Safety system
US4469179A · kind A · utility
14Cited by
7References
3Claims
0Family size
Assignee
Inventors
Key dates
| Filing date | Dec 17, 1981 |
| Grant date | Sep 4, 1984 |
| Priority date | — |
| Expiry date | Dec 17, 2001 |
Classification
- Technology area (CPC E)Fixed Constructions
- CPC primaryE21B34/106
- WIPO fieldCivil engineering
- WIPO sectorOther fields
Abstract
A well controlled by two hydraulically operated subsurface safety valves made up in the tubing string. A first valve is mechanically locked in open position and the second valve is utilized to control flow through the string. Upon malfunction of the second valve it is locked in open position and the first valve is released from its locked open position and is utilized to control flow through the string.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.