Patent US2875142A successfully refreshed from Google Patents.
US2875142A
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Method and apparatus for cathodic protection of wells
Assignee: ConocoPhillips Co
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Filing: 1955-06-02
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Granted: 1959-02-24
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Expires: 1975-06-02
Abstract
No abstract record available.
Inventors
- 👤 James E Landers
- 👤 John D Sudbury
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 09:55
CPC Classifications
E; E21; E21B; E21B41/00; E21B41/02; C; C23; C23F; C23F13/00; C23F13/02; C23F13/04; C23F13/06; C23F2213/00; C23F2213/30; C23F2213/32
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
78 words
IN THE PROCESS OF CATHODICALLY PROTECTING THE CASING IN AN ENCASED WELL IN WHICH THE SURFACE PIPE EXTENDS DOWNWARDLY FOR ONLY A PORTION OF THE DEPTH OF THE WELL AND IN WHICH THE CASING IS MAINTAINED CATHODIC WITH RERESPECT TO A PROTECTIVE ANODE BURIED IN THE GROUND AND SPACED FROM THE WELL STRUCTURE, THE STEP COMPRISING CONNECTING A DIRECT CURRENT SOURCE BETWEEN SAID ANODE AND A POINT ON THE CASING ADJACENT TO THE BOTTOM OF THE SURFACE PIPE.
Claim 2
Dependent Claim
78 words
IN THE PROCESS OF CATHODICALLY PROTECTING THE CASING IN AN ENCASED WELL IN WHICH THE SURFACE PIPE EXTENDS DOWNWARDLY FOR ONLY A PORTION OF THE DEPTH OF THE WELL AND IN WHICH THE CASING IS MAINTAINED CATHODIC WITH RERESPECT TO A PROTECTIVE ANODE BURIED IN THE GROUND AND SPACED FROM THE WELL STRUCTURE, THE STEP COMPRISING CONNECTING A DIRECT CURRENT SOURCE BETWEEN SAID ANODE AND A POINT ON THE CASING ADJACENT TO THE BOTTOM OF THE SURFACE PIPE.
Claim 3
Dependent Claim
70 words
IN THE PROCESS OF CATHODICALLY PROTECTING THE CASING IN AN ENCASED WELL IN WHICH THE SURFACE PIPE EXTENDS DOWNWARDLY FOR ONLY A PORTION OF THE DEPTH OF THE WELL AND IN WHICH THE CASING IS MAINTAINED CATHODIC WITH RESPECT TO A PROTECTIVE ANODE BURIED IN THE GROUND AND SPACED FROM THE WELL STRUCTURE, THE STEP COMPRISING MAINTAINING AN ELECTRICAL INSULATOR BETWEEN THE TOP OF SAID SURFACE PIPE AND THE CASING.
Claim 4
Dependent Claim
70 words
IN THE PROCESS OF CATHODICALLY PROTECTING THE CASING IN AN ENCASED WELL IN WHICH THE SURFACE PIPE EXTENDS DOWNWARDLY FOR ONLY A PORTION OF THE DEPTH OF THE WELL AND IN WHICH THE CASING IS MAINTAINED CATHODIC WITH RESPECT TO A PROTECTIVE ANODE BURIED IN THE GROUND AND SPACED FROM THE WELL STRUCTURE, THE STEP COMPRISING MAINTAINING AN ELECTRICAL INSULATOR BETWEEN THE TOP OF SAID SURFACE PIPE AND THE CASING.
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) | 1962-02-23 | 1962-08-25 | 1963-02-24 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1966-02-23 | 1966-08-25 | 1967-02-24 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1970-02-23 | 1970-08-25 | 1971-02-24 | $7700.00 | Window Closed / Lapsed |