Well locking device and method
US4161984A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Sep 11, 1978 |
| Grant date | Jul 24, 1979 |
| Priority date | — |
| Expiry date | Sep 11, 1998 |
Classification
- Technology area (CPC E)Fixed Constructions
- CPC primaryE21B23/02
- WIPO fieldCivil engineering
- WIPO sectorOther fields
Abstract
A well locking device and method of operation including a well lock and a landing nipple for locking well equipment in the production string of oil and/or gas wells. The well lock includes two sets of locking dogs, one of which locks the well lock in the landing nipple and holds against loads either from above or below the lock. The second set of locking dogs prevents the release of the well lock from the nipple when a pressure differential exists across the lock. A locking nipple includes first and second recesses and a stop shoulder and the coacting well lock includes a housing carrying first and second locking dogs in which the vertical spacing of the first and second locking dogs is less than the vertical distance between the tops of the first and second recesses. A seal is positioned on the exterior of the well lock housing and adapted to seal in the locking nipple, and locating means are provided on the housing for engaging the stop shoulder of the nipple. The lock can be released only by moving it downwardly and then upwardly, but any pressure below the lock sufficient to lift the lock back up after being moved downwardly will not allow the lock to be released.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.