Unrestricted bore safety joint
US4445572A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Aug 17, 1981 |
| Grant date | May 1, 1984 |
| Priority date | — |
| Expiry date | Aug 17, 2001 |
Classification
- Technology area (CPC E)Fixed Constructions
- CPC primaryE21B17/06
- WIPO fieldCivil engineering
- WIPO sectorOther fields
Abstract
An apparatus, such as a shear-out safety joint, which is incorporated in a subterranean well tubing string for separating or severing the tubing string when subjected to excessive loads is disclosed. The shear-out safety joint is used with a safety valve and by providing a prescribed failure point will ensure that the safety valve remains intact. The apparatus includes inner and outer telescoping members which can separate when the tubing above and below the joint moves in opposite directions. A shear ring connecting the two telescoping members will shear when a predetermined load is applied. The joint also has a second releasable connecting member extending through the inner telescoping member and engaging the outer telescoping member which will support a load greater than that which can be carried by the shear ring. A longitudinally shiftable member, movable within a recess, holds the second connecting member in engagement but disengages the second connecting member when moved to a second position.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.