US3443640A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method of reducing the permeability of a subsurface stratum
Assignee: Phillips Petroleum Co
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Filing: 1967-06-05
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Granted: 1969-05-13
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Expires: 1987-06-05
Abstract
No abstract record available.
Inventors
- 👤 Frederick A Klein
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-03 13:44
CPC Classifications
C; C09; C09K; C09K17/00; C09K17/40; C09K17/42; C09K8/00; C09K8/50; C09K8/504; C09K8/5045; C09K8/60; E; E21; E21B; E21B33/00; E21B33/10; E21B33/13; E21B33/138
Claims Analysis
Total Claims: 0
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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) | 1972-05-12 | 1972-11-11 | 1973-05-13 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1976-05-12 | 1976-11-11 | 1977-05-13 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1980-05-12 | 1980-11-11 | 1981-05-13 | $7700.00 | Window Closed / Lapsed |