Subsurface safety valve apparatus
US4014386A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Apr 23, 1976 |
| Grant date | Mar 29, 1977 |
| Priority date | — |
| Expiry date | Apr 23, 1996 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10T137/2934
- WIPO fieldCivil engineering
- WIPO sectorOther fields
Abstract
In accordance with an illustrative embodiment of the present invention, a subsurface safety valve assembly includes a dome precharged with a set reference pressure that tends to close the valve, and means responsive to both ambient pressure and to the pressure of a control fluid for holding the valve open under normal conditions, a decrease in either control fluid pressure or tubing pressure, or both, enabling the dome pressure to cause the valve to automatically close and shut-in the well. The valve does not employ a coil spring to cause closure, which permits installation at great depths in a well, and a narrow spread between valve opening and closing pressures.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.