Method and apparatus for multi-zone casing perforation
US4790383A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Oct 1, 1987 |
| Grant date | Dec 13, 1988 |
| Priority date | — |
| Expiry date | Oct 1, 2007 |
Classification
- Technology area (CPC E)Fixed Constructions
- CPC primaryE21B43/116
- WIPO fieldCivil engineering
- WIPO sectorOther fields
Abstract
A perforating-gun spacer used to position a plurality of guns to perforate a multizone reservoir is formed of a plurality of telescoping sections which are held in an extended position by tapered pins. A slidable piston maintains the pins in engaged position. When the perforating guns are fired, the resultant pressure pulse in the wellbore fluid moves the piston upwardly out of engagement with the restraining pins which then disengage permitting the telescoping sections to collapse when the expended tool is dropped into the bottom of the wellbore. This avoids partial or complte blockage of the lowermost production zone by the upper portion of the perforating gun string.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.