Rotary jar
US5669458A · kind A · utility
Inventor
Key dates
| Filing date | Mar 1, 1996 |
| Grant date | Sep 23, 1997 |
| Priority date | — |
| Expiry date | Mar 1, 2016 |
Classification
- Technology area (CPC E)Fixed Constructions
- CPC primaryE21B31/107
- WIPO fieldCivil engineering
- WIPO sectorOther fields
Abstract
A rotary jar is described that is part of a drill string and includes a mandrel and an anvil that move longitudinally in opposite directions to deliver a sharp upward or downward blow that is transmitted to a fish, which may be a separate tool or a portion of the drill string that is stuck in the well bore in an effort to free the fish or the stuck portion of the drill pipe. The mandrel carries rollers that move through longitudinally extending grooves when the jars are tripped. In the jars of this invention, the grooves follow a serpentine path to cause the mandrel to transmit a torsional force on the fish to try to rotate the fish as well as providing an upward or downward blow.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.