Directional drilling apparatus
US7013994B2 · kind B2 · utility
Assignee
Inventor
Key dates
| Filing date | Jan 23, 2002 |
| Grant date | Mar 21, 2006 |
| Priority date | — |
| Expiry date | Aug 28, 2022 |
Classification
- Technology area (CPC E)Fixed Constructions
- CPC primaryE21B7/062
- WIPO fieldCivil engineering
- WIPO sectorOther fields
Abstract
Directional drilling apparatus for use in drilling a deviated bore comprises a mandrel for mounting to a drill string and having a main axis. A non-rotating mass is rotatably mounted on the mandrel and has a center-of-gravity spaced from the mandrel axis. The apparatus further comprises an offsetting arrangement including a non-rotating offsetting portion rotatably mounted on the mandrel, coupled to the mass, and having an outer profile defining an offset relative to the mandrel axis, and a bearing portion rotatably mounted on the offsetting portion. In use, the apparatus is run into an inclined bore on a string, and the offsetting portion is oriented relative to the mass. When the string is rotated the mass tends towards an orientation with its center-of-gravity positioned towards the low side of the bore and thus tends to maintain the offsetting portion in a desired relative orientation in the bore, the bearing portion rotationally isolating the offsetting portion from the bore wall.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.