Casing perforation method and apparatus
US4113016A · kind A · utility
Inventor
Key dates
| Filing date | Sep 26, 1977 |
| Grant date | Sep 12, 1978 |
| Priority date | — |
| Expiry date | Sep 26, 1997 |
Classification
- Technology area (CPC E)Fixed Constructions
- CPC primaryE21B43/119
- WIPO fieldCivil engineering
- WIPO sectorOther fields
Abstract
Method and apparatus for effecting perforation of a well casing with a casing gun while maintaining pressure in the well bore at a lower level than the pressure in the surrounding reservoir at the point of perforation. Before production tubing is run into the well, the casing gun is deposited in the bore below the desired production level. After the tubing is installed, borehole pressure is reduced to the desired level by swabbing the tubing and an automatic coupling and decoupling pickup tool is lowered on a wireline through the tubing and attached, mechanically and electrically, to the casing gun. The casing gun is then raised to the production level, as measured by locating the casing collars. Whe the gun is properly located, it is activated through an electrical cable carried along with the wireline. The casing gun perforates the well casing and surrounding formation, and is then decoupled from the wireline to be left in the well.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.