Selective hydraulic lock-out well safety valve and method
US5167284A · kind A · utility
35Cited by
6References
15Claims
0Family size
Assignee
Inventor
Key dates
| Filing date | Jul 18, 1991 |
| Grant date | Dec 1, 1992 |
| Priority date | — |
| Expiry date | Jul 18, 2011 |
Classification
- Technology area (CPC E)Fixed Constructions
- CPC primaryE21B2200/05
- WIPO fieldCivil engineering
- WIPO sectorOther fields
Abstract
A hydraulically actuated subsurface well safety valve having a first hydraulic piston and cylinder assembly for normally actuating a flow tube and controlling the opening and closing of the valve. A second lock-out piston and cylinder assembly is provided for holding the valve in the open position and a hydraulically actuated release mechanism engages the lock-out for releasing the lock-out and allowing the valve to close. A releasable and engagable latch mechanism in the second assembly releasably holds the second assembly inactive but can be overcome and reengaged for multiple operations.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.