Hydraulic jars for bore hole drilling
US4081043A · kind A · utility
9Cited by
4References
14Claims
0Family size
Assignee
Inventor
Key dates
| Filing date | Jan 26, 1977 |
| Grant date | Mar 28, 1978 |
| Priority date | — |
| Expiry date | Jan 26, 1997 |
Classification
- Technology area (CPC E)Fixed Constructions
- CPC primaryE21B31/113
- WIPO fieldCivil engineering
- WIPO sectorOther fields
Abstract
Hydraulic jar apparatus to be disposed in a drilling string used in drilling a well bore or other bore hole, embodying inner and outer telescopically arranged bodies, with a hammer on the inner body adapted to strike an anvil on the outer body, the bodies being initially releasably locked or interconnected in fully telescoped or contracted relation by a locking device which can be released while the apparatus is in the bore hole before the apparatus can function as a jarring device or a bumper sub.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.