Dual drill string orienting apparatus and method
US3955622A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Jun 9, 1975 |
| Grant date | May 11, 1976 |
| Priority date | — |
| Expiry date | Jun 9, 1995 |
Classification
- Technology area (CPC E)Fixed Constructions
- CPC primaryE21B33/064
- WIPO fieldCivil engineering
- WIPO sectorOther fields
Abstract
Apparatus and method for orienting a pair of drill strings or the like in a predetermined manner in the center of a bore through a blowout preventer. The drill strings extend from a vessel floating on the surface of a body of water down through the preventer into a subsea wellhead installation. A first pair of opposed rams are actuated to move the drill strings into a predetermined central zone of the bore through the blowout preventer. These first rams operate under a predetermined maximum compressive force of the rams on the drill strings. Above this force, a second pair of opposed rams are activated to move the drill strings out of the predetermined central zone and into a final centrally oriented zone in the bore through the blowout preventer regardless of the position of the drill strings in the central zone. In this manner, the closing off of the drill strings with respect to the wellhead is facilitated since a proper orientation of the drill strings in the bore through the blowout preventer is provided prior to actuating the blowout preventer.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.