Safety valve closure system
US5526883A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Oct 13, 1994 |
| Grant date | Jun 18, 1996 |
| Priority date | — |
| Expiry date | Oct 13, 2014 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10T137/777
- WIPO fieldCivil engineering
- WIPO sectorOther fields
Abstract
Apparatus and method of controlling a surface safety valve and a subsurface safety valve in a producing hydrocarbons well, comprising: providing a self contained control circuitry including a reservoir for a hydraulic fluid; sensing a drop below a pre-established level of pressure in a flowline distal to the surface safety valve and a drop below a pre-established level of pressure in a portion of a hydraulic circuit fluidly connected to a subsurface safety valve proximal to the subsurface safety valve, and responsive to sensing a drop of the pressure in either the flowline or the circuitry proximal to the subsurface valve: first draining fluid to the reservoir from a portion of the circuitry means hydraulically maintaining the surface safety valve open, then after a first time delay sufficient for closure of the surface safety valve, secondly draining fluid to the reservoir from a portion of the circuitry means hydraulically maintaining the subsurface safety valve open, and then after a second time delay sufficient for closure of the subsurface safety valve, thirdly isolating the subsurface safety valve at least from the portion of the circuitry means proximal to a subsurface safet…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.