Wellbore apparatus including a rathole pressure balanced-differential pressure firing system
US5191933A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | May 1, 1992 |
| Grant date | Mar 9, 1993 |
| Priority date | — |
| Expiry date | May 1, 2012 |
Classification
- Technology area (CPC E)Fixed Constructions
- CPC primaryE21B34/103
- WIPO fieldCivil engineering
- WIPO sectorOther fields
Abstract
A well apparatus adapted to be disposed in a wellbore includes a perforating apparatus and a packer adapted to set and isolate an annulus above the packer from a rathole annulus below the packer, the perforating apparatus including a new and novel rathole differential pressure balanced firing system where the firing system includes a ball release sleeve holding a firing piston, means for initially opening a top end and a bottom end of the ball release sleeve to the rathole annulus below the packer; and a plurality of sequentially operable hydraulic systems, the top end of the ball release sleeve being initially open to the rathole annulus below the packer but being subsequently closed to the rathole annulus below the packer and then reopened to the annulus above the packer when the packer is set. When the top end of the ball release sleeve is opened relative to the annulus above the packer and the significant pressure is applied to the annulus above the packer, the ball release sleeve releases the firing piston; as a result, since the firing piston is released, the firing piston drops and impacts a primer, the impact of the firing piston on the primer detonating the perforating app…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.