Lock-down releasing spear assembly
US4706745A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Dec 15, 1986 |
| Grant date | Nov 17, 1987 |
| Priority date | — |
| Expiry date | Dec 15, 2006 |
Classification
- Technology area (CPC E)Fixed Constructions
- CPC primaryE21B31/20
- WIPO fieldCivil engineering
- WIPO sectorOther fields
Abstract
An apparatus for engaging a tubular member with a tension type spear in which the spear is locked to the tubular member so that it is not released when compressive or other non-tension loads are applied to it. The present invention locks the spear to the tubular member through abutment of a transfer assembly connected to the spear supporting mandrel after the spear has been set within the tubular member. The abutment of the transfer assembly and the tubular member lock the spear within the tubular member under tension so that compressive or other non-tension loads on the supporting pipe string will not affect the grip of the spear.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.