r Faber Sept 2010 ASP Flooding Lab and Swct Results

8/6/2019 r Faber Sept 2010 ASP Flooding Lab and Swct Results

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2/19

Fields for ASP single well tracer tests

Field A Field B Field C

Oil viscosity (mPa.s) 100 9 2

Total acid number (mgKOH/g oil)

0.77 0.08 0.04

Permeability (mD) 1000+ ~ 600

200 - 1000

~ 100

10

200

Make-up water salinity(TDS mg/l))

4795 10860 Fresh water,

< 1000

Temperature (oC) 46 54 83 (downhole)

During SWCT

(cooling): 70Mineralogy (% clays ~adsorption / consumption)

~ 570% Kaolinite

~ 8.580% Kaolinite

~ 1060% Kaolinite

20% Illite20% Chlorite


3/19

Design of ASP formulation for SWCT and learnings fromSWCT

Phase behaviour studies to establish optimum salinity Flow experiments in Bentheim/Berea sandstone to determine

Activity of ASP formulation Mobility requirements

Flow experiments in reservoir core material to determine influence ofmineralogy on Surfactant retention Caustic consumption Oil recovery efficiency

Single well chemical tracer tests (SWCT) to determine Handling of chemicals Preparation of ASP and polymer solutions on a larger scale Injectivity ASP formulation effectiveness in reducing the remaining oil saturation afterwater flooding


4/19

Surfactant formulation design for Field A

Phase behaviour studies at University of Texas identified suitable surfactantformulation, based on two of Shell Chemicals ENORDETTM surfactants

Solubilisation ratio = 10 ift = 3 x 10-3 mN/m0

5

10

15

20

25

30

0 10000 20000 30000 40000 50000 60000 70000 80000

Electrolyte Concentration,ppm Na2CO3

Solubilization

Ratio,c

c/cc

Oil

Water

Minas Crude ( filt)

Temp = 46 C

After 58 days

Sodium Carbonate scan

0

5

10

15

20

25

30

0 10000 20000 30000 40000 50000 60000 70000 80000

Electrolyte Concentration,ppm Na2CO3

Solubilization

Ratio,c

c/cc

Oil

Water

Crude A

Temp = 46 C

After 58 days

Sodium Carbonate scan

0.3% ENORDET surfactants, 1% co-solvent

oil/water ratio = 1:1

Phase behaviour at 1% surfactantconcentration


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6/19

Single Well Tracer Theory

Figure 5

EtOH (Product) and EtAc (Cover) Tracers

Hypothetical 1-Layer Test Result

0

100

200

300

400

500

600

0 100 200 300 400 500 600 700 800 900 1000

Produced Volume (barrels)

ConcentrationEtOH(ppm)

0

200

400

600

800

1000

1200

1400

1600

1800

2000

ConcentrationEtAc(ppm)

EtOH

Example Data

EtAc

Example Data

Injection:

Ester (30 m3) + Push water (120 m3).Ester partially partitions in oil.

Shut-in: 2 days. Ester partially hydrolysesto ethanol. Ethanol in water phase.

Back production:Ethanol travels faster than ester.

Result:Ethanol and ester return asseparate peaks.Peak distance is used tocalculate Sor.


7/19


8/19

Field A SWCT operation

Polymer slicing unit

3 x 32 m3 tanks for preparing chemical EOR fluids

Chemical storage


9/19

Field A - Tracer test response after water and ASP flooding

EtOH (Product) and NPA (Cover) Tracers

Best-Fit 3-Layer Model (CFSIM)

0

100

200

300

400

500

600

700

800

900

1000

0 1 00 20 0 3 00 4 00 50 0 6 00 7 00 8 00 9 00 1 00 0 11 00 1 20 0 13 00 1 40 0 150 0 160 0 17 00 1 80 0 19 00


Conc

entrationEtOH(ppm

0

100

200

300

400

500

600

ConcentrationNPA(ppm



0

100

200

300

400

500

600

700

800

900

1000

1100

0 100 200 300 400 500 600 700 800 900 1000 1100 1200 1300 1400 1500 1600


ConcentrationEtOH(p

pm

0

100

200

300

400

500

600

700

800

900

ConcentrationNPA(p

pm

Best-Fit 2-Layer Model

Sor = 0.01

Best-Fit 3-Layer

Model

Sor = 0.25

IPA tracer in the ASP fluidcontained ethanol and thisaffected the tracer profile

Sor after water flooding

Sor after ASP flooding

CTI performed tracer test and historymatching of the tracer response


10/19

Fields for ASP single well tracer tests

Field A Field B Field C

Oil viscosity (mPa.s) 100 9 2

Total acid number (mgKOH/g oil)

0.77 0.08 0.04

Permeability (mD) 1000+ ~ 600

200 - 1000

~ 100

10 200

Make-up water salinity(TDS mg/l))

4795 10860 Fresh water,

< 1000

Temperature (oC) 46 54 83 (downhole)

During SWCT(cooling): 70

Mineralogy (% clays ~adsorption /consumption)

~ 5

70%Kaolinite

~ 8.5

80% Kaolinite

~ 10

60% Kaolinite

20% Illite

20% Chlorite


11/19

Surfactant formulation design for Field BPhase behaviour with surfactant formulation: 0.3% ENORDET surfactants (twocomponents), 1% co-solvent

Flow experiments in Bentheim sandstoneASP solution/polymer drive 20 mPa.s 60% recovery

ASP solution/polymer drive 30 mPa.s 92% recovery

0.0

0.1

0.2

0.3

0.4

0.5

0.6

0.7

0.8

0.9

1.0

0.0 0.5 1.0 1.5 2.0 2.5 3.0

Injected fluid volume (PV)

Oilrecovery(fractionSor

),C/Co

&

u/uo

Viscosity produced polymer/viscosity injected polymer

Oil production (fraction Sor)

C/Co surfactant

C/Co Na2CO3

0.0

0.1

0.2

0.3

0.4

0.5

0.6

0.7

0.8

0.9

1.0

0.0 0.5 1.0 1.5 2.0 2.5 3.0

Injected fluid volume (PV)

Oilrecovery(fractionSor

),C/Co

&u/uo

Viscosity produced polymer/viscosity injected polymer

Oil production (fraction Sor)

C/C0 surfactant

C/C0 Na2CO3


12/19

Surfactant formulation design for Field B

Injection side

Production side

Injection side Production side

Injection side

Production side

Injection side Production side

Improved mobility

20 mPa.s at 6 s-1 30 mPa.s at 6 s-1


13/19

Field B - Tracer test response after water and ASP flooding



0

200

400

600

800

1000

1200

1400

1600

0 200 400 600 800 1000 1200 1400 1600 1800 2000 2200 2400 2600 2800 3000 3200 3400 3600 3800


C

oncentrationEtOH(ppm

0

100

200

300

400

500

600

700

800

900

1000

C

oncentrationNPA(ppm

Best-Fit 3-Layer

Model

Sor = 0.20



0

200

400

600

800

1000

0 200 400 600 800 1000 1200 1400 1600 1800 2000 2200 2400 2600 2800 3000 3200 3400 3600 3800


ConcentrationEtOH

(ppm

0

100

200

300

400

500

600

700

ConcentrationNPA

(ppm

Best-Fit 3-Layer

Model

Sor = 0.04

Injection schedule ASP flood 320 m3 ASP solutionoverdisplaced with 290 m3 polymerdrive and 640 m3 water 320 m3 tracer injection of whichthe first 64 m3 contained the tracer(ethyl formate) 36 m interval

Sor after water flooding

Sor after ASP flooding


14/19


15/19

Surfactant formulation design for Field CPhase behaviour tests

% KCl: 0.7 0.8 0.9 1.0 1.1 1.2 1.3 1.4 1.5%

Phase behaviour results with Field C crude after 3 days at 70C.WOR = 70/30, KCl salt was added to increase salinity.

ASP formulation0.7% ENORDETsurfactants (two

components)

1.0% SBA

1.0% Na2CO3

1500 ppm Flopaam 3230S

Optimum


16/19

Surfactant formulation design for Field CCore flow tests (Berea)

0%

10%

20%

30%

40%

50%

60%

70%

80%

90%

100%

0.0 0.5 1.0 1.5 2.0 2.5 3.0

Pore Volumes Produced

%

OilorSurfactant

start ofemulsion

Surfactant

Oil cut

Cumulative oil

ASP core flow tests with Field C crude in Berea core. 1 PV ASPinjected. Temperature = 70oCObservations

95% of remaining oilrecovered

Relative early oilbreakthrough

Most surfactant in waterphase (under-optimum)


17/19

Field C Tracer test response after water and ASP flooding

0

50

100

150

200

250

0 20 40 60 80 100 120 140Produced Volume (m3)

ConcentrationEtOH(ppm)

0

100

200

300

400

500

600

700

800

ConcentrationNPA

(ppm)

Layer 2 accepted 18% of the

tracer-carrying fluid.

Best-Fit 3-Layer

Model: Sor = 0.23

Layer 3 accepted 60% of

the tracer-carrying fluid.

NPA tracerEtOH

Layer 1 accepted

22% of the tracer-

carrying fluid.

Total tracer volume injected: 200 m3. Total ASP volume: 70 m3(equivalent to 0.35 PV in core flow test)Complex tracer responsedue to crossflow duringshut-in.Tracer response modeledwith 3 layers (solid lines)

Before ASP injection: remaining oil = 23 %

After ASP injection: remaining oil = 2%


18/19

Conclusions/further plans

Single well tracer tests showed that the ASP formulations were successful

in reducing the oil saturation to very low values Moving to pattern pilot tests in Field A and C

Objectives:Evaluation effectiveness ASP formulation(s), e.g. surfactant

retention/propagation and caustic consumptionFast oil recovery response

Evaluation of scaling and emulsion problems

When technical and economical issues are satisfactory resolved thenfurther upscaling


19/19

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r Faber Sept 2010 ASP Flooding Lab and Swct Results