Apparatus and method for retrieving an object from a well bore, and method for making a tool for retrieving objects from a well bore
US5409065A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | May 18, 1994 |
| Grant date | Apr 25, 1995 |
| Priority date | — |
| Expiry date | May 18, 2014 |
Classification
- Technology area (CPC E)Fixed Constructions
- CPC primaryE21B31/18
- WIPO fieldCivil engineering
- WIPO sectorOther fields
Abstract
An apparatus for retrieving objects from well bores includes an uppermost segment having an internally threaded opening extending upwardly from a bottom end of the uppermost segment to a first location above the bottom end. One or more additional segments are provided. Each of the additional segments have top and bottom ends and are removably attachable, at a top end of each additional segment, to a bottom end of one of an upper one of the additional segments and the uppermost segment. Each of the additional segments have a tapered, internally threaded opening extending between the top end and the bottom end of the additional segments. A top end of the uppermost segment is secured to a bottom end of a rotatable down-hole drill rod and is lowered down around and rotated relative to an object to be retrieved such that threads on the tapered, internally threaded opening engage with the object. A method for using the apparatus and a method for making a retrieving tool are also disclosed.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.