US3800877A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Process of flooding oil-bearing formations using aldehydes as oxygen scavengers in polymer solutions
Assignee: Marathon Oil Co
•
Filing: 1972-08-28
•
Granted: 1974-04-02
•
Expires: 1992-08-28
Abstract
Abstract Flooding of oil-bearing subterranean formations with aqueous solutions of partially hydrolyzed, high molecular weight polyacrylamides or copolymers of acrylamide and acrylic acid wherein the aqueous solution contains at least 0.1 ppm of dissolved oxygen and the oxygen adversely influences the mobility imparted by the polymer, is improved by incorporating 5-1000 ppm of a water-soluble aldehyde (preferably formaldehyde) into the aqueous solution to form a complex with the oxygen and thereby inhibit the adverse effects of the oxygen.
Inventors
- 👤 B Knight
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 15:31
CPC Classifications
C; C09; C09K; C09K8/00; C09K8/58; C09K8/588
Claims Analysis
Total Claims: 17
Claim 1
Independent Claim
20 words
The process of claim 1 wherein about 5 to about 1,000 ppm of formaldehyde is incorporated into the aqueous solution.
Claim 2
Dependent Claim
20 words
The process of claim 1 wherein about 25 to about 750 ppm of formaldehyde is incorporated into the aqueous solution.
Claim 3
Dependent Claim
20 words
The process of claim 1 wherein about 50 to about 500 ppm of formaldehyde is incorporated into the aqueous solution.
Claim 4
Dependent Claim
19 words
The process of claim 1 wherein the polymer has an average molceular weight of at least about one million.
Claim 5
Dependent Claim
24 words
The process of claim 1 wherein a slug of micellar dispersion is injected into the formation Previous to the injection of the polymer solution.
Claim 6
Dependent Claim
19 words
The process of claim 1 whereIn the dissolved oxygen concentration in the water is at least about 1.0 ppm.
Claim 7
Dependent Claim
16 words
The process of claim 1 wherein the polymer is a partially hydrolyzed, high molecular weight polyacrylamide.
Claim 8
Dependent Claim
16 words
The process of claim 1 wherein the polymer is a copolymer of acrylamide and sodium acrylate.
Claim 9
Dependent Claim
109 words
A process of improving the mobility of control of flooding an oil-bearing subterranean formation wherein an aqueous solution comprised of a partially hydrolyzed, high molecular weight polyacrylamide is injected into the formation and displaced therethrough to improve the mobility control of the flooding process and wherein the water contains at least about 0.1 ppm (based on the water) of dissolved oxygen which adversely affects mobility control through degradation of the polyacrylamide, the improvement comprising incorporating into the aqueous solution about 5 to about 1,000 ppm of a water-soluble aldehyde to complex with the oxygen and thus inhibit the adverse influence the oxygen has upon degrading the aqueous polyacrylamide solution.
Claim 10
Dependent Claim
10 words
The process of claim 10 wherein the aldehyde is formaldehyde.
Claim 11
Dependent Claim
15 words
The process of claim 10 the aldehyde is an equilibrium mixture of formaldehyde and paraformaldehyde.
Claim 12
Dependent Claim
23 words
The process of claim 10 wherein the concentration of the aldehyde is about 25 to about 750 ppm, based on the aqueous solution.
Claim 13
Dependent Claim
23 words
The process of claim 10 wherein the concentration of the aldehyde is about 50 to about 500 ppm, based on the aqueous solution.
Claim 14
Dependent Claim
114 words
A process of improving the mobility control of flooding an oil-bearing subterranean formation wherein an aqueous solution comprised of a copolymer of acrylamide and acrylic acid or an alkali metal salt thereof is injected into the formation and displaced therethrough to improve the mobility control of the flooding process and wherein the water contains at least about 0.1 ppm (based on the water) of dissolved oxygen which adversely affects mobility control through degradation of the copolymer, the improvement comprising incorporating into the aqueous solution about 5 to about 1,000 ppm of a water-soluble aldehyde to complex with the oxygen and thus inhibit the adverse influence the oxygen has upon degrading the aqueous copolymer solution.
Claim 15
Dependent Claim
10 words
The process of claim 15 wherein the aldehyde is formaldehyde.
Claim 16
Dependent Claim
16 words
The process of claim 15 wherein the aldehyde is an equilibrium mixture of formaldehyde and paraformaldehyde.
Claim 17
Dependent Claim
23 words
The process of claim 15 wherein the concentration of the aldehyde is about 50 to about 500 ppm, based on the aqueous solution.
References Cited (Backward Citations)
US3106525A
Cited
US2827964A
Cited
US3053765A
Cited
US3085063A
Cited
US3625888A
Cited
US3580337A
Cited
US3634232A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1977-04-01 | 1977-10-01 | 1978-04-02 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-04-01 | 1981-10-01 | 1982-04-02 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-04-01 | 1985-10-01 | 1986-04-02 | $7700.00 | Window Closed / Lapsed |