SURTEK

Chemical Enhanced Oil Recovery

Malcolm J. Pitts Surtek, Inc.

SURTEK

SURTEK

Oil Bank

Waterflood Residual OilA

SP

Poly

mer

Wat

er

Chemical Flood Mechanism

Injection Production

Ultimate Residual Oil

Chemical Flood is Not like a waterfloodChemical Flood effects only reservoir contacted by chemicals

• Fluid is Injected at an Injection Well• Injected Fluid Moves through an Oil Reservoir• Mobilized Oil Produced at a Production Well

SURTEK

o

poVIAD B

VSEEENp •=

Oil Recovery Equation

Capillary Number Mechanism –Pore to PoreDisplacement EfficiencyHow well does the injected fluid move oil?

Mobility Control Mechanism -Volumetric Displacement EfficiencyOil Recovery

Stock Tank Oil Saturation

SURTEK

• application objectives• recover 15 to 30% OOIP as incremental oil• cost of incremental oil is less than $20.00/bbl• rate of return 50% or greater

• two primary mechanisms• a mobility control mechanism • a capillary number mechanism

Chemical Floods

SURTEK

σLP

ForcesSurfaceForcesViscousNca

/Δ==

Capillary Number Mechanism

Improves ED

SURTEK

SURTEK

0.0 0.5 1.0 1.5 2.0 2.5Alkali Concentration (wt%)

1E-3

1E-2

1E-1

1E+0

1E+1

Inte

rfac

ial T

ensi

on (m

N/m

)

Na2CO

3+ Surfactant

NaOH + Surfactant

42 API

22 API

Alkali-Surfactant IFT Reduction

0.0 0.5 1.0 1.5 2.0 2.5Alkali Concentration (wt%)

1E-3

1E-2

1E-1

1E+0

1E+1

Inte

rfac

ial T

ensi

on (m

N/m

)

Na2CO

3

NaOH

42 API

22 API

SURTEK

Interfacial Tension Criteria

interfacial tension reduction alone does not result in good oil recovery

150 oF Interfacial TensionInjected Solution (mN/m)- ASP Solution #1 <0.001 - ASP Solution #2 <0.001- ASP Solution #3 <0.001- ASP Solution #4 0.001

0.0 1.0 2.0 3.0 4.0 5.0Cumulative Produced Fluids (PV)

0

10

20

30

40

50

60

70

Cum

ulat

ive

Oil

Rec

over

y (%

OO

IP)

Primary and Waterflood Chemical Flood

SURTEK

Alkali and Surfactant• alkali

• alters rock wettability• reacts with oil to form surfactants• adjusts pH and salinity• alters rock chemistry, reducing adsorption• acts as a mild biocide• stabilizes polyacrylamide to H2 S catalyzed

oxidative degradation• surfactant

• reduces oil-water interfacial tension• alkali plus surfactant

• synergistic interfacial tension reduction

SURTEK

Alkaline Agents

Increase solution pH > 7

Most common alkalis used in chemical floods are:

• soda ash (Na2 CO3 )

• caustic soda (NaOH)

SURTEK

Surfactant

Surfactant (surface active agent)

C7 – C10

C4 – C5

CH3

H3C

H3C SO-

3 Na+

Hydrophobic

Hydrophillic

AnionicCationicNon-ionicZwitterionic - Amphoteric

SURTEK

oiloil

waterwater

kk

MobilityPhaseDisplacedMobilityPhaseDisplacingM

μμ

//

==

Mobility Control Mechanism

Improves EVI and EA

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Polymers

Macromolecules composed of repetitive units - monomers

Most common CEOR polymers are:

• hydrolyzed polyacrylamide (HPAM)

• xanthan gum (biopolymer)•Most important CEOR property

• changing mobility of injected fluid

• increase viscosity

• reduce effective water permeability

SURTEK

Oil Displacement in 5-spotWaterflood, break through in 1 hour 19 minutes

Polymer flood, break through at 2 hours and 4 minutes, better sweep

SURTEK

Alkali,Surfactant, and Polymer• Capillary Number Mechanism

• alkali• surfactant

• improve oil removal from pores

• Mobility Control Mechanism• polymer

• improve contact efficiency• improve displacement of oil to well

• Combining Mechanisms• synergistic oil recovery

SURTEK

Wilmington Crude Oil

Waterflooded to Sorw = 0.40 Vp

Flooded with 1 pore volume low IFT slug

Flushed with 2 pore volumes of water

Recovered 0.05 pore volume incremental oil

Sof = 0.352 “

dia.

2 foot length©

SURTEK

Capillary Number Mechanism

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Wilmington Crude OilWaterflooded to Sorw = 0.40 Vp

Sof = 0.35

Sof = 0.36

Flooded with 1 pore volume polymer = oil viscosityFlushed with 2 pore volume of water

Recovered 0.04 pore volume incremental oil

©

SURTEK

Mobility Control Mechanism

Capillary Number Mechanism

2 foot length

2 “

dia.

SURTEK

Flooded with 1 pore volume ASP Solution Viscosity of ASP Solution = oil viscosity

Recovered 0.37 pore volume incremental oil

Sof = 0.03

Sof = 0.36

Sof = 0.35

©

SURTEK

Capillary Number Mechanism

Mobility Control Mechanism

Combined Capillary Number and Mobility Control Mechanisms

2 foot length

2 “

dia.

SURTEK

0.0 0.5 1.0 1.5 2.0 2.5 3.0Normalized Cumulative Produced Fluids (PV / PV Waterflood)

0.0

0.5

1.0

1.5

2.0

N

orm

aliz

ed C

umul

ativ

e O

il R

ecov

ery

(%O

OIP

Rec

over

y / %

OO

IP W

ater

flood

)

Alkaline-Surfactant-Polymer FloodWaterflood

Berea

J Sand

Muddy

Sand Type Effect on Recovery

reservoir rock is critical for a successful design

SURTEK

Tanner Field

Mellott Ranch

Cambridge

Timing of Floods• Cambridge

secondary flood• Tanner

waterflood to40% oil cut

• Mellott Ranch35 yearswaterflood to5% oil cut

Alkaline-Surfactant-Polymer Floods

SURTEK

Secondary Alkaline-Surfactant-Polymer Flood Net Pay Isopach

Alkaline- Surfactant- Polymer Flood InjectionWell

Cambridge FieldASP area = 5,684 MBBL PV

Mobility Ratio = 2.2 to 5.8

Permeability = 845 md

Oil API Gravity = 20o

Oil Viscosity = 31 cpAlkaline-Surfactant-Polymer flooding beginning 1993

SPE Res. Eng., Dec. 2000

SURTEK

Cambridge Alkaline-Surfactant-Polymer Flood Production

1989 1993 1997 2001 2005

1,000

10,000

100,000O

il (b

bl/m

onth

)

1

10

100

% O

il C

ut

ActualActualSimulatedOil Cut

Oil Production

HistoryMatchPrimary

ForecastSecondaryASP Flood

Primary

Alkaline-Surfactant-Polymer Flood

SURTEK

Cambridge Federal 23-28

1989

1994

1999

2004

2009

100

1,000

10,000

100,000

Oil

(bbl

/mon

th) -

Wat

er (b

bl/m

onth

)

0.1

1.0

10.0

100.0

% O

il C

ut

Oil Cut

Oil

Water

SURTEK

Cambridge Alkaline-Surfactant-Polymer Flood Recovery Summary

Ultimate Oil Recovery 73.2 %OOIPPrimary and Waterflood 39.8 %OOIP

ASP Incremental Recovery 33.4 %OOIP

Cost per Incremental Barrel 2.95 $/bblcost includes chemicals and plant

SURTEK

Cambridge Comparison Alkaline-Surfactant-Polymer Flood

0.00 0.05 0.10 0.15 0.20 0.25 0.30 0.35 0.40 0.45 0.50Cumulative Oil after Injection Begins

Cumulative Waterflood or ASP Oil (Vp)

1

10

100%

Oil

Cut

Field ComparisonsCamridgeMellott Ranch ASP floodAverage Waterflood

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Alkaline- Surfactant- Polymer Flood InjectionWell

Mid-Waterflood Alkaline-Surfactant-Polymer Flood Net Pay Isopach

SPE 100004

Tanner FieldASP area = 2,528 MBBL PV

Mobility Ratio = 3.2

Permeability = 200 md

Temperature 175oF

Oil API Gravity = 21o

Oil Viscosity = 11 cp

Waterflood beginning November 1997

Alkaline-Surfactant-Polymer flooding beginning March 2000

SURTEK

Tanner, Wyoming Alkaline-Surfactant-Polymer Flood

1991 1993 1995 1997 1999 2001 2003 2005 2007 20091

10

100

% O

il C

ut

1,000

10,000

100,000

Mon

thly

Oil

Prod

uctio

n (b

bls)

Primary

Waterflood

Alkaline-Surfactant-PolymerFlood

Oil Cut

Oil Production

CalculatedContinuedWaterfloodOil Cut

SURTEK

Tanner Alkaline-Surfactant-Polymer Flood Recovery Summary

Ultimate Oil Recovery 65.0 %OOIP

Primary and Waterflood 48.0 %OOIPto 3% oil cut

ASP Incremental Recovery 17.0 %OOIP

Cost per Incremental Barrel $4.49 (estimated)Includes Chemical and Facilities

Primary and Waterflood 31.3 %OOIPto 3/2000 – 40% oil cut

SURTEK

Tanner Alkaline-Surfactant-Polymer Flood Production Compared to Eight Minnelusa Waterfloods

Tanner

0.00 0.05 0.10 0.15 0.20 0.25 0.30 0.35 0.40 0.45 0.50Cumulative Oil Produced After Injection Begins (PV)

1

10

100

% O

il C

ut

Field ComparisonsCamridgeTotal Tanner FieldTanner 24-30Tanner 22-31Tanner Calculated WaterfloodAverage Waterflood

arrows incicate start of ASP for TannerMay 2000

SURTEK

Alkaline- Surfactant- Polymer Flood InjectionWells

Tertiary Alkaline-Surfactant-Polymer Flood Net Pay Isopach

`H

Water Injection Well

Mellott Ranch FieldASP area = 12,200 MBBL PV

Mobility Ratio = 7.6

Permeability = 640 md

Temperature 133oF

Oil API Gravity = 21o

Oil Viscosity = 23 cp

Waterflood beginning December 1965

Alkaline- Surfactant- Polymer flooding beginning August 2000

SURTEK

Mellott Ranch Northeast Sand, Northern Wells 34-02, 41-11, and 11-12H Producing

21-11 and 32-1 Injecting

1961 1966 1971 1976 1981 1986 1991 1996 2001 20061.0

10.0

100.0

% O

il C

ut

1,000

10,000

100,000

Mon

thly

Oil

and

Wat

er P

rodu

ctio

n (b

bls)

Oil CutOilWater Injection

SURTEK

Mellott Ranch Northeast Sand, Northern Wells 34-02, 41-11, and 11-12H Producing

21-11 and 32-1 Injecting

1991 1995 1999 2003 2007 20111.0

10.0

100.0

% O

il C

ut

1,000

10,000

100,000

Mon

thly

Oil

and

Wat

er P

rodu

ctio

n (b

bls)

Oil CutOilWater Injection

ASP Injection August 2000

Polymer DriveJune 2004

WaterMay 2006

SURTEK

Mellott Ranch Northeast Sand Waterflood Comparison Alkaline-Surfactant-Polymer Flood

0.00 0.05 0.10 0.15 0.20 0.25 0.30 0.35 0.40 0.45 0.50Cumulative Oil Produced After Injection Begins (PV)

1

10

100

% O

il C

ut

Field ComparisonsCamridgeMellott Ranch ASP floodAverage Waterflood

SURTEK

Secondary Alkaline-Polymer Flood Net Pay Isopach

Thompson Creek FieldAP area = 26,000 MBBL PV

Mobility Ratio = 13.6

Permeability = 1,400 md

Temperature 88oF

Oil API Gravity = 19o

Oil Viscosity = 300 - 515cp

Waterflood beginning July 2002

Alkaline- Polymer flooding beginning May 2004

SURTEK

10

100

1000

STB

/day

Jul-87 Jul-92 Jul-97 Jul-02 Jul-07 Jul-12 Jul-17 Jul-22

020406080

100

Oil

Cut

%

Thompson Cr. – Wyoming USABegin AP Injection

SURTEK

Thompson Cr. – Wyoming

Additional Recovery

Less Injection

0.0 0.5 1.0 1.5 2.0 2.5Cumulative Injection, PV

0

1,000

2,000

3,000

4,000

5,000

6,000

Cum

ulat

ive

Oil,

MB

BL

Alkaline-Polymer ForecastWaterflood ForecastActual

SURTEK

Alkaline-Polymer FloodEtzikomAP area = 21,500 MBBL PV

Mobility Ratio = 17.2

Permeability = 1000 md

Temperature 86oF

Oil API Gravity = 19o

Oil Viscosity = 100 cp

Waterflood beginning 1971

Alkaline- Polymer flooding beginning December 2000

SURTEK1967 1972 1977 1982 1987 1992 1997 2002 2007 2012

0

10

20

30

% O

il C

ut

0

10,000

20,000

30,000

Mon

thly

Oil

and

Wat

er P

rodu

ctio

n (b

bls)

Field Oil CutField Oil Rate

APDec 2000

Polymer DriveMarch 2003

WaterMay 2005

Chemical Flood oil productionmatches historical maximum rate

Oil CutIncrease2.5 to 17.0%

Oil Rate Increase10,200 bbl/m to29,100 bbl/m

Alkaline-Polymer Flood Etzikom C Pool 22,000,000 bbl Full Field

SURTEKSURTEK1967 1972 1977 1982 1987 1992 1997 2002 2007 2012

0.1

1.0

10.0

100.0

% O

il C

ut

100

1,000

10,000

100,000

Mon

thly

Oil

and

Wat

er P

rodu

ctio

n (b

bls)

Oil CutOilWater Production

Etzikom Alkaline-Polymer FloodWell 03-24 of C Pool

33 years primary and waterflood

7.5 years alkali-polymer flood

SURTEKSURTEK

0 50,000 100,000 150,000 200,000 250,000 300,000Cumulative Oil (bbls)

0.1

1.0

10.0

100.0

% O

il C

ut

100

1,000

10,000

100,000

Mon

thly

Oil

and

Wat

er P

rodu

ctio

n (b

bls)

Oil CutOilWater Production

Etzikom Alkaline-Polymer FloodWell 03-24 of C Pool

33 years primary and waterflood140,000 bbls

7.5 years alkali-polymer flood140,000 bbls additional

SURTEK

Alkaline-Surfactant-Polymer FloodWarnerASP area = 50,000 MBBL PV

Mobility Ratio = 10.9 – 12.4

Permeability = 2100 md

Temperature 95oF

Oil API Gravity = 19o

Oil Viscosity = 58 cp

Polymer Flood beginning 19672 injection wells

Water beginning 1972

Alkaline-Surfactant-Polymer flooding beginning May 2006

SURTEK

1963 1968 1973 1978 1983 1988 1993 1998 2003 2008 2013

0

2

4

6

8

10

% O

il C

ut

0

20,000

40,000

60,000

80,000

100,000

Mon

thly

Oil

Prod

uctio

n (b

bl)

Oil CutOil Rate

ASP InjectionMay 2006

Oil Rate Increasedfrom 9,000 bbl/m to49,600 bbl/m

Oil Cut Increasedfrom 1.7 to 8.4%

Alkaline-Surfactant-Polymer Flood Warner 50,000,000 bbl Full Field

SURTEK

What Makes a Successful Flood?

• reservoir engineering and geology• laboratory evaluation• numerical simulation• facilities design• careful field operations• monitoring flood performance

SURTEK

Thank You!