US3525397A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method of temporarily plugging an earth formation
Assignee: Shell USA Inc
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Filing: 1968-12-26
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Granted: 1970-08-25
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Expires: 1988-12-26
Abstract
No abstract record available.
Inventors
- 👤 Henry C H Darley
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 03:03
CPC Classifications
E; E21; E21B; E21B43/00; E21B43/25; E21B43/26; E21B43/261; C; C09; C09K; C09K8/00; C09K8/60
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) | 1973-08-24 | 1974-02-23 | 1974-08-25 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1977-08-24 | 1978-02-23 | 1978-08-25 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1981-08-24 | 1982-02-23 | 1982-08-25 | $7700.00 | Window Closed / Lapsed |