Apparatus and method for rotating a portion of a drill string
US6446737B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | Sep 13, 2000 |
| Grant date | Sep 10, 2002 |
| Priority date | — |
| Expiry date | Sep 13, 2020 |
Classification
- Technology area (CPC E)Fixed Constructions
- CPC primaryE21B7/068
- WIPO fieldCivil engineering
- WIPO sectorOther fields
Abstract
The present invention provides an apparatus and method for partially rotating a drill string. The drill string of the present invention comprises upper and lower sections wherein the lower section rotates relative to the upper section of the drill string from the surface at the injector head. The upper and lower sections of the drill string can comprise coiled tubing, jointed tubing or a combination of coiled and jointed tubing. The lower section of the drill string comprises a bottom hole assembly (BHA), which comprises a drill bit and downhole drilling motor. A rotational device is positioned within the drill string in order to rotate the lower section. Upon activation of the rotational device, the lower section of the drill string will be exposed to a continuous rotation. By partially rotating the lower section of the drill string, static friction forces are overcome, the probability of differential sticking of the drill string is reduced and the cuttings produced during drilling are prevented from settling on the bottom (low side) of the wellbore, thereby maintaining a clean wellbore by dragging the cuttings back into the main fluid path.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.