Well control apparatus
US5193619A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Oct 8, 1991 |
| Grant date | Mar 16, 1993 |
| Priority date | — |
| Expiry date | Oct 8, 2011 |
Classification
- Technology area (CPC E)Fixed Constructions
- CPC primaryE21B34/103
- WIPO fieldCivil engineering
- WIPO sectorOther fields
Abstract
Apparatus for the venting and isolation of an oil well test tool drill string comprises reference pressure gas release apparatus having two spaced pistons (7, 11) located at opposite ends of the reference gas chamber (10) and blocking both a gas vent (17) to annulus and a hydraulic liquid passageway (22) extending further up the test string, the pistons being held together by a shear pin (13) until the application of a predetermined higher pressure across those pistons causes the pin to shear, allowing sequential movement of the two pistons toward each other, firstly opening the gas vent to annulus, and secondly opening the passageway (22) to a chamber (24) of hydraulic liquid. The hydraulic liquid pressure within this passageway then causes actuation of ball valve apparatus for isolating the upper section of tubing, which in turn enables transfer of hydraulic pressure to apparatus for venting the contents of the tubing to annulus.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.