Alkali/Crude Oil Phase Behavior, IFT, and Soap Partitioning Lei Ding Jose Lopez Salinas Maura Puerto Clarence Miller George Hirasaki 2014-04-21 1 Presentation

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Alkali/Crude Oil Phase Behavior, IFT, and Soap Partitioning

Lei DingJose Lopez Salinas

Maura PuertoClarence MillerGeorge Hirasaki

2014-04-21

Presentation for the 18th Rice University Consortium for Processes in Porous Media

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• Introduction• Na2CO3/Crude Oil Phase Behavior• IFT Measurement IFT Measured with Non-equilibrated Samples IFT Measured with Pre-equilibrated Samples • Soap Number Measurement and Soap Partitioning• Conclusion

Contents

IntroductionAlkaline Flooding EOR ProcessTypes of Alkalis:Na2CO3, NaOH, Na2SiO4, Na3PO4, NH4OH, and organic alkalis

Oil DescriptionTAN: 0.88 mgKOH/g (Spiking method)API Gravity (70°F): 27.5°API (0.89 g/cm3)

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Contents

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After equilibrated for 30 days--at room temperature-77°F (25°C)% Na2CO3 [Surfactant-Free Samples] 0 0.5 1.0 1.5 2.0 2.5 3.0 3.5 4.0 4.5 5.0

Phase Behavior at WOR=24

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Phase Behavior at WOR=24After equilibrated for 30 days-at 130°F (54°C)% Na2CO3 [Surfactant-Free Samples] 0 0.5 1.0 1.5 2.0 2.5 3.0 3.5 4.0 4.5 5.0

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Contents

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IFT as a function of Salinity and Temperature (Non-Equilibrated Samples)

Fresh oil and newly prepared alkaline solution are used directly to measure the IFT.IFT values shown are nearly constant values after transient.

0 1 2 3 4 5 61E-03

1E-02

1E-01

1E+00

1E+01

54°C 25°C

Na2CO3 Concentration, %

IFT,

mN

/m

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0 0.5 1 1.5 2 2.5 3 3.51E-03

1E-02

1E-01

1E+00

1E+01

WOR=50WOR=24WOR=9WOR=5WOR=3WOR=1


IFT,

mN

/mIFT as a Function of Salinity and WORs

(Pre-Equilibrated Samples)

IFT values were measured at room temperature after becoming constant using equilibrated samples

Room Temperature

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0 0.5 1 1.5 2 2.5 3 3.51E-03

1E-02

1E-01

1E+00

1E+01

WOR=50WOR=24WOR=9WOR=5WOR=3WOR=1


IFT,

mN

/mIFT as a Function of Salinity and WORs

(Pre-equilibrated Samples)

IFT values were measured at high temperature after becoming constant using equilibrated samples

High Temperature, 130 F

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Contents

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Soap Number MeasurementProcedure

• Soap Extracted by Na2CO3 Solution WOR=3; WOR=5; WOR=9; WOR=24;• Na2CO3 solutions at different concentrations in 20 ml Test Tubes with oil • Rotate, allow to equilibrate, then separate the aqueous phase

• Soap Extracted by Na2CO3 and IPAWOR=3; WOR=5; WOR=24;• Na2CO3 solutions at different concentrations in 30 ml vials;• Rotated and equilibrated as above, add equal volume (as brine) of IPA;• Rotate, allow to equilibrate, then separate the aqueous phaseHigh-pH two-phase titration for soap in aq. phase - BG as indicator, TEGO as titrant, High pH buffer, Chloroform;

( / ) 56.1/aqueous TEGO oilSoap Number mg KOH g slope m C m

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Water Soluble Soap Extracted by Na2CO3 (bars)

Soap Extracted by Na2CO3/IPA (lines)

Note that total acid number = 0.88 mg KOH/g

0.2(0.02) 0.5 (0.05) 1.0 (0.09) 1.5 (0.14) 2.0 (0.19) 2.5 (0.24) 3.0 ( 0.28) 3.5 (0.33) 5.0 (0.47)0

0.1

0.2

0.3

0.4

0.5

0.6

0.7

Water Soluble Soap @WOR=3Water Soluble Soap @WOR=5Water Soluble Soap @WOR=9Water Soluble Soap @WOR=24Soap Extracted by Na2CO3/IPA @WOR=3Soap Extracted by Na2CO3/IPA @WOR=5Soap Extracted by Na2CO3/IPA @WOR=24

Na2CO3 Concentration, % (Molar Concentration)

Soap

Num

ber ,

mg

KOH

/g

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0.2(0.02) 0.5 (0.05) 1.0 (0.09) 1.5 (0.14) 2.0 (0.19) 2.5 (0.24) 3.0 ( 0.28) 3.5 (0.33) 5.0(0.47)0

0.1

0.2

0.3

0.4

0.5

0.6

0.7

Water Soluble Active Soap in Aqueous Phase @WOR=3Water Soluble Active Soap in Aqueous Phase @WOR=5Water Soluble Active Soap in Aqueous Phase @WOR=9Water Soluble Active Soap in Aqueous Phase @WOR=24


Soap

Num

ber,

mg

KOH

/g

Water Soluble Active Soap (WSAS) in Aqueous Phase as a Function of Salinity and WOR

WSAS is that which can partition between oil and aqueous phases, i.e., the difference between water-soluble soap at low and high

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Partition Coefficient of WSAS and IFT

IFTs are measured at room temperature, WOR=3

WOR=3

K=1

0 1 2 3 4 5

0 1 2 3 4 5

1E-02

1E-01

1E+00

1E+01

1E+02

1E-02

1E-01

1E+00

1E+01

1E+02

Soap Partition Coefficient @WOR=3IFT @WOR=3


Soap

Par

tition

Coe

ffici

ent,

K

Salinity, % Na2CO3

IFT,

mN

/m

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0 1 2 3 4 5

0 1 2 3 4 5

1E-02

1E-01

1E+00

1E+01

1E+02

1E-02

1E-01

1E+00

1E+01

1E+02

Soap Partition Coefficient @WOR=9


Soap

Par

tition

Coe

ffici

ent,

K

Salinity, % Na2CO3

IFT,

mN

/m

Partition Coefficient of WSAS and IFT


WOR=9

K=1

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0 10 20 30 40 50 601E-02

1E-01

1E+00

1E+01

1E-03

1E-02

1E-01

1E+00

1E+01

Water Soluble Active Soap Concentration (aqueous), mM/LWater Soluble Active Soap Concentration (oil), mM/LIFT

Water Oil Ratio

Soap

Con

cent

ratio

n, m

Mol

/L

IFT,

mN

/m

WSAS Concentration in Aqueous/Oil Phase as Function of WOR at Optimal Na2CO3 Conc., 1.4 wt% at 77°F

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Contents

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Conclusions• Equilibrium IFT (IFT measured with pre-equilibrated samples)

depends on Na2CO3 concentration, WOR, and temperature. For WOR between 1 and 50 the lowest IFTs occur near 1.4% Na2CO3 at 77°F and near 1.0% Na2CO3 at 130°F.

• At 77°F the water soluble active soap (WSAS) partitioning coefficient is close to unity at 1.4% Na2CO3 for all WOR. However, IFT is lowest when WSAS concentration (at 1.4% Na2CO3) in both aqueous phase and oil phase is greatest, i.e., at WOR=1.

• The lowest IFT measured was 0.001 mN/m for WOR=1 at 130°F, but the ultralow equilibrium IFT region is small.

AcknowledgementThis work was financially supported by Rice University's

Consortium for Processes in Porous Media

Thank you!

Questions?

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Backup

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% Na2CO3 [Surfactant-Free Samples] 0 0.5 1.0 1.5 2.0 2.5 3.0 3.5 4.0 4.5 5.0

After equilibrated for 60 days-at room temperature-77°F (25°C)Phase Behavior at WOR=1

After equilibrated for 60 days using test tubes, emulsions is much less.


After equilibrated for 30 days-at room temperature-77°F (25°C)


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After equilibrated for 30 days-at 130°F (54°C)


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Dynamic IFT behavior of Non-Equilibrated Samples

IFTs are measured at 25 °C and 54°C respectivelyFresh oil and new prepared alkaline solution are used directly to measure the IFT

0 20 40 60 80 100 120 1401E-02

1E-01

1E+00

1E+01

0.1% Na2CO3 at 25°C 0.1% Na2CO3 at 54°C0.2% Na2CO3 at 25°C 0.2% Na2CO3 at 54°C0.5% Na2CO3 at 25°C 0.5% Na2CO3 at 54°C1.0% Na2CO3 at 25°C 1.0% Na2CO3 at 54°C1.4% Na2CO3 at 25°C 1.4% Na2CO3 at 54°C1.6% Na2CO3 at 25°C 1.6% Na2CO3 at 54°C2.0% Na2CO3 at 25°C 2.0% Na2CO3 at 54°C2.5% Na2CO3 at 25°C 2.5% Na2CO3 at 25°C3.0% Na2CO3 at 25°C 3.0% Na2CO3 at 54°C5.0% Na2CO3 at 25°C 5.0% Na2CO3 at 54°C

Time, min

IFT,

mN

/m

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End pointDrop beforeend point

Initial stage 92.5% of the titrant needed for theend point

percentage of completion using the TEGO volume added. [TEGO]=0.002 M0 % 92.5% 99% 100%

High pH Two Phase Titration

José Luis López-Salinas, Ph.D. Dissertation, 2012

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José Luis López-Salinas, Presentation

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José Luis López-Salinas, Presentation

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Sodium Carbonate Consumption by Crushed Berea Sandstone Core as a Function of Concentration

0 20 40 60 80 100 1200

0.2

0.4

0.6

0.8

1

1.2

1.4

Sand Without HCl TreatedSand With HCl Treated

Na2CO3 Concentration, mM/L

Na2

CO3

Cons

umpti

on, m

g/g

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0 50 100 150 200 250 300 350 400 4501E-02

1E-01

1E+00

1E+01

2.0% Na2CO31.8% Na2CO31.6% Na2CO31.4% Na2CO31.2% Na2CO31.0% Na2CO30.8% Na2CO30.5% Na2CO30.2% Na2CO3

Time, min

IFT,

mN

/mEquilibrium IFT as a Function of Salinity and TimeIFT as a function of salinity and aging time at 25°C using equilibrated samples

Samples with a WOR=3 has been equilibrated in test tubes for more than 20 days, see next slide, WOR=3

Under Optimum Region

Over Optimum Region

Optimum Region

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0 50 100 150 200 2501E-02

1E-01

1E+00

1E+01

2.0% Na2CO31.8% Na2CO31.6% Na2CO31.4% Na2CO31.2% Na2CO31.0% Na2CO30.8% Na2CO30.5% Na2CO30.2% Na2CO3

Time, min

IFT,

mN

/mIFT measurement as a Function of Salinity and Time

IFT as a function of salinity and aging time at 54°C using equilibrated samples

Samples with a WOR=3 has been equilibrated in test tubes for more than 20 days, see next slide. After calculation of density WOR=3

Under Optimum Region

Over Optimum Region

Optimum Region

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Comparison of Equilibrium IFT Between With and Without Darker Substance

Samples were equilibrated at room temperature for more than 20 days

0 50 100 150 200 250 3001E-01

1E+00

1E+01

0.5% Na2CO3@WOR=3 with Darker Substance0.5% Na2CO3@WOR=3 without Darker Substance0.8% Na2CO3@WOR=3 with Darker Substance0.8% Na2CO3@WOR=3 without Darker Substance1.0% Na2CO3@WOR=3 with Darker Substance1.0% Na2CO3@WOR=3 without Darker Substance1.0% Na2CO3@WOR=5 with Darker Substance

Time, Min

IFT,

mN

/m

0 20 40 60 80 100 120 140 160 180 2001E-02

1E-01

1E+00

1E+01

1.4% Na2CO3

1.4% Na2CO3-emulsion

1.6% Na2CO3


1.8% Na2CO3


3.0% Na2CO3


Time, min

IFT,

mN

/mComparison of IFT Using Oil and Emulsion

Samples were mixed and then equilibrated at room temperature for more than 20 daysExcess-oil Density has been measured and it is different from the original oil densityEmulsion Density has also been measured

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WOR=5

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0 20 40 60 80 100 120 140 160 1801E-02

1E-01

1E+00

1.4% Na2CO3 Settling for 1 hour1.4% Na2CO3 Settling for 3 hours1.4% Na2CO3 Settling for 1 day1.4% Na2CO3 Settling for 3 days1.4% Na2CO3 Settling for 13 days1.4% Na2CO3 Settling for 20 days1.4% Na2CO3 Settling for 60 days

Time, min

IFT,

mN

/mEquilibrium IFT as a Function of Settling Time

Samples were mixed and then equilibrated at room temperature for different timeExcess-brine Density has been measured and it is different from the original brine density

WOR=51.4% Na2CO3

35

Correlation of IFT with soap Partition Coefficient


WOR=5

K=1

0 1 2 3 4 5

0 1 2 3 4 5

1E-02

1E-01

1E+00

1E+01

1E-02

1E-01

1E+00

1E+01

1E+02

Soap Partition Coefficient @WOR=5IFT @WOR=5


Soap

Par

tition

Coe

ffici

ent,

K

Salinity, % Na2CO3

IFT,

mN

/m

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WOR=24

K=1

0 1 2 3 4 5

0 1 2 3 4 5

1E-02

1E-01

1E+00

1E+01

1E+02

1E-02

1E-01

1E+00

1E+01

1E+02

Soap Partition Coefficient @WOR=24


Soap

Par

tition

Coe

ffici

ent,

K

Salinity, % Na2CO3

IFT,

mN

/m

37


The amount of active soap is regarded as the soap extracted by IPA

K=1

0 1 2 3 4 5

0 1 2 3 4 5

1E-02

1E-01

1E+00

1E+01

1E-02

1E-01

1E+00

1E+01

1E+02

Soap Partition Coefficient @WOR=3Soap Partition Coefficient @WOR=5Soap Partition Coefficient @WOR=9Soap Partition Coefficient @WOR=24IFT @WOR=24IFT @WOR=3IFT @WOR=5IFT @WOR=9


Soap

Par

tition

Coe

ffici

ent,

K

Salinity, % Na2CO3

IFT,

mN

/m

38


The amount of overall active soap is regarded as the WSAS obtained at WOR=24

K=1

0 1 2 3 4 5

0 1 2 3 4 5

1E-02

1E-01

1E+00

1E+01

1E+02

1E-02

1E-01

1E+00

1E+01

1E+02

Soap Partition Coefficient @WOR=3IFT @WOR=3Soap Partition Coefficient @WOR=5IFT @WOR=5Soap Partition Coefficient @WOR=9IFT @WOR=9Soap Partition Coefficient @WOR=24IFT @WOR=24

Salinity, % Na2CO3

Soap

Par

tition

Coe

ffici

ent

Salinity, % Na2CO3

IFT,

mN

/m

TAN, Soap Extracted by IPA, Water Soluble Soap, Water Soluble Active Soap

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0.2(0.02) 0.5 (0.05) 1.0 (0.09) 1.5 (0.14) 2.0 (0.19) 2.5 (0.24) 3.0 ( 0.28) 3.5 (0.33) 5.0(0.47)0

0.1

0.2

0.3

0.4

0.5

0.6

0.7

0.8

0.9

1

water soluble active soap number @WOR=3 water soluble active soap number @WOR=5water soluble active soap number @WOR=9 water soluble active soap number @WOR=24Soap Extracted by IPA @ WOR=3 Soap Extracted by IPA @WOR=5Soap Extracted by IPA @WOR=24 Water Soluble Soap @WOR=3Water Soluble Soap @WOR=5 Water Soluble Soap @WOR=9Water Soluble Soap @WOR=24 Acid Number


Soap

Num

ber,

mg

KOH

/g

TAN=0.88

Soap Extracted by IPA

Water Soluble Soap

Water Soluble Active Soap

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Correlation of IFT with Soap Concentration

The amount of active soap is regarded as the difference of water soluble soap between that at low salinity and high salinity

0 1 2 3 4 51E-03

1E-02

1E-01

1E+00

1E+01

1E-02

1E-01

1E+00

1E+01Water Soluble Soap Concentration @WOR=3Water Soluble Active Soap Concentration @WOR=3IFT @WOR=3

Salinity, % Na2CO3

Soap

Con

cent

ratio

n, m

M/L

IFT,

mN

/m

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Correlation of IFT with Soap Concentration

The amount of active soap is regarded as the difference of water soluble soap between that at low salinity and high salinity

0 1 2 3 4 51E-03

1E-02

1E-01

1E+00

1E+01

1E-02

1E-01

1E+00

1E+01Water Soluble Soap Concentration @WOR=5Water Soluble Active Soap concentration @wor=5IFT @WOR=5

Salinity, % Na2CO3

Soap

Con

cent

ratio

n, m

M/L

IFT,

mN

/m

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Inversion Point with N-octane 1% overall surfactant blend (S13D/S2=4:1)Different Types of Electrolytes

Inversion Molarity and Na Molarity were obtained from phase behavior test while Figures of Na Activity was calculated by Phreeqc Brine Software using pitzer database (for high salinity)

NaCl NaOH Na2CO3 Na2SO40

0.1

0.2

0.3

0.4

0.5

0.6

0.26 0.25

0.160.185

0.26 0.25

0.320000000000001

0.37

0.19 0.180.2

0.22

0.26 0.25

0.48

0.555

Inversion MolarityInversion Na+ MolarityInversion Na+ ActivityIonic Strength

Types of Electrolytes

Mol

ar C

once

ntra

tion,

mol

/L

Documents

Alkali/Crude Oil Phase Behavior, IFT, and Soap Partitioning Lei Ding Jose Lopez Salinas Maura Puerto Clarence Miller George Hirasaki 2014-04-21 1 Presentation