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Primary funding is provided by

The SPE Foundation through member donations and a contribution from Offshore Europe

The Society is grateful to those companies that allow their professionals to serve as lecturers

Additional support provided by AIME

Society of Petroleum Engineers Distinguished Lecturer Programwww.spe.org/dl 1

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Society of Petroleum Engineers Distinguished Lecturer Programwww.spe.org/dl

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Improved Oil & Gas Recovery byPolymer Technology: EOR, Water

Shutoff and Sand Control

Alain ZaitounPoweltec, France

Outline

1. EOR Challenges

2. Polymer Flooding

General aspectsField case in heavy oil reservoir

3. Water Shut-Off

Fundamentals of WSO by RPMs

WSO gas well field case

4. Sand Control

Principle of sand control by polymers

Sand control in gas storage wells

5. Conclusions

4

EOR Challenges

• Peak oil occurring soon, oil slow decline expected

• EOR enables increase in Recovery Factor

• Teams mobilized in Major Oil companies

to implement EOR

• Chemical EOR attractive, major focus on polymers

• Low capital cost, low risk, waterflood improvement

5

Malaysia Scenario

• Increasing domesticconsumption

• Forecasted decline from 2007• Net crude importer by ~2010 ?

6

EOR by Polymers

Polymer Flood improves Mobility Control, thus reservoir sweep efficiency

Water flooding Polymer flooding

7

Polymer Flood:

Heavy-Oil Application (Canada)

8

Pelican Lake heavy oil field

• High-permeability sand reservoir

• Thin continuous pay layer (4 m thick)

• Heavy oil – 14°°°° API – 2000 cP

• Shallow, low temperature, fresh water

• Horizontal well primary production

• Low recovery factor (around 5%)

• RF expected to jump to 25% with polymer flood

9

10

Pelican Lake Polymer Flood Pilot

200 m

1400 m

11

Oil rate in Central Producer 00-15-PROMax Injection & Production Rates 150 m3/d

0

5

10

15

20

25

30

35

40

45

1/1/97 1/1/01 1/1/05 1/1/09 1/1/13 1/1/17

Date

Oil r

ate

(m

3/d

)

Water injection

1000 ppm (12 months) then water

1000 ppm (9m) 500 ppm (6m) water

1000 ppm (6m) 500 ppm (12m) water

1000 ppm (3m) 500 ppm (18m) water

1000 ppm (3m) water

Simulation of Polymer Injection Scenarios

12

13

Main outcomes of Polymer Flood pilot

• Polymer Flood has potential in heavy-oil reservoir

• In combination with Horizontal Wells

• Integrated Lab & Simulation studies help designing pilot

• Polymer injectivity is an essential issue

• First pilot results very positive, field extension

implemented by operator (270 injection wells in 2009)

14

Water Shutoff

15

Water Shutoff by Polymer/Gels

• Two strategies: (1) Sealing gels and (2) RPM

• Sealing gels block a water producing interval

• Sealing gels compete with cements or packers

• Relative Permeability Modifiers are weak polymer/gels

• Usually “bullhead” injected into the whole open interval =

cost effective

• Maintain oil/gas permeability while reducing strongly water

permeability

16

Principle of WSO by RPM Polymers

W

Oil Oil

Water

Oil Oil

Water Water Water

WaterOil

Oil

Water

Low k

High K

Two-layer model

Swollen orweakly

X-linked polymer

17

Modification of Relative Permeabilityby Polymer Adsorption

((SorSor))

((SwiSwi))

Adsorbed polymer or microgels

before polymer

after polymer

RRF=10

Principle of RPM treatments

18

Example of successfull WSO treatmentPelican Lake Horizontal Well 11-15A (Canada)

100

500

1000

juil-

85

avr-

88ju

in-8

8

oct-8

8

avr-

89ju

in-8

9

oct-8

9

avr-

90ju

in-9

0

oct-9

0

avr-

91ju

in-9

1

0 %

10 %

50 %

100 %Water

Oil

Water Cut

Year 1 Year 2 Year 3 Year 4

Mo

nth

lyP

rod

uc

tio

n (

m3)

Treatment

0

19

Successful WSO treatment in horizontal well (Canada)

0

1000

2000

3000

4000

5000

6000

7000

0 1000 2000 3000 4000 5000 6000

Cumulated Water Production (m3)

Sandcleaning

Incrementaloil

RPM treatment

Cu

mu

late

dO

ilP

rod

ucti

on

(m

3)

20

New Microgel Technology

dH ≈≈≈≈ 0.3 µµµµm

Small microgelMicrogel A Microgel B

Linear chain

Linear polymer

SMG are calibrated microgels larger and more stable than

conventional polymers

dH ≈≈≈≈ 2.0 µµµµm

21

Several Microgel products proposed today

• “Brightwater” (Popping microgel)

• “Colloidal Dispersion Gels” (CDG)

• “SMG” (Small calibrated microgels)

• “PPG” (Preformed Particle Gels to plug thief zones)

• More used for Conformance Injection well treatments

22

Example of integrated study:

Water Shutoff in a

Gas storage well

Cerville (GDF)

(SPE 106042)

23

Grès à Voltzia

Restriction de perméabilitéAquifère

VA36

Model construction

Well

Reservoir

Low k

Aquifer

24

Simulation forecasts

252001_2002 2002_2003 2003_2004 2004_2005 2005_2006

Effect of Microgel WSO treatment on gas wellDrop in water production

Wa

ter

Ga

s R

atio

Wa

ter

Ga

s R

atio

Microgel Treatment

26

000E+00

05E+06

10E+06

15E+06

20E+06

25E+06

2001-

2002

2002

-200

3

2003-

2004

2004

-200

5

2005

-200

6

well #0

well #1

well #2

well #3

well #4

well #5

Increase in Gas Production rate

2001/02 2002/03 2003/04 2004/05 2005/06

microgel treatment

Wells

Effect of Microgel WSO treatment on gas well

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Sand Control by Polymers

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Principle of action:

Stabilization of rock cement by "coating" with adsorbed

polymer/microgel layer

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Chemical sand consolidation

• Two types of products; (1) Oil-based, (2) Water based

• Oil-based product: resins and organo-silanes

• Resins form hard solid compounds

• Formulations have to re-establish oil/gas permeability

• Water-based polymers are environmentally friendly

• Lower consistency than resins, deeper penetration

• Low costs compared to sand control completions

30

Advantages of water-based RPM polymer products

• Treatment has little impact on oil or gas permeability

• Thus, can be injected into existing completion with no

risk of well plugging

• Deeper penetration possible than with resins or cement,

also much thicker intervals

• Environmentally friendly

water based RPM products

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Sand monitoring device

MicrogelMicrogel treatmenttreatment: : effecteffect on on sandsand productionproduction

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Effect of Microgel Treatment on Sand Production

Sand production Sand production beforebefore treatmenttreatment

Sand production Sand production afterafter treatmenttreatment

Qgas

san

d(u

.a.)

Qgas

san

d(u

.a.)

Sand impacts at wellhead

33

Conclusions

• Polymer Technology has great potential

• Easier and cheaper than other IOR methods

• Both EOR (reservoir) & WSO/Sand Control

(near-wellbore) applications

• New products available (microgels)

• Environmentally friendly (water based)

34

Conclusions (II)

• Broadening field of applications: Sand Control &

EOR in Heavy Oil fields

• New products in WSO and Conformance, more

stable than conventional polymers (microgels)

• Lab/Simulations integrated studies improve

process control & success rate