Releasing tool
US5577566A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Aug 9, 1995 |
| Grant date | Nov 26, 1996 |
| Priority date | — |
| Expiry date | Aug 9, 2015 |
Classification
- Technology area (CPC E)Fixed Constructions
- CPC primaryE21B21/01
- WIPO fieldCivil engineering
- WIPO sectorOther fields
Abstract
A new tool has been developed for, in one aspect, facilitating release of a tubular string coupled between a travelling block and elevators with insufficient clearance to release elevator slips in order to remove the tubular. In one aspect the releasing tool is effectively shortened permitting release of the elevators. Such shortening is effected by releasing an expansion sub and piston within the tool for relative movement with respect to other parts of the tool. Initially the expansion sub and piston are held in place by fluid in a first chamber. Movement of fluid from the first chamber and movement of fluid into a second chamber housing the piston results in piston movement (and movement of the expansion sub which is secured to the piston) to effectively shorten the tool. In one aspect the fluid moves in a closed loop between the chambers and no fluid is expelled to the environment. In another aspect only one fluid chamber is used.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.