Rotating blowout preventer and method
US5588491A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Aug 10, 1995 |
| Grant date | Dec 31, 1996 |
| Priority date | — |
| Expiry date | Aug 10, 2015 |
Classification
- Technology area (CPC E)Fixed Constructions
- CPC primaryE21B33/085
- WIPO fieldCivil engineering
- WIPO sectorOther fields
Abstract
The rotatable blowout preventer 10 comprises a stationary outer housing 12 and a rotatable inner housing 38 having a curved surface 42 thereon defining a portion of a sphere. An annular packer assembly 46 includes spherical packer elements for sliding engagement with the curved surface of the inner housing such that a packer assembly may seal against various sized tubulars. A lower rotary seal 98 between a piston 56 and the outer housing 12 is exposed to the differential between pressurized hydraulic fluid and the well pressure within a lower end of the bore 32 within the outer housing. A flow restriction member 114 between the rotatable inner housing and the outer housing reduces fluid pressure downstream from the flow restriction to less than 40% of the upstream pressure. The upper rotary seal 120 is open to atmospheric pressure and is subjected to this reduced pressure. Improved techniques are provided for passing hydraulic fluid through the blowout preventer for both closing and opening the sealing assembly 46.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.