US4428429A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method for sweep improvement utilizing gel-forming lignins
Assignee: BP Corp North America Inc
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Filing: 1981-05-26
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Granted: 1984-01-31
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Expires: 2001-05-26
Abstract
Abstract Highly conductive zones of subterranean formations are treated with aqueous fluids containing gel-forming amounts of water-soluble basic lignins. Suitable treating fluids contain about 2 to about 8 wt. % sodium hydroxide solution. The lignin solutions gel within the formation due to reactivity with oil-water and/or the rock matrix. Alternately, following the injection of the gel-forming fluids, acidic gas is injected to cause gel formation.
Inventors
- 👤 Betty J. Felber
- 👤 Charles A. Christopher
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 17:21
CPC Classifications
C; C09; C09K; C09K8/00; C09K8/50; C09K8/504; C09K8/506; C09K8/508; C09K8/514
Claims Analysis
Total Claims: 20
Claim 1
Independent Claim
77 words
A method of treating a subterranean oil bearing formation penetrated by at least one injection well, and having at least one highly conductive zone therein, comprising injecting into said zone an aqueous solution containing gel-forming water-soluble basic lignins, such that as said aqueous solution moves through said zone the pH of said aqueous solution is reduced causing said aqueous solution to gel over a substantial distance from said injection well to reduce the permeability of said zone.
Claim 2
Independent Claim
77 words
A method of treating a subterranean oil bearing formation penetrated by at least one injection well, and having at least one highly conductive zone therein, comprising injecting into said zone an aqueous solution containing gel-forming water-soluble basic lignins, such that as said aqueous solution moves through said zone the pH of said aqueous solution is reduced causing said aqueous solution to gel over a substantial distance from said injection well to reduce the permeability of said zone.
Claim 3
Dependent Claim
34 words
Method of claim 1 wherein a gel is formed more quickly from said aqueous solution after injection into said injection well by injecting an acidic gas into said zone to contact with said solution.
Claim 4
Dependent Claim
14 words
Method of claim 2 wherein said method is utilized in a gas flood project.
Claim 5
Dependent Claim
15 words
Method of claim 2 wherein said aqueous solution contains about 2-10 wt % lignin solution.
Claim 6
Dependent Claim
15 words
Method of claim 4 wherein said aqueous solution contains about 2-8 wt % lignin solution.
Claim 7
Dependent Claim
11 words
Method of claim 2 wherein the acidic gas is carbon dioxide.
Claim 8
Dependent Claim
19 words
Method of claim 6 wherein the mole ratio of carbon dioxide to lignins is about 10:1 to about 110:1.
Claim 9
Dependent Claim
12 words
Method of claim 2 wherein the acidic gas is H 2 S.
Claim 10
Dependent Claim
14 words
Method of claim 1 wherein said method is utilized in a water flood project.
Claim 11
Dependent Claim
15 words
Method of claim 1 wherein formation of said gel occurs by reaction with reservoir components.
Claim 12
Dependent Claim
12 words
Method of claim 1 wherein said lignin solutions are Kraft Black Liquor.
Claim 13
Independent Claim
58 words
A method of treating a subterranean oil bearing formation penetrated by at least one injection well, and having at least one highly conductive zone therein, comprising injecting an aqueous solution containing gel-forming water-soluble basic lignins into said zone to reduce the permeability of said zone, and injecting an acidic gas into said zone to contact with said solution.
Claim 14
Independent Claim
58 words
A method of treating a subterranean oil bearing formation penetrated by at least one injection well, and having at least one highly conductive zone therein, comprising injecting an aqueous solution containing gel-forming water-soluble basic lignins into said zone to reduce the permeability of said zone, and injecting an acidic gas into said zone to contact with said solution.
Claim 15
Dependent Claim
14 words
Method of claim 12, wherein said method is utilized in a gas floor project.
Claim 16
Dependent Claim
15 words
Method of claim 12, wherein said aqueous solution contains about 2-10 wt % lignin solution.
Claim 17
Dependent Claim
15 words
Method of claim 14, wherein said aqueous solution contains about 2-8 wt % lignin solution.
Claim 18
Dependent Claim
11 words
Method of claim 12, wherein the acidic gas is carbon dioxide.
Claim 19
Dependent Claim
20 words
Method of claim 16, wherein the mole ratio of carbon dioxide to lignins is from about 10:1 to about 110:1.
Claim 20
Dependent Claim
12 words
Method of claim 12, wherein the acidic gas is H 2 S.
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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) | 1987-01-30 | 1987-08-01 | 1988-01-31 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1991-01-30 | 1991-08-01 | 1992-01-31 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1995-01-30 | 1995-08-01 | 1996-01-31 | $7700.00 | Window Closed / Lapsed |