Patent US3726342A successfully refreshed from Google Patents.
US3726342A
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Method of polymer flooding
Assignee: Marathon Oil Co
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Filing: 1971-03-24
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Granted: 1973-04-10
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Expires: 1991-03-24
Abstract
Abstract Polymer flooding to increase production of formation fluids from a subterranean oil-bearing reservoir of low permeability, utilizing a polymer of a specified average molecular weight with at least 5 percent by weight having an average molecular weight at least 1.2 times greater than this specified average molecular weight is improved by mechanically or physically degrading the polymer solution. This substantially decreases the tendency of the polymer solution to ''''plug'''' the formation, while only slightly decreasing its viscosity.
Inventors
- 👤 J Rhudy
- 👤 G Haws
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 21:49
CPC Classifications
C; C09; C09K; C09K8/00; C09K8/58; C09K8/588
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
23 words
The process of claim 1 wherein the high molecular weight polymer has a molecular weight of from about 500,000 to about 50, 000,000.
Claim 2
Dependent Claim
24 words
The process of claim 1 wherein the subterranean oil-bearing reservoir is characterized as having an average permeability of about 5 to about 200 millidarcies.
Claim 3
Dependent Claim
16 words
The process of claim 1 wherein the high molecular weight polymer is characterized as being viscoelastic.
Claim 4
Dependent Claim
16 words
The process of claim 1 wherein the polymer is a partially hydrolyzed, high molecular weight polyacrylamide.
Claim 5
Dependent Claim
18 words
The process of claim 1 wherein the polymer is sheared prior to its introduction into the injection means.
Claim 6
Dependent Claim
166 words
In a process for recovering crude oil from a subterranean oil-bearing reservoir having at least one injection means in fluid communication with at least one production means and wherein an aqueous solution of a high molecular weight polymer is injected into the formation to facilitate the flow of crude oil toward a production means and wherein the polymer has a predetermined average molecular weight with at least 5 percent by weight of the polymer having an average molecular weight at least about 1.2 times greater than the average molecular weight of the total polymer within the aqueous solution and wherein at least the 5 percent portion contributes significantly to reducing the permeability of the subterranean oil-bearing reservoir, the improvement comprising subjecting the polymer solution to sufficient shear force to substantially reduce the screen factor of the polymer while only slightly reducing the average molecular weight of the polymer, the overall effect being to reduce the tendency of the polymer to reduce the permeability of the reservoir.
Claim 7
Dependent Claim
22 words
The process of claim 7 wherein the high molecular weight polymer has a molecular weight from about 500,000 to about 50, 000,000.
Claim 8
Dependent Claim
24 words
The process of claim 7 wherein the subterranean oil-bearing reservoir is characterized as having an average permeability of about 5 to about 200 millidarcies.
Claim 9
Dependent Claim
16 words
The process of claim 7 wherein the high molecular weight polymer is characterized as being viscoelastic.
Claim 10
Dependent Claim
16 words
The process of claim 7 wherein the polymer is a partially hydrolyzed, high molecular weight polyacrylamide.
Claim 11
Dependent Claim
18 words
The process of claim 7 wherein the polymer is sheared prior to its introduction into the injection means.
References Cited (Backward Citations)
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US3039529A
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US3305016A
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US3180410A
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US3371714A
Cited
US3406754A
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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) | 1976-04-09 | 1976-10-09 | 1977-04-10 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-04-09 | 1980-10-09 | 1981-04-10 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-04-09 | 1984-10-09 | 1985-04-10 | $7700.00 | Window Closed / Lapsed |