Hydraulic jar and an overpressure relief mechanism therefor
US7814995B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Mar 19, 2008 |
| Grant date | Oct 19, 2010 |
| Priority date | — |
| Expiry date | Jun 27, 2028 |
Classification
- Technology area (CPC E)Fixed Constructions
- CPC primaryE21B31/1135
- WIPO fieldCivil engineering
- WIPO sectorOther fields
Abstract
A hydraulic jar for a drilling assembly is disclosed. In some embodiments, the hydraulic jar includes a tubular housing, a mandrel disposed in the housing, an annulus between the mandrel and the housing, and a pressure relief mechanism disposed in the annulus. The pressure relief mechanism generally divides the annulus into first and second portions. The pressure relief mechanism includes first and second annular members in engagement with one another when the pressure in the second annulus portion is less than a predetermined value and a fluid flow path between the first and second annulus portions. The fluid flow path has a first size when the pressure in the second annulus portion is less than the predetermined value, and a second size that is larger than the first size when the pressure in the second annulus portion becomes equal to or greater than the predetermined value.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.