US4404111A
Expired / Lapsed
US
⏱️ 0.0 years remaining
N,N-Dimethylacrylamide/2-acrylamido-2-methylpropane sulfonic acid copolymers for enhanced petroleum recovery
Assignee: Lyondell Chemical Technology LP
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Filing: 1981-02-06
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Granted: 1983-09-13
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Expires: 2001-02-06
Abstract
Abstract A N,N-dimethylacrylamide/2-acrylamido-2-methylpropane sulfonic acid copolymer is disclosed. The copolymer is particularly suitable for use as a viscosity control agent in an aqueous composition employed to facilitate petroleum recovery from subterranean petroleum bearing formations.
Inventors
- 👤 Le-Khac Bi
- 👤 Mary E. Dillon
- 👤 Clyde Sharik
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 20:32
CPC Classifications
C; C09; C09K; C09K8/00; C09K8/58; C09K8/588; Y; Y10; Y10S; Y10S507/00; Y10S507/935; Y10S507/936
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
100 words
In a process for enhancing petroleum recovery from a subterranean petroleum bearing formation which comprises injecting into the formation through an input well an aqueous composition having dissolved therein a polymeric viscosity control agent whereby petroleum is displaced in the formation toward at least one output well, the improvement comprising using as said agent, a random copolymer having a weight average molecular weight greater than about one million having the formula: ##STR2## said random copolymer being produced by reacting from about 98 to about 99.5 weight percent N,N-dimethylacrylamide with from about 0.5 to about 2 weight percent 2-acrylamido-2-methylpropane sulfonic acid.
Claim 2
Dependent Claim
100 words
In a process for enhancing petroleum recovery from a subterranean petroleum bearing formation which comprises injecting into the formation through an input well an aqueous composition having dissolved therein a polymeric viscosity control agent whereby petroleum is displaced in the formation toward at least one output well, the improvement comprising using as said agent, a random copolymer having a weight average molecular weight greater than about one million having the formula: ##STR2## said random copolymer being produced by reacting from about 98 to about 99.5 weight percent N,N-dimethylacrylamide with from about 0.5 to about 2 weight percent 2-acrylamido-2-methylpropane sulfonic acid.
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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) | 1986-09-12 | 1987-03-14 | 1987-09-13 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1990-09-12 | 1991-03-14 | 1991-09-13 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1994-09-12 | 1995-03-14 | 1995-09-13 | $7700.00 | Window Closed / Lapsed |