Surfactant-Alkali Phase Behavior
Adam Jackson
Larry Britton
Gary Pope
David Levitt
Varadarajan Dwarakanath
Taimur Malik
The University of Texas at Austin
CPGE
Outline
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•
•
•
CPGE
Surfactants
Crude Oil
Phase Behaviors
Conclusions
Surfactants Studied
Manufacturer
Trade (Common)
Name
Abbreviated
Chemical Name
STEPAN
Neodol N67 3 PO
C16-17 (PO)3 SO4
STEPAN
Neodol N67 5 PO
C16-17 (PO)5 SO4
STEPAN
Neodol N67 7 PO
C16-17 (PO)7 SO4
STEPAN
C1618
C16-18 AOS
STEPAN
C2024
C20-24 AOS
SHELL
C16 Xylene Sulfonate
C16 OXS
SHELL
IOS 1518
C15-18 IOS
OIL CHEM
ORS-HF66
CLARIANT
Hostapur SAS-60
CPGE
Crude Oils Studied
Operator
Burlington Resources
Cedar Hills (CH)
Occidental
Elk Hills (ELK)
Occidental Permian Ltd.
Midland Farms (MF2)
(Batch 2)*
Occidental Permian Ltd.
Midland Farms (MF3)
(Batch 3)*
* Two samples from the same field
CPGE
Field
Phase Behavior Parameters
•
•
•
•
•
•
CPGE
New Surfactants
Electrolyte Concentration
Sodium Carbonate
Sec-Butyl Alcohol (SBA) Concentration
Crude Oil (and associated Temperature)
Polymers
Optimal Salinity for N67-7PO and IOS-1518
with Midland Farms Crude
24.0
0.75% C16-17 (PO)7 SO4, 0.25% C15-18 IOS, 2% SBA, 0.02% Na2CO3
oil
20.0
Solublization Ratio
water
16.0
12.0
DOE 201: MF3
Temp. = 38 C
21 days after mixing
8.0
4.0
0.0
0.0
0.5
1.0
1.5
2.0
Sodium ion concentration (wt%)
CPGE
2.5
3.0
Equilibration at Optimal Salinity
25
0.75% C16-17 (PO)7 SO4, 0.25% C15-18 SO3, 2% SBA, 0.02% Na2CO3
oil
Solubilization Ratio
20
water
15
10
DOE 201: MF3
Na+ = 1.7 wt%
Temp. = 38 C
5
0
0
5
10
Time [days]
CPGE
15
20
Equilibration Near Optimum Salinity
25
oil
0.75% C16-17 (PO)7 SO4, 0.25% C15-18 SO3, 2% SBA, 0.02% Na2CO3
water
Solubilization Ratio
20
15
10
DOE 201:MF3
Na+ = 1.6 wt%
Temp. = 38 C
5
0
0
5
10
Time [days]
CPGE
15
20
Effect of Sodium Carbonate on
Equilibration Time
25
0.75% C16-17 (PO)7 SO4, 0.25% C15-18 SO3, 2% SBA, 1.02% Na2CO3
oil
Solubilization Ratio
20
water
15
10
DOE 203: MF3
Na+ = 1.9 wt%
Temp. = 38 C
5
0
0
2
4
6
8
Time [days]
CPGE
10
12
14
Effect of Varying Sodium Carbonate
Concentration on Equilibration Time
25
0.75% C16-17 (PO)7 SO4, 0.25% C15-18 SO3, 2% SBA
Solubilization Ratio
20
oil (0.02%Na2CO3, 1.6 wt% Na+)
water (0.02%Na2CO3, 1.6 wt% Na+)
oil (1.02%Na2CO3, 1.9wt% Na+)
water (1.02%Na2CO3, 1.9wt% Na+)
oil (2.02%Na2CO3, 2.0wt% Na+)
water (2.02%Na2CO3, 2.0wt% Na+)
15
10
5
0
0
CPGE
2
4
6
8
10
Time [days]
12
14
16
18
20
Effect of Alcohol on Phase Behaviors with
N67-7PO, IOS-1518 and MF Crude at 38C
d.n.e. Did not equilibrate
CPGE
Effect of Sodium Carbonate on Optimal Salinity
for Elk Hills Crude with AOS and SBA
25
2% C20-24 AOS, 4% SBA
Oil Sol Ratio After 21 Days
(0.02% Na2CO3)
20
Solubilization Ratio
Water Sol Ratio After 21 Days
(0.02% Na2CO3)
Oil Sol Ratio After 13 Days
(1.02% Na2CO3)
15
Water Sol Ratio After 13 Days
(1.02% Na2CO3)
10
ELK Hills Crude
Temp. = 100 C
5
0
0.0
CPGE
0.2
0.4
0.6
0.8
1.0
1.2
1.4
Sodium Concentration (wt %)
1.6
1.8
2.0
Effect of Sodium Carbonate on Equilibration
Time with Elk Hills Crude
20
oil (0.02% Na2CO3, 0.8% Na+)
oil (1.02% Na2CO3, 1.0% Na+)
water (0.02% Na2CO3, 0.8% Na+)
water (1.02% Na2CO3, 1.0% Na+)
Solubilization Ratio
15
10
5
Elk Hills Crude
Temp. = 100 C
0
0
CPGE
10
20
30
40
50
Time, days
60
70
80
90
100
Summary and Conclusions
• Na2CO3 has little effect on MF solubilization
• Alcohol reduces equilibration time, viscosity and
solubilization
– N67-7PO and IOS-1518 can exhibit reasonable
equilibration times while maintaining >10
solubilization with SBA
• Na2CO3 improves Elk Hills solubilization ratio
• Alcohol shortens phase separation time with Elk
Hills crude oil
• HPAM had little if any effect on the equilibrated
phase behavior
CPGE
Slug and polymer drive composition for core
flood D6
Pore Volumes
CPGE
Mixture
0.8
0.75% N67[7PO], 0.25% IOS C1518, 2% SBA
0.02% Na2CO3, 4.45% NaCl
1500 ppm Flopaam 3330S
0.2
2% SBA
3.05% NaCl
1500 ppm Flopaam 3330S
1.5
1.93% NaCl
1200 ppm Flopaam 3330S
Surfactant selection for MF Core Flood
• Surfactant formulation was selected for core
flooding because it showed
– Good solubilization ratio at optimum salinity
– Optimum salinity within the desired range of 2% to 6%
TDS corresponding to Midland Farms brines
– Microemulsion viscosity acceptable
– Better dilution behavior than with AOS
– Aqueous phase stable and clear at injected salinity
– Compatible with HPAM polymer
• Polymer selected for core flood
– Higher viscosity than low molecular weight HPAM
used in first core flood and RF expected to be high for
good mobility control
– Compatible with surfactant at salinity of slug and drive
CPGE
2% C20-24 AOS, 4% SBA, 0.02% Na2CO3 with ELK at 100C
CPGE