Accelerator for fishing jar with hydrostatic assist
US4844183A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Oct 28, 1987 |
| Grant date | Jul 4, 1989 |
| Priority date | — |
| Expiry date | Oct 28, 2007 |
Classification
- Technology area (CPC E)Fixed Constructions
- CPC primaryE21B31/113
- WIPO fieldCivil engineering
- WIPO sectorOther fields
Abstract
An accelerator for a fishing jar is disclosed. The accelerator includes front, compression, rear, and air chambers. These chambers insure that the pressure of the fluid in the compression chamber is substantially independent of the temperature of the fluid and the hydrostatic pressure of the well. These chambers also insure that the high pressure seals of the compression chamber are lubricated on each side of each seal. The accelerator also insures that a threshold upward force which is proportional to the hydrostatic pressure must be applied to the drill string before the fluid in the compression chamber begins to be compressed, thereby providing an accelerator that has a higher maximum load in deep wells.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.