Hydraulically activated firing head for well perforating guns
US4880056A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jul 11, 1988 |
| Grant date | Nov 14, 1989 |
| Priority date | — |
| Expiry date | Jul 11, 2008 |
Classification
- Technology area (CPC E)Fixed Constructions
- CPC primaryE21B43/1193
- WIPO fieldCivil engineering
- WIPO sectorOther fields
Abstract
A separable fluid pressure activated firing mehanism for a perforating gun comprises a pressure-operated tubing valve, a packer, and a tubular housing assembly defining a plurality of fluid pressure chambers therein. The first chamber contains a light density, clean, compressible fluid which is subject to well annulus pressure above the packer to provide a reference pressure. A second chamber sealably mounts a piston-type firing pin, which is normally secured by a locked latch in an elevated position above a detonatable primer and the lower portion of said firing pin is exposed to the reference pressure. The latch is unlocked through the application of a predetermined annulus pressure above the packer to a locking piston which moves to unlock the latch and trap the reference pressure in the first chamber. A further increase in said annulus pressure opens the tubing valve. A still further increase in said annulus pressure releases the firing pin from the latch and drives the firing pin downwardly to detonate the primer. Additional features of the disclosure are the provision of a cross-over tool between the packer and the tubular housing assembly to permit underbalance perforating, …
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.