EP 0467642 A3 19930310 - EARTH DRILLING SYSTEM AND METHOD FOR CONTROLLING THE DIRECTION OF A BOREHOLE
Title (en)
EARTH DRILLING SYSTEM AND METHOD FOR CONTROLLING THE DIRECTION OF A BOREHOLE
Publication
Application
Priority
- GB 9015704 A 19900717
- GB 9100874 A 19910115
Abstract (en)
[origin: EP0467642A2] A steerable rotary drilling system for drilling or coring holes in subsurface formations comprises a bottom hole assembly 11 including a drill bit 13 carrying a plurality of cutting structures 16, and a mud hammer 14 which applies repeated axial impulses to the bit at a frequency greater than its frequency of rotation. Operation of the mud hammer 14 may be modulated in synchronism with rotation of the drill bit 13 and in controllable phase relation thereto. The drill bit is asymmetrically arranged, for example by an asymmetric distribution of the cutters 16, so that by appropriate selection of the phase relation the bit may be steered in a desired direction. <IMAGE>
IPC 1-7
IPC 8 full level
E21B 4/20 (2006.01); E21B 7/06 (2006.01); E21B 10/42 (2006.01); E21B 10/43 (2006.01)
CPC (source: EP US)
E21B 4/20 (2013.01 - EP); E21B 7/064 (2013.01 - EP US); E21B 7/068 (2013.01 - EP); E21B 10/43 (2013.01 - EP US)
Citation (search report)
- [X] EP 0343800 A2 19891129 - FLOWMOLE CORP [US]
- [Y] EP 0370709 A1 19900530 - INTECH INT INC [CA]
- [Y] US 4461359 A 19840724 - JONES JR EMRYS H [US], et al
- [XD] US 4637479 A 19870120 - LEISING LAWRENCE J [US]
- [APD] US 4995465 A 19910226 - BECK JEFFREY L [US], et al
- [AD] WO 9005235 A1 19900517 - NOBLE JAMES BAIN [GB]
- [A] US 4852669 A 19890801 - WALKER THOMAS A [US]
Designated contracting state (EPC)
BE DE FR GB NL
DOCDB simple family (publication)
EP 0467642 A2 19920122; EP 0467642 A3 19930310; AU 8044091 A 19920123; CA 2047316 A1 19920118; GB 2246151 A 19920122; GB 9115488 D0 19910904; NO 912794 D0 19910717; NO 912794 L 19920120
DOCDB simple family (application)
EP 91306436 A 19910716; AU 8044091 A 19910716; CA 2047316 A 19910717; GB 9115488 A 19910717; NO 912794 A 19910717