Well locking device
US4254829A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Sep 24, 1979 |
| Grant date | Mar 10, 1981 |
| Priority date | — |
| Expiry date | Sep 24, 1999 |
Classification
- Technology area (CPC E)Fixed Constructions
- CPC primaryE21B23/02
- WIPO fieldCivil engineering
- WIPO sectorOther fields
Abstract
In a well lock and a locking nipple for use in a tubing in a well in which the locking nipple includes first and second recesses and a stop shoulder and the well lock includes a locking housing carrying first and second locking dogs, seal means on the exterior of the housing for sealing with the nipple, a resiliently outwardly urged locator having a shoulder for engaging the stop shoulder, a mandrel telescopically positioned in the housing, a locking shoulder on the mandrel locking the first locking dogs in the first recess and means on the mandrel engaging the second locking means for preventing unlocking of the first locking dogs if pressure is applied to the seal to move the housing upwardly, the improvement in which the distance between the bottom of the first recess and the locking shoulder is greater than the distance between the bottom of the first locking dogs and the locator shoulder whereby the first locking dogs lock the device against upwardly and downwardly forces and the locator is retracted out of contact with the stop shoulder.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.