US4420598A
Expired / Lapsed
US
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Secondary recovery process using brine soluble terpolymers
Assignee: Texaco Inc
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Filing: 1981-08-06
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Granted: 1983-12-13
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Expires: 2001-08-06
Abstract
Abstract Hydrocarbons are recovered from a subterranean hydrogen-bearing formation penetrated by an injection well and a production well by displacing hydrocarbons toward the production well using a drive fluid such as water thickened with a terpolymer of acrylamide, acrylonitrile and acrylic acid or a terpolymer of acrylamide, acrylonitrile and acrylic acid alkoxylated with ethylene oxide. If desired, the drive fluid may be saturated with carbon dioxide and/or natural gas at the injection pressure.
Inventors
- 👤 Abraham Morduchowitz
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-04 17:25
CPC Classifications
C; C09; C09K; C09K8/00; C09K8/58; C09K8/588; E; E21; E21B; E21B43/00; E21B43/16; E21B43/164; Y; Y10; Y10S; Y10S507/00; Y10S507/935; Y10S507/936
Claims Analysis
Total Claims: 3
Claim 1
Independent Claim
77 words
A brine-soluble terpolymer comprising recurring units of: ##STR4## wherein x, y and z represent the weight percent of the respective units in the terpolymer and x ranges from about 50 to about 60 weight percent, y ranges from about 20 to about 30 weight percent and z ranges from about 10 to about 20 weight percent and wherein M is the radical --(CH.sub.2 CH.sub.2 O).sub.n H wherein n is an integer of from 1 to 3 inclusive.
Claim 2
Dependent Claim
77 words
A brine-soluble terpolymer comprising recurring units of: ##STR4## wherein x, y and z represent the weight percent of the respective units in the terpolymer and x ranges from about 50 to about 60 weight percent, y ranges from about 20 to about 30 weight percent and z ranges from about 10 to about 20 weight percent and wherein M is the radical --(CH.sub.2 CH.sub.2 O).sub.n H wherein n is an integer of from 1 to 3 inclusive.
Claim 3
Dependent Claim
18 words
The terpolymer of claim 1 wherein the number average molecular weight ranges from about 10,000 to about 2,000,000.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1986-12-12 | 1987-06-13 | 1987-12-13 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1990-12-12 | 1991-06-13 | 1991-12-13 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1994-12-12 | 1995-06-13 | 1995-12-13 | $7700.00 | Window Closed / Lapsed |