Patent US2425193A successfully refreshed from Google Patents.
US2425193A
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Well control system
Assignee: Shell Development Co
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Filing: 1944-12-26
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Granted: 1947-08-05
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Expires: 1964-12-26
Abstract
No abstract record available.
Inventors
- 👤 Paul E Lehr
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-22 21:45
CPC Classifications
E; E21; E21B; E21B21/00; E21B21/12; C; C09; C09K; C09K8/00; C09K8/02; E21B21/02
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) | 1950-08-04 | 1951-02-03 | 1951-08-05 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1954-08-04 | 1955-02-03 | 1955-08-05 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1958-08-04 | 1959-02-03 | 1959-08-05 | $7700.00 | Window Closed / Lapsed |