US3915230A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Surfactant oil recovery process
Assignee: Texaco Inc
•
Filing: 1974-05-31
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Granted: 1975-10-28
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Expires: 1994-05-31
Abstract
Abstract The efficiency of an oil recovery process of the type wherein an aqueous surfactant solution is injected into a subterranean, petroleum-containing formation is increased by determining the optimum range of salinity and hardness, e.g. calcium and magnesium, for the particular surfactant being used, and formulating an aqueous preflush solution, the salinity and hardness of which are within the range for optimum surfactant effectiveness, and adding an effective amount of hydrophilic polymer to yield a suitable viscosity greater than the formation water viscosity, and injecting the aqueous preflush solution into the formation prior to injection of the surfactant solution. The viscous, controlled salinity and hardness solution displaces the formation water effectively, thereby insuring that the salinity and hardness of the surfactant solution will be at or near an optimum value for oil recovery. Suitable hydrophilic polymers include polyacrylamide, polysaccharide, polyvinyl aromatic sulfonate, polyethylene oxide, methyl cellulose, or carboxy methyl cellulose.
Inventors
- 👤 Kenoth H Flournoy
- 👤 Joseph T Carlin
- 👤 Ricardo L Cardenas
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 19:14
CPC Classifications
C; C09; C09K; C09K8/00; C09K8/58; C09K8/584; E; E21; E21B; E21B43/00; E21B43/16; E21B43/20
Claims Analysis
Total Claims: 22
Claim 1
Independent Claim
125 words
IN A METHOD OF RECOVERING PETROLEUM FROM A POROUS, SUBTERRANEAN, PETROLEUM-CONTAINING FORMATION PENETRATED BY AT LEAST ONE INJECTION WELL AND AT LEAST ONE PRODUCTION WELL, WHEREIN A SURFACTANT SOLUTION IS INJECTED INTO THE FORMATION, THE IMPROVEMENT FOR INCREASING THE EFFICIENCY OF THE SURFACTANT WHICH COMPRISES: A. DETERMINING THE RANGE OF SALINITY AND POLYVALENT ION CONCENTRATIONS FOR WHICH THE SURFACTANT PRODUCES THE MINIMUN INTERFACIAL TENSION BETWEEN WATER AND FORMATION PETROLUM, AND B. INJECTING AN AQUEOUS SOLUTION OF A HYDROPHILIC POLYMERIC VISCOSITY INCREASING MATERIAL, SAID AQUEOUS PREFLUSH SOLUTION HAVING A SALINITY AND POLYVALENT ION CONCENTRATION WITHIN THE OPTIMUM PERFORMANCE RANGE AS DETERMINED IN STEP (A), INTO THE FORMATION PROIR TO INJECTING THE SURFACTANT SOLUTION, TO DISPLACE THE FORMATION WATER THROUGH THE FORMATION AHEAD OF THE SURFACTANT SOLUTION.
Claim 2
Dependent Claim
125 words
IN A METHOD OF RECOVERING PETROLEUM FROM A POROUS, SUBTERRANEAN, PETROLEUM-CONTAINING FORMATION PENETRATED BY AT LEAST ONE INJECTION WELL AND AT LEAST ONE PRODUCTION WELL, WHEREIN A SURFACTANT SOLUTION IS INJECTED INTO THE FORMATION, THE IMPROVEMENT FOR INCREASING THE EFFICIENCY OF THE SURFACTANT WHICH COMPRISES: A. DETERMINING THE RANGE OF SALINITY AND POLYVALENT ION CONCENTRATIONS FOR WHICH THE SURFACTANT PRODUCES THE MINIMUN INTERFACIAL TENSION BETWEEN WATER AND FORMATION PETROLUM, AND B. INJECTING AN AQUEOUS SOLUTION OF A HYDROPHILIC POLYMERIC VISCOSITY INCREASING MATERIAL, SAID AQUEOUS PREFLUSH SOLUTION HAVING A SALINITY AND POLYVALENT ION CONCENTRATION WITHIN THE OPTIMUM PERFORMANCE RANGE AS DETERMINED IN STEP (A), INTO THE FORMATION PROIR TO INJECTING THE SURFACTANT SOLUTION, TO DISPLACE THE FORMATION WATER THROUGH THE FORMATION AHEAD OF THE SURFACTANT SOLUTION.
Claim 3
Dependent Claim
34 words
A method as recited in claim 1 wherein the hydrophilic polymeric viscosity increasing material is selected from the group consisting of polyacrylamide, polysaccharide, methyl cellulose, carboxy methyl cellulose, polyvinyl aromatic sulfonate and polyethylene oxide.
Claim 4
Dependent Claim
14 words
A method as recited in claim 2 wherein the hydrophilic polymeric material is polyacrylamide.
Claim 5
Dependent Claim
14 words
A method as recited in claim 2 wherein the hydrophilic polymeric material is polysaccharide.
Claim 6
Dependent Claim
15 words
A method as recited in claim 2 wherein the hydrophilic polymeric material is methyl cellulose.
Claim 7
Dependent Claim
16 words
A method as recited in claim 2 wherein the hydrophilic polymeric material is polyvinyl aromatic sulfonate.
Claim 8
Dependent Claim
15 words
A method as recited in claim 2 wherein the hydrophilic polymeric material is polyethylene oxide.
Claim 9
Dependent Claim
29 words
A method as recited in claim 1 wherein the concentration of hydrophilic polymeric material in the aqueous preflush solution is from about 25 to about 2,000 parts per million.
Claim 10
Dependent Claim
28 words
A method as recited in claim 1 wherein the concentration of polymeric material in the aqueous preflush solution is from about 200 to about 500 parts per million.
Claim 11
Dependent Claim
26 words
A method as recited in claim 1 wherein from about 0.2 to about 0.5 pore volumes of the aqueous preflush solution is injected into the formation.
Claim 12
Dependent Claim
26 words
A method as recited in claim 1 wherein from about 0.1 to about 0.3 pore volumes of the aqueous preflush solution is injected into the formation.
Claim 13
Dependent Claim
32 words
A method as recited in claim 1 wherein the concentration of hydrophilic polymer in the aqueous preflush solution is decreased with time as the aqueous preflush solution is injected into the formation.
Claim 14
Dependent Claim
54 words
A method as recited in claim 1 wherein an isolation slug of from about 0.05 to about 0.5 pore volumes of water having a salinity less than the salinity of the formation water is injected into the formation after the injection of the aqueous preflush solution and before the injection of the surfactant solution.
Claim 15
Dependent Claim
24 words
A method as recited in claim 1 wherein the salinity of the aqueous preflush solution is from 0 to about 20,000 parts per million.
Claim 16
Dependent Claim
26 words
A method as recited in claim 1 wherein the concentration of polyvalent ions in the preflush is from about 0 to about 18,000 PARTS per million.
Claim 17
Dependent Claim
26 words
A method as recited in claim 1 wherein the optimum salinity and polyvalent ion concentration for minimum interfacial tension production is determined by capillary displacement tests.
Claim 18
Dependent Claim
42 words
A method as recited in claim 1 comprising the additional step of determining the pH at which the surfactant produces the minimum interfacial tension and adjusting the pH of the aqueous preflush solution to a value essentially equal to the determined value.
Claim 19
Dependent Claim
24 words
A method as recited in claim 17 wherein the pH of the surfactant solution is essentially equal to the pH of the preflush solution.
Claim 20
Dependent Claim
22 words
A method as recited in claim 1 wherein the salinity and hardness of surfactant solution is essentially equal to the preflush solution.
Claim 21
Dependent Claim
40 words
A method as recited in claim 1 wherein the aqueous solution of a hydrophilic polymeric viscosity increasing material additionally contains sacrificial agents to lower adsorption of surfactant from the surfactant solution injected after the aqueous solution of hydrophilic polymeric material.
Claim 22
Dependent Claim
18 words
A method as recited in claim 20 wherein the sacrificial agents are added to lower adsorption of polymer.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1978-10-27 | 1979-04-28 | 1979-10-28 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-10-27 | 1983-04-28 | 1983-10-28 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-10-27 | 1987-04-28 | 1987-10-28 | $7700.00 | Window Closed / Lapsed |