Title:
【発明の名称】岩層を水平に方向を定めて穿孔するためのドリルビット
Document Type and Number:
Japanese Patent JP3088097
Kind Code:
B2
Abstract:
The method includes the step of causing a specially-configured drill bit (102) at one end of a drill string (104) to intermittently rotate as it digs in, stops rotation until the rock fractures, and then moves after fracture in a random, orbital intermittent motion. Preferably the drill string (104) is rotated under pressure at a substantially constant rotational velocity at the other end of the drill string by a conventional directional drilling machine. A fluid (not shown) may be pumped into the drill string (104) and out the drill bit (102) to lubricate the hole and disperse cuttings.
Inventors:
David M Cox
Application Number:
JP3387298A
Publication Date:
September 18, 2000
Filing Date:
January 29, 1998
Export Citation:
Assignee:
Railhead Underground Products LLC
International Classes:
E21B7/04; E21B3/00; E21B7/06; E21B10/26; E21B10/36; E21B10/56; E21B10/60; E21B17/046; E21B47/01; (IPC1-7): E21B10/36; E21B3/00
Domestic Patent References:
| JP6336891A | ||||
| JP9125852A | ||||
| JP220789A | ||||
| JP183797A | ||||
| JP9505646A | ||||
| JP8501844A |
Attorney, Agent or Firm:
Koichiro Kato (2 outside)