pattern (Viscosity 2980 mPas)

Crude oil flowing pattern after 0.3% BJN-03 added (Viscosity 119 mPas)

After chemical viscosity reducing agent huffed and puffed in NB35-2-B1, the flowing resistance of formation oil reduced near the well bore, forming pressure drop funnel, which has improved the fluid supply capacity of formation, and consequently the dynamic fluid level in well bore rised up.

By the end of Feb, totally 1500 tons of oil had been increased in Well B1. Next, we will analyze and optimize this technique and spread it in Bohai Oilfields for better achievements.

Chemical Viscosity ReducingChemical Viscosity Reducing

777

62119

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564 568

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08年5月2日吞吐降粘作业777

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08年5月2日吞吐降粘作业Visbreaking operation

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5.2-5.6吞吐降粘作

业，12日开井，6月

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业，12日开井，6月

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oil

water

Visbreakingoperation

Outline

Heavy Oil Reserves Distribution in Bohai OilfieldsDevelopment Techniques for Heavy Oil in Bohai OilfieldsOther Development Technology for Heavy OilThe Trend of Heavy Oil Development

☆ Innovation and development for well completion techniques as multi-lateral diversion with appropriate sand control (ASC) and sand control within casing pipe.

☆ Research on reservoir protection for unconsolidated sandstone depleted reservoirs

☆ Research on reservoir formation protection and well-bore stability technology

☆ Research on new technology for offshore heavy oil development

☆ Offshore polymer injection research and thermal recovery test

☆ Research on offshore steam soaking or steam driving

Future Research Direction for Heavy Oil Future Research Direction for Heavy Oil Development in Development in BohaiBohai

Futu

re D

evel

opm

ent D

irect

ion

Futu

re D

evel

opm

ent D

irect

ion

In the future 10 years, the oil production

of Bohai Oilfields will come to a new

stage, and the heavy oil is still the

majority.

Drilling technology and oil production technology should be combined when developing heavy oil, to achieve better development effect. We believe that there is no more difficulties in heavy oil development in the future.

Prospects of Heavy Oil Development in Prospects of Heavy Oil Development in BohaiBohai

Thanks