Means and method of drilling wells
US3965996A · kind A · utility
Inventor
Key dates
| Filing date | Mar 20, 1975 |
| Grant date | Jun 29, 1976 |
| Priority date | — |
| Expiry date | Mar 20, 1995 |
Classification
- Technology area (CPC E)Fixed Constructions
- CPC primaryE21B10/66
- WIPO fieldCivil engineering
- WIPO sectorOther fields
Abstract
A means and method of drilling wells wherein the casing and tubing string are rotated with minimum interruption and are moved downwardly simultaneously. A bit assembly, capable of cutting a bore larger than the casing, is lowered and raised through the drill string, the bit assembly being pivotable between a position in which the transverse axis is in alignment with the drill string bore for movement therein and a drilling position in which its longitudinal axis is transverse to the axis of the drill string and surrounding casing and extends radially beyond the casing for drilling operation; the lower end of the drill string and bit assembly having interlocking parts to transmit rotational force from the drill string to the bit assembly.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.