Thermodynamic Characterization of Reservoir Fluids

and Process Analysis

o The thermodynamic characterization of reservoir and

injected fluids allows us to perform rigorous analyses of

the oil recovery processes.

o A continuous program that will reveal important factors

that are still unknown or not well understood and affecting

the efficiency of oil recovery.

o A synthesis of theoretical and experimental components.

Adidharma/Towler/Radosz

Department of Chemical and Petroleum Engineering, University of Wyoming

Achievement

Theoretical component:

o Developed a unified advanced model (SAFT) to predict

the thermodynamic properties of reservoir fluids,

including brine, at reservoir conditions.

o Developed unified advanced models (FT-SAFT/FV-

SAFT) to predict the viscosity of gas/liquid/supercritical

fluids for carbon dioxide and alkanes.

o Developed an advanced model (Multiple Mixing Cells

model coupled with key tie line approach) to predict

Minimum Miscibility Pressure (MMP) for model oils.

Refereed publications: 10

Submitted: 2

Achievement

Experimental component:

o Built a slim tube apparatus for Minimum Miscibility

Pressure (MMP) measurements

o Measured MMP for model oils and Wyoming oils.

o Investigated the effects of injected gas composition on

MMP.

Refereed publications: 2

Future Work(2007-2008)

Theoretical component:

o Extend our model to predict the MMPs of systems with

increasing degree of complexity.

Experimental component:

o Continue supporting the modeling work and measuring

the MMPs of Wyoming oils.

o Study the effects of operating conditions, gas composition,

and brine on oil recovery in CO2 flooding.

280 300 320 340 360 380 400 420 440 460 480 500

0

400

800

1200

1600

2000

2400

6

5

4

3

2

Vis

cosi

ty [

10

-6 P

]

Temperature [K]

280 300 320 340 360 380 400 420 440 460 480 500

2000

4000

6000

8000

10000

12000

14000

16000

1800012

10

9

87

Vis

cosi

ty [

10

-6 P

]

Temperature [K]

Viscosity of pure n-alkanes at P = 200 bar; broken lines are calculated using our model

(numbers n are for CnH2n+2); circles: experimental data

Viscosity of alkanes

0 100 800 900 10000.0

0.2

0.4

0.6

0.8

1.0

43

21

zi

i-th cell

0.00 0.25 0.50 0.75 1.00

0.00

0.25

0.50

0.75

1.00 0.00

0.25

0.50

0.75

1.00

4

3

2 1

Injected gas: C1

Model oil: 50% C4 + 50% C10

T = 344 K, P = 16 MPa

fg = 1, GOR = 0.3

C1

C4

C10

bubble curve dew curve

critical point

injection tie line

initial tie line

Process simulation results: Ternary system [Zhao, et al., 2006]

0.0 0.2 0.4 0.6 0.8 1.0 1.20.0

20.0

40.0

60.0

80.0

100.0

(a)

Oil

reco

vry

,%O

OIP

PV of CO2injected

1200 Psia

1400 Psia

1500 Psia

1600 Psia

1800 Psia

8.0 9.0 10.0 11.0 12.0 13.070.0

80.0

90.0

100.0

(a)

Oil

recove

ry,%

OO

IPPressure,MPa

1,2 PV

Breakthrough

MMP Measurements for Wyoming Oil

0 2 4 6 8 10

0

10

20

30

40

50

60

Pe

rce

nta

ge

of

MM

P in

cre

ase

Percentage of oxygen

Cottonwood Creek oil

Model oil

0 2 4 6 8 10

10

11

12

13

14

15

16

MM

P, M

Pa

Presentage of impurity in CO2

O2

N2

Effects of O2 and N2 on MMP

1. Yang, F.; Zhao, G-B.; Adidharma, H.;Towler, B.F.; Radosz, M.. The effect of oxygen on minimum miscibility pressure

in carbon dioxide flooding, Ind. Eng. Chem. Res. 2007, in print.

2. Zhao, G-B.; Adidharma, H.;Towler, B.F.; Radosz, M. Using a multiple-mixing-cell model to study minimum miscibility

pressure controlled by thermodynamic equilibrium tie lines. Ind. Eng. Chem. Res. 2006, 45, 7913-7923.

3. Ji, X.; Adidharma, H. Ion-based SAFT2 to represent aqueous single- and multiple-salt solutions at 298.15 K.

Industrial & Engineering Chemistry Research 2006, 45, 7719-7728.

4. Ji, X.; Tan, S. P.; Adidharma, H.; Radosz, M. Statistical Associating Fluid Theory Coupled with Restrictive Primitive

Model Extended to Bivalent Ions. SAFT2: II. Brine/Seawater Properties Predicted. Journal of Physical Chemistry

Part B 2006, 110, 16700-16706.

5. Tan, S. P.; Ji, X.; Adidharma, H.; Radosz, M. Statistical Associating Fluid Theory Coupled with Restrictive Primitive

Model Extended to Bivalent Ions. SAFT2: I. Single Salt + Water Solutions. Journal of Phys. Chem. B 2006, 110,

16694-16699.

6. Kiselev, S. B.; Ely, J. F.; Tan, S. P.; Adidharma, H.; Radosz, M. HRX-SAFT Equation of State for Fluid Mixtures:

Application to Binary Mixtures of Carbon Dioxide, Water, and Methanol. Industrial Engineering & Chemical

Research 2006, 45, 3981-3990.

7. Tan, S. P.; Adidharma, H.; Towler, B. F.; Radosz, M. Friction Theory Coupled with Statistical Associating Fluid

Theory for Estimating the Viscosity of n-Alkane Mixtures. Industrial & Engineering Chemistry Research 2006, 45,

2116-2122.

8. Ji, X.; Tan, S. P.; Adidharma, H.; Radosz, M. The SAFT1-RPM Approximation Extended to Phase Equilibria and

Densities of CO2-H2O and CO2-H2O-NaCl Systems. Industrial & Engineering Chemistry Research 2005, 44, (22),

8419-8427.

9. Ji, X.; Tan, S. P.; Adidharma, H.; Radosz, M. Statistical Associating Fluid Theory Coupled with Restricted Primitive

Model to Represent Aqueous Strong Electrolytes: Multiple Salt Solutions. Industrial & Engineering Chemistry

Research 2005, 44, 7584-7590.

10. Tan, S. P.; Adidharma, H.; Towler, B. F.; Radosz, M. Friction Theory and Free-Volume Theory Coupled with

Statistical Associating Fluid Theory for Estimating the Viscosity of Pure n-Alkanes. Industrial & Engineering

Chemistry Research 2005, 44, (22), 8409-8418.

11. Tan, S. P.; Adidharma, H.; Radosz, M. Statistical Associating Fluid Theory Coupled with Restricted Primitive Model

to Represent Aqueous Strong Electrolytes. Industrial & Engineering Chemistry Research 2005, 44, 4442-4452.

Publications

Enhanced Oil Recovery Using CO2

• There is a current supply shortage

• Other sources are the Exxon Shute Creek plant

• The Madden Gas Plant

• Big Supplies of CO2 from the flue gas of several coal fired Power Plants in Wyoming

• Separation technology is critical

CO2 Separation

Key to economically viable CO2-based

enhanced oil recovery.

Amine absorption process ~ $40/ton CO2

$2.25/MCF CO2

CO2-separation alone will add $18

cost to each barrel of oil

Current Subprojects

• New CO2 absorbents and adsorbents

Poly(ionic liquid) absorbents

Carbonaceous adsorbent

New processes for CO2 desorption

• New polymer membrane for CO2

separation

Poly(ionic liquid) membrane

Nanocomposite membrane

CO2 Sorbents• To develop and test novel adsorbents and

adsorption cycles or processes for capture

of CO2 using pressure or temperature-swing

process

• To determine the impact of process parameters

(cycle time, cycle configuration, temperature) on

CO2 capture efficiency.

• To determine capital and power requirements by

using simulation tools to scale up to appropriate

size.

• To acquire sufficient process performance data

for the adsorption processes developed so as to

permit technical and economic assessment of the

viability of adsorption technologies

Example of CO2 PSA Process

Issues of Current CO2 Sorbents

• High energy consumption

• Amine loss and degradation

• Equipment corrosion.

• Costly zeolites ($80,000/ton)

Our Focus

Low heat capacity

Non-volatility

No-corrosion

Versatility

Tailored capacity/properties

Low cost

Our New CO2 absorbents and adsorbents

Poly(ionic liquid) absorbents - patent pending

Carbonaceous adsorbents - patent pending

Poly(ionic liquid)s for CO2

separation• Unexpectedly, we found that

simply making the ionic liquids based on imidazolium into polymeric forms significantly increased the CO2 absorption capacity compared with ionic liquids.

• With fast CO2 absorption and desorption rate, reversible desorption and feasibility to fabrication, these polymers are very prospect as sorbent and membrane materials for CO2separation. BF4

N

N

*

*

n

P[VBBI][BF4]

NN+

BF4-

[bmim][BF4]

CO2 absorption of poly(ionic liquid) based on ammonium and their monomers

0

2

4

6

8

10

12

0 100 200 300 400 500

Time (min)

CO

2 M

ole

(%

)

P[VBTMA][BF4]

P[MATMA][BF4]

P[VBBI][BF4]

[bimm][BF4]

[VBTMA][BF4]

[MATMA][BF4]

CO2 absorption of the poly(ionic liquid) based on ammonium and imidazolium,

their corresponding monomers and an ionic liquid as a function of time (592.3

mmHg CO2, 22 °C).

Cycles of CO2 sorption and desorption

0

2

4

6

8

10

0 100 200 300 400 500Time (min)

CO

2 M

ol. %

0

0.3

0.6

0.9

1.2

0 200 400 600 800Time (min)

CO

2 M

ol.%

N BF4-

**

n

P[VBTMA][BF4]

NN+

BF4-

Faster sorption and desorptionReversible sorption

H2C C

CH3

C O

O

NBF4

** n

P[MATMA][BF4]

a b

a

b

Ionic liquid

High CO2/nitrogen selectivity

0

2

4

6

8

10

12

0 50 100 150 200

Time (min)

CO

2 M

ol. %

CO2

N2N BF4

-

**

n

P[VBTMA][BF4]

Carbonaceous Adsorbents

• Much lower cost

• High capacity

• Tested in lab

• Plan to test in the UW power plant

• Patent pending

New CO2-desorption process

• Current approach- steam heating

Low efficiency

Deteriorate the sorbents, making the sorbents be used only for several cycles

Our New approachHigh EfficiencyDo not affect the sorbents; sorbents

can be numerous cyclesPatent pending

New Polymer membranes

Ionic Liquid Polymer Membrane

1

10

100

0.1 1 10 100 1000 10000 100000CO2 permeability (Barrer)

CO

2/N

2 P

erm

sele

ctivity

Representative polymers

P[MATMA][BF4]-g-PEG 2000

P[VBTMA][BF4]-g-PEG 2000

[emim][dca]

1

10

100

0.1 1 10 100 1000 10000 100000

CO2 permeability (Barrer)

CO

2/N

2 p

erm

se

lec

tiv

ity

Representative polymers

BPPOdp/silica (10nm) composite membranes

0%9% 17%

23%

BPPOdp/10 nm-silica

nanocomposite membranes

Polymer-Carbon Nanotube Membranes

1

10

100

0.1 1 10 100 1000 10000 100000

CO2 permeability (Barrer)

CO

2/N

2 p

erm

se

lec

tiv

ity

Representative polymers

BPPOdp/SWNT composite membranes

0%5% 17%

9%

a

Refereed Journals1. A..Blasig, X. Hu; S. P. Tan; J. Tang; Y. Shen, M. Radosz, Carbon Dioxide Solubility in Polymerized Ionic Liquids Containing

Ammonium and Imidazolium Cations from Magnetic Suspension Balance: P[VBTMA][BF4] and P[VBMI][BF4]“, submitted to Industrial & Engineering Chemistry Research.

2. H. Cong, X. Hu, J. Tang, M. Radosz, Y. Shen, “Nanocomposite membranes of brominated poly(2,6-diphenyl-1,4-phenylene oxide) for gas separation”, Industrial & Engineering Chemistry Research, accepted

3. H. Cong, J. Zhang, M. Radosz, Y. Shen, “Carbon nanotube composite membranes of brominated poly(2,6-diphenyl-1,4-phenylene oxide) for gas separation”, Journal of Membrane Science, submitted.

4. X. Hu, H. Cong, Y. Shen, M. Radosz, “Nanocomposite membranes for CO2 separations: Silica/brominated poly(phenylene oxide)]" Industrial & Engineering Chemistry Research, accepted.

5. H. Cong, M. Radosz, B. F. Towler, Y. Shen,* Polymer-inorganic nanocomposite membranes for gas separation, Separation and Purification Technology, in press.

6. X. Hu, J. Tang, A. Blasig, Y. Shen, M. Radosz, “CO2 permeability, diffusivity and solubility in polyethylene glycol-grafted polyionic membranes and their CO2 selectivity relative to methane and nitrogen”. Journal of Membrane Science 2006, 281, 130-138.

7. J. Tang, W. Sun, H. Tang, M. Radosz, Y. Shen, “Low pressure CO2 sorption in ammonium based poly(ionic liquid)s”, Polymer, 2005,46, 12460-12467.

8. J. Tang, W. Sun, H. Tang, M. Radosz, Y. Shen, “Poly(ionic liquid)s as new materials for CO2 absorption”, Journal of Polymer Science Part A: Polymer Chemistry, 2005, 43, 5477-5489.

9. J. Tang, H. Tang, W. Sun, H. Plancher, M. Radosz, Y. Shen, “Poly(ionic liquid): A new material for enhanced and fast absorption of CO2”, Chemical Communication, 2005, 3325-3327 (also introduced in Chemical & Engineering News’s cover story “Membranes For Gas Separation” 2005, 83 (40) 49-57).

10. J. Tang, H. Tang, W. Sun, M. Radosz, Y. Shen, “Enhanced CO2-absorption of poly(ionic liquid)s”, Macromolecules 2005, 38, 2037-2039.

Refereed Preprints:1. H. Cong, X. Hu, M. Radosz, Y. Shen. Silca nanocomposite membranes of poly(2,6-dimethyl-1,4-phenylene oxide) derivatives for gas

separation. PMSE Preprints 2006, 95, 338-339.2. X. Hu, J. Tang, A. Blasig, A, Y. Shen, M. Radosz. Grafted poly(ionic liquid) membranes for CO2 separation. PMSE Preprints 2006,

95, 268.3. J. Tang, H. Tang, W. Sun, M. Radosz, Y. Shen. Carbon dioxide absorption of poly(ionic liquid)s with different ionic structures. PMSE

Preprints 2005, 93 1006-1007. 4. H. Cong, J. Tang, M. Radosz, Y. Shen. Synthesis of poly(ionic liquid)s by condensation polymerization. PMSE Preprints 2005, 93,

546-547. 5. J. Tang, H. Tang, W. Sun, M. Radosz, Y. Shen. Poly(ionic liquid)s: novel materials for CO2 absorption. PMSE Preprints 2005, 92,

681-682.6. J. Tang, H. Tang, W. Sun, M. Radosz, Y. Shen. CO2 absorption of polymers of ammonium-based ionic liquid monomers. PMSE

Preprints 2005, 92, 56-5

Academic Achievement: 10 refereed journal papers

6 refereed preprints1 paper highlighted in Chemical and Engineering News

Proprietary Documents and Plans

1 patent is granted4 patents are pending

Pilot testing scheduled in the UW Power Plant (this spring if the weather allows or summer)

1. To determine the impact of process parameters (cycle time, cycle configuration, temperature) on CO2 capture efficiency

2. To determine capital and power requirements from simulation to scale up

3. To acquire performance data to permit technical and economic assessment