Latch assembly for well tools
US4722393A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Apr 29, 1987 |
| Grant date | Feb 2, 1988 |
| Priority date | — |
| Expiry date | Apr 29, 2007 |
Classification
- Technology area (CPC E)Fixed Constructions
- CPC primaryE21B34/16
- WIPO fieldCivil engineering
- WIPO sectorOther fields
Abstract
A minimum backlash latch assembly for releasably locking a well tool such as a pilot valve in a bore such as in a side pocket mandrel of a well flow conductor. Also disclosed is a pilot valve system for a subsurface safety valve operated by control fluid pressure from the surface including a pilot valve connected with the control fluid line to the subsurface safety valve and into the well production string immediately above the safety valve to bypass the control fluid pressure directly into the tubing string and dump the control fluid pressure from the subsurface safety valve into the tubing string directly above the valve to minimize the time delay between control fluid pressure reduction and the safety valve closure. Three embodiments of the pilot valve are disclosed. One embodiment is operable by electrical energy from the surface. The other embodiments are operable by acoustic energy and radio waves, respectively.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.