Patent US3221812A successfully refreshed from Google Patents.
US3221812A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Use of antioxidants in underground combustion control
Assignee: Shell USA Inc
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Filing: 1963-04-25
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Granted: 1965-12-07
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Expires: 1983-04-25
Abstract
No abstract record available.
Inventors
- 👤 Prats Michael
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 11:47
CPC Classifications
E; E21; E21B; E21B43/00; E21B43/16; E21B43/24; C; C09; C09K; C09K8/00; C09K8/58; C09K8/592; E21B43/243
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
141 words
A METHOD OF RECOVERING PETROLEUM FROM A SUBTERRANEAN, PERMEABLE, OIL-BEARING FORMATION PENETRATED BY AT LEAST ONE INPUT WELL AND ONE OUTPUT WELL AT SPACED LOCATIONS COMPRISING: (A) INITIATING A COMBUSTION FRONT IN THE PORTION OF SAID FORMATION CONTIGUOUS TO SAID OUTPUT WELL; (B) INJECTING A COMBUSTION-SUPPORTING FLUID INTO SAID INPUT WELL AT A SUFFICIENT PRESSURE TO PASS THROUGH SAID PERMEABLE FORMATION TO MAINTAIN SAID COMBUSION FRONT IN SAID FORMATION; (C) CONTROLLING THE RATE OF OXIDATIVE HEATING CAUSED BY THE PASSAGE OF SAID COMBUSTION-SUPPORTING FLUID BETWEEN SAID INPUT WELL AND SAID COMBUSTION FRONT BY INJECTING AN ANTIOXIDANT THROUGH SAID INPUT WELL INTO SAID FORMATION BETWEEN SAID INPUT WELL AND SAID COMBUSTION FRONT TO PREVENT SPONTANEOUS IGNITION OF PETROLEUM AND SAID COMBUSTION-SUPPORTING FLUID BETWEEN SAID INPUT WELL AND SAID COMBUSTION FRONT; AND (D) REMOVING PETROLUEM-CONTAINING EFFLUENTS FROM SAID FORMATION IN SAID OUTPUT WELL.
Claim 2
Independent Claim
141 words
A METHOD OF RECOVERING PETROLEUM FROM A SUBTERRANEAN, PERMEABLE, OIL-BEARING FORMATION PENETRATED BY AT LEAST ONE INPUT WELL AND ONE OUTPUT WELL AT SPACED LOCATIONS COMPRISING: (A) INITIATING A COMBUSTION FRONT IN THE PORTION OF SAID FORMATION CONTIGUOUS TO SAID OUTPUT WELL; (B) INJECTING A COMBUSTION-SUPPORTING FLUID INTO SAID INPUT WELL AT A SUFFICIENT PRESSURE TO PASS THROUGH SAID PERMEABLE FORMATION TO MAINTAIN SAID COMBUSION FRONT IN SAID FORMATION; (C) CONTROLLING THE RATE OF OXIDATIVE HEATING CAUSED BY THE PASSAGE OF SAID COMBUSTION-SUPPORTING FLUID BETWEEN SAID INPUT WELL AND SAID COMBUSTION FRONT BY INJECTING AN ANTIOXIDANT THROUGH SAID INPUT WELL INTO SAID FORMATION BETWEEN SAID INPUT WELL AND SAID COMBUSTION FRONT TO PREVENT SPONTANEOUS IGNITION OF PETROLEUM AND SAID COMBUSTION-SUPPORTING FLUID BETWEEN SAID INPUT WELL AND SAID COMBUSTION FRONT; AND (D) REMOVING PETROLUEM-CONTAINING EFFLUENTS FROM SAID FORMATION IN SAID OUTPUT WELL.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1968-12-06 | 1969-06-07 | 1969-12-07 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1972-12-06 | 1973-06-07 | 1973-12-07 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1976-12-06 | 1977-06-07 | 1977-12-07 | $7700.00 | Window Closed / Lapsed |