Extension drilling system
US6145603A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jun 11, 1998 |
| Grant date | Nov 14, 2000 |
| Priority date | — |
| Expiry date | Jun 11, 2018 |
Classification
- Technology area (CPC E)Fixed Constructions
- CPC primaryE21B19/16
- WIPO fieldCivil engineering
- WIPO sectorOther fields
Abstract
An extension drilling system for use with a semiautomatic drilling rig. The drilling system includes a plurality of extension rods constituting a drill rod string and having cooperating male and female threaded couplings therebetween, and being right-hand rope threaded couplings. A reversible drive chuck of a drilling rig drives (either directly, or via an adaptor), the outside of the female threaded end of an associated extension rod. A gripper grips one of the extension rods to hold the drill rod string stationary when the chuck is driven in reverse. The gripper is located such that only one threaded coupling is disposed between the chuck and grippers and to ensure that when the chuck is rotated in reverse, only the desired coupling is uncoupled. The drill rods have axial passages therethrough in communication with each other and through which flushing fluid is delivered to an associated drill bit and a non-return valve is incorporated in the passage through at least one of the drill rods. A socket of the drive chuck (or adaptor) is configured to automatically lock the drill rod in the socket in response to rotation of the drive chuck.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.