Method of drilling deviated wellbores
US4719977A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Dec 22, 1986 |
| Grant date | Jan 19, 1988 |
| Priority date | — |
| Expiry date | Dec 22, 2006 |
Classification
- Technology area (CPC E)Fixed Constructions
- CPC primaryE21B7/068
- WIPO fieldCivil engineering
- WIPO sectorOther fields
Abstract
Directional drilling is carried out with a rotary drilling tool having a drill string, a drill bit, a drill motor for rotating the drill bit independently of the drill string, an extension sub having both axially contracted and axially extended positions for providing weight to the drill bit when moving from a contracted to an extended position so as to effect a drilling stroke by the drill bit into the wellbore bottom when drilling with the drill bit independently of rotation of the drill string and a relaxation device for removing any excess weight on the drill bit that would otherwise be detrimental to the direction drilling of a deviated wellbore.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.