Patent US3741297A successfully refreshed from Google Patents.
US3741297A
Expired / Lapsed
US
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Subsidence wellhead assembly and method
Assignee: Cooper Industries LLC
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Filing: 1971-02-17
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Granted: 1973-06-26
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Expires: 1991-02-17
Abstract
Abstract Production casing is retensioned with hydraulic jacks placed between tubing head flange and packoff flange connected to casing head flange, the production casing being screwed into tubing head and also supported in casing head by slip type casing hanger whose slips are spring biased downwardly. The packoff flange has a packing gland accessible from the top for seal replacement. The jacks are of the spring retract and fluid expand type adapted for actuation by a manual pump. A fluid pressure gage is calibrated to read in pounds of casing tension and is marked to show maximum permissible load on jacks.
Inventors
- 👤 A Drouin
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 10:18
CPC Classifications
E; E21; E21B; E21B33/00; E21B33/02; E21B33/03; E21B33/04; E21B33/0415
Claims Analysis
Total Claims: 3
Claim 1
Independent Claim
137 words
Wellhead including an annular member having side port means, upper and lower connection means respectively at the upper and lower ends of said annular member, said annular member being adapted to support a pipe disposed coaxially therein, force transmitting means about the lower end of said annular member for engaging and transmitting force to said wellhead from hydraulic jack means disposed therebelow, said force transmitting means including lower flange means extending laterally from said annular member radially beyond said side port means, said lower connection means including a threaded socket at the lower end of said annular member, said lower connection means further including a slip on and weld nipple screwed into said thread socket, said nipple having an unthreaded belled out socket at its lower end adapted to slip over and be welded to another pipe.
Claim 2
Dependent Claim
137 words
Wellhead including an annular member having side port means, upper and lower connection means respectively at the upper and lower ends of said annular member, said annular member being adapted to support a pipe disposed coaxially therein, force transmitting means about the lower end of said annular member for engaging and transmitting force to said wellhead from hydraulic jack means disposed therebelow, said force transmitting means including lower flange means extending laterally from said annular member radially beyond said side port means, said lower connection means including a threaded socket at the lower end of said annular member, said lower connection means further including a slip on and weld nipple screwed into said thread socket, said nipple having an unthreaded belled out socket at its lower end adapted to slip over and be welded to another pipe.
Claim 3
Dependent Claim
32 words
Wellhead according to claim 1, said upper connection means including upper flange means to receive lock screws, said lower flange means extending laterally at least as far as said upper flange means.
References Cited (Backward Citations)
No citation records indexed.
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1976-06-25 | 1976-12-25 | 1977-06-26 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-06-25 | 1980-12-25 | 1981-06-26 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-06-25 | 1984-12-25 | 1985-06-26 | $7700.00 | Window Closed / Lapsed |