Subsurface safety valve
US4140153A · kind A · utility
19Cited by
1References
13Claims
0Family size
Assignee
Inventor
Key dates
| Filing date | May 6, 1977 |
| Grant date | Feb 20, 1979 |
| Priority date | — |
| Expiry date | May 6, 1997 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10T137/86936
- WIPO fieldCivil engineering
- WIPO sectorOther fields
Abstract
A surface controlled subsurface safety valve having a main valve and an equalizing valve. The equalizing valve is opened prior to the opening of the main valve. An extra control pressure force is provided to open the equalizing valve against the resistive force present due to high shut-in formation pressures. On the other hand, the safety valve can close when low subsurface pressure conditions exist at the valve. This abstract is neither intended to define the scope of the invention, which, of course, is measured by the claims, nor is it intended to be limiting in any way.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.