US3953341A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Stabilization of polymer solutions
Assignee: Calgon Corp
•
Filing: 1974-05-08
•
Granted: 1976-04-27
•
Expires: 1994-05-08
Abstract
Abstract Use of methylolated water-soluble polymers to maintain or increase solution viscosity of polymer compositions useful in oil recovery processes.
Inventors
- 👤 Fred David Martin
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 05:12
CPC Classifications
C; C09; C09K; C09K8/00; C09K8/58; C09K8/588; Y; Y10; Y10S; Y10S507/00; Y10S507/935; Y10S507/936
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
107 words
A process for the secondary or tertiary recovery of petroleum from subterranean formations penetrated by an injection well and a producing well which comprises introducing into said reservoir through said injection well a substantially oxygen free viscosity improving displacing medium to displace said petroleum from said subterranean formation, said displacing medium comprising water and a methylolated high molecular weight water-soluble copolymer of acrylamide and 2-acrylamido methylpropane sulfonic acid having a molecular weight of at least 200,000 wherein from about 0.1 to about 10 moles of formaldehyde is reacted for each mole of acrylamide in said polymer in order to increase the solution viscosity of the displacing medium.
Claim 2
Dependent Claim
107 words
A process for the secondary or tertiary recovery of petroleum from subterranean formations penetrated by an injection well and a producing well which comprises introducing into said reservoir through said injection well a substantially oxygen free viscosity improving displacing medium to displace said petroleum from said subterranean formation, said displacing medium comprising water and a methylolated high molecular weight water-soluble copolymer of acrylamide and 2-acrylamido methylpropane sulfonic acid having a molecular weight of at least 200,000 wherein from about 0.1 to about 10 moles of formaldehyde is reacted for each mole of acrylamide in said polymer in order to increase the solution viscosity of the displacing medium.
Claim 3
Dependent Claim
19 words
A process as in claim 1 whereby the reservoir temperature is utilized to cause the methylolation reaction to occur.
Claim 4
Dependent Claim
16 words
A process as in claim 1 wherein the polymer and formaldehyde are preheated prior to injection.
References Cited (Backward Citations)
US3039529A
Cited
US3085063A
Cited
US3343601A
Cited
US3679000A
Cited
US3747676A
Cited
US3800877A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1979-04-27 | 1979-10-27 | 1980-04-27 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1983-04-27 | 1983-10-27 | 1984-04-27 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1987-04-27 | 1987-10-27 | 1988-04-27 | $7700.00 | Window Closed / Lapsed |