The Puguang Gas Field in Sichuan Basin of China

-a case study for natural gas development issues

9 Oct 2008

Outline1 An Overview of Puguang Gas Field1. An Overview of Puguang Gas Field

2.Project PlanjFracture prediction of carbonate reservoir

S h l l lf d i iSour nature gas phase, elemental sulfur deposition

prediction and its controlling & prevention techniques

Edge/bottom water utilization and invasion controlling

CO2 capture and storage

Puguang gas field located at the

1 An Overview of Puguang Gas FieldPuguang gas field, located at the

northeast of Sichuan Basin, was

discovered in 2003. It is the largest

carbonate high so r gas field incarbonate high sour gas field in

China. Gas in initial place(GIIP) of

Puguang has reached 300×109m3.

It, desinged raw gas production 12 billion per year, will be put into production in 2009.

Reservoir Characteristics

Reservoir pressure：

55-57MPa

Sour gas content：

H2S15.2%、 CO28.6%

Reservoir depth：Reservoir depth：

4800-5800m

3D model of Puguang gas reservoir

Elevation of water depth: RDGR

普 光 10

RD10100000

GR0 90

普 光 9

VLLD10100000

VGR0 90

P20 1- 2

RDGR

普 光 6

海 拔

Reservoir Characteristics

Elevation of water depth:Two diffirent water-gas

systems. Changxing

5300

5400

5500

5600

101000000 90

5200

5300

5400

101000000 90

4600

4700

4800

101000000 90

4800

4900

5000

5100

101000000 90( m)- 4 2 09

- 4 2 59

- 4 3 09

- 4 3 59

- 4 4 09

- 4 4 59

- 4 5 09飞systems. Changxing

formation :-5230m

5600

5700

5800

5900

5500

5600

5700

5800

4900

5000

5100

5200

5200

5300

5400

- 4 5 59

- 4 6 09

- 4 6 59

- 4 7 09

- 4 7 59

- 4 8 09

- 4 8 59

1+2 段兴

长

Feixianguan formation: -5111m

6000

6100

6200

6300

5900

6000

6100

53005500

- 4 9 09

- 4 9 59

- 5 0 09

- 5 0 59

- 5 1 09

- 5 1 59

- 5 2 09

- 5 2 59

海拔-5111m

海拔-

组兴

Reservoir type:structural- lithologic b t

6400

6500

6200

6300

- 5 3 09

- 5 3 59

- 5 4 09

- 5 4 59

海拔5230m

carbonate sour gas reservoir

NO.P6-P10well reservoir profile

Project Plan(1)Fracture prediction techniques of carbonate reservoirFractures developed largely in Puguang gas field,

which can be recognized by core observation and FMI.

(1)Fracture prediction techniques of carbonate reservoir

The calculated results of fracture Fracture occurrenceFMIFormation

series

formation

倾向：南南西Fei

xian guan

Lower

Trias

Fei xian

Fractures developed

走向：北西西

guanTriassic gua

n

5078 00 5116 00 m

Fractures developed largely in the bottom of Feixianguan formation from FMI interpretation

西

－南东东

Upp

5180.00 – 5220.40 m

5078.00 – 5116.00 m5123.80 – 5148.00 m5156.00 – 5170.00 m

倾角：240

－580

changxing

Upper

permian

ProblemsFracture prediction is difficult in the world ,and which is the challenge in p g

Puguang gas field.

Genetic mechanism of fracture ：relationship among strata formation,

lithology, lithofacies and fracture development is not clear.

Seismic methods of fracture prediction：most of the methods are

lit ti d biqualitative and ambiguous.

Quantitative modeling fracture ：quantitative description of effective

fracture distribution is very difficult.

●Fine description of fractured carbonate outcrop: the rules and mechanisms of fracture developing

Workshops

mechanisms of fracture developing.

●Mechanical simulation of fracture: the mechanism of fracture developing the relationship between fracture developing anddeveloping, the relationship between fracture developing and structure&lithology.

●Identification method of fractures: how to identify natural●Identification method of fractures: how to identify natural effective fractures and induced ones based on FMI, and the accuracy of fracture identification based on conventional well log.

● 3D seismic quantitative fracture prediction: seismic data quality, prediction methods.

● Modeling methods of fracture reservoir.

Plan & Schedule

•Workshops and experts visiting : 2～3

•Expert team: Norway, Canada, United States or

CCOP MC t 3 5CCOP MC experts 3～5

•Venue: ChinaVenue: China

•Time:2009～2010

Project Plan

（2）Sour nature gas phase, elemental sulfur deposition prediction and its controlling & prevention techniques

Problems

It is very difficult to get sour gas phase y g g p

experiment data.Ｈ２Ｓ, a toxic and corrosive

gas usually makes experiment apparatus leakgas , usually makes experiment apparatus leak,

even brings to human being or animals damage.

It has great deviation on elemental sulfur

deposition prediction in complex formation and

multiphase percolation.

General sulfur solvents are poor efficient ,

on the other hand, high efficient sulfur

solvents are not only expensive but alsosolvents are not only expensive but also

unable recycled which always make pollution.

Elemental sulfur deposited in formation far

away from the wellbore or fracture could not

be resolved by any sulfur solventbe resolved by any sulfur solvent.

Workshops•High sour gas phase experiment programs and phase h t i ticharacteristics,•Elemental sulfur saturation experimental test and prediction modelprediction model , •Physical simulation of elemental sulfur deposited in different media,,•Modeling elemental sulfur deposition in different flow media and multiphase, •Developing economic, effective and clean sulfur solvent, ••Measurements to resolve elemental sulfur deposited in deep formation.

Plan & Schedule

•Workshops or experts visiting: 2～3

•E t t C d U it d St t F•Expert team: Canada, United States , France

or CCOP MC experts 2～3

•Venue: China

•Time:2009～2010

Project Plan

（3）Edge/bottom water efficient utilization and invasion controlling

It could enhance the natural gas recovery if edge/bottom water has been actively controlled and used its drive energy. Otherwise it would certainly cause water fast fingering, forming the seal gas

Possible problems that water invasion creates during sour gas

range and creating the gas well flooding.

field development:Pipelines and equipments corrosion rate increased,

Gas well production and gas recovery decreased,

It is difficult to treat produced water, which brings problems to the environmental protectionproblems to the environmental protection.

Workshops

Methods preventing water irregular

coning/movementconing/movement,

Sealed gas second development

techniques,

Water gas well safe production andWater gas well safe production and

corrosion protection ,

Wasted water reinjection and storage.

Plan & Schedule

•Workshops and experts visiting: 2～3

•Expert team: Russian ,United States or CCOP MC

experts 2～3.

•Venue: China

• i 2009 2010•Time:2009～2010

Project Plan

（4）CO2 capture and storage Technical aspect and questions

SINOPEC has attached importance to

p q

CO2 purify and processing. The Puguang

gas field located at mountain land and

many gas pools scattered distributed are y g p

apart from the purification factory.

It ,therefore, has a

long way to go for g y g

economic and

effective sour gas

field development.

But the CO2 capture

and storage projects

were few that made

China petroleumChina petroleum

companies lack the

related experiencerelated experience.

Workshops

Gas pool produced CO2 economic

clean capture and storageProductionProduction

clean capture and storage,

Super critical properties of CO2

InjectionInjection

and the effect to its reinjection,

CO2 corrosion protection and Acid gas slugAcid gas slugO il

arly

ggy

CO2 corrosion protection and

corrosion monitoring.Acid gas Mixing Zone Acid gasAcid gas

Plan & Schedule

•Workshops and experts visiting: 2～3

•Expert team: Norway, Canada, United States or

CCOP MC experts 2～3.

•Venue: China

• i 2009 2011•Time:2009～2011

W l t P fi ld!Welcome to Puguang gas field!