Patent US3837400A successfully refreshed from Google Patents.
US3837400A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Selective plugging process
Assignee: Individual
•
Filing: 1972-12-15
•
Granted: 1974-09-24
•
Expires: 1992-12-15
Abstract
Abstract Channels in a water flood oil zone are plugged by injection of a hydroxide solution such as sodium hydroxide. The hydroxide solution is isolated from the magnesium bearing connate water in the vicinity of the wellbore by an isolating slug of low magnesium water.
Inventors
- 👤 W Martin
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 12:57
CPC Classifications
E; E21; E21B; E21B33/00; E21B33/10; E21B33/13; E21B33/138; C; C09; C09K; C09K8/00; C09K8/50; C09K8/504; C09K8/5045
Claims Analysis
Total Claims: 3
Claim 1
Independent Claim
21 words
The invention as defined in claim 1 wherein said isolation of said hydroxide solution by first m. injecting low magnesium water.
Claim 2
Dependent Claim
19 words
The invention as defined in claim 2 with an additional limitation of n. said hydroxide solution being sodium hydroxide.
Claim 3
Dependent Claim
31 words
The invention as defined in claim 3 with an additional limitation of o. said hydroxide solution also cleaning oil from the formation in the zone before reacting with said magnesium salts.
References Cited (Backward Citations)
US2042011A
Cited
US2272672A
Cited
US2156220A
Cited
US2747670A
Cited
US2837163A
Cited
US2807324A
Cited
US3530937A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1977-09-23 | 1978-03-25 | 1978-09-24 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-09-23 | 1982-03-25 | 1982-09-24 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-09-23 | 1986-03-25 | 1986-09-24 | $7700.00 | Window Closed / Lapsed |