EP 1085166 A1 20010321 - Auger drill
Title (en)
Auger drill
Title (de)
Spiralbohrer
Title (fr)
Fleuret hélicoidal
Publication
Application
Priority
FR 9911505 A 19990915
Abstract (en)
Drilling tool with a drill bit assembly, means of rotating this assembly and a tube surrounding part of the length of the bit. Mounted over at least part of its length, the tube has means of limiting the speed of rotation of the extracted mud relative to the speed of rotation of the drill bit assembly so the rotation of the drill bit assembly allows the vertical displacement of the mud into the tube The means of limiting the relative speeds of rotation acts mechanically and comprises an internal coating on the tube to produce a friction coefficient, or a helix with the same axis as the drill bit, placed between the edge of the drill bit and the tube and fixed or driven in rotation in the opposite direction to that of the drill bit. Alternatively, the means of limiting the speed of rotation is roughnesses (protrusions) or grooves on the internal face of the tube. The drill bit assembly has a first upper drill bit whose lower end extends below the lower end of the tube by a length L and a second drill bit with the same axis as the first placed and below the first. The means of rotation are therefore a first means for the first drill bit and a second means for the second drill bit. The length L is at least one pitch of the helix of the first drill bit. The external diameter of the second drill bit is the same as that of the tube. The first and second means of rotation can drive them in opposite directions.
Abstract (fr)
L'invention concerne un outil de forage comportant un ensemble formant tarière (32, 34) de forage, des moyens de mise en rotation (38, 42) de l'ensemble formant tarière de forage et un tubage (44) entourant sur une partie de sa longueur l'ensemble formant tarière. Ledit tubage (44) comprend sur au moins une partie de sa longueur des moyens, de préférence disposés sur la partie interne (50) du tubage, pour limiter la vitesse de rotation du terrain extrait par l'ensemble formant tarière à proximité de la face interne dudit tubage par rapport à la vitesse de rotation dudit ensemble formant tarière, par quoi la rotation de l'ensemble formant tarière permet le déplacement vertical du terrain extrait à l'intérieur dudit tubage. <IMAGE>
IPC 1-7
IPC 8 full level
E21B 7/20 (2006.01)
CPC (source: EP)
E21B 7/201 (2013.01)
Citation (search report)
- [A] EP 0311363 A2 19890412 - KAWASAKI STEEL CO [JP]
- [A] EP 0699823 A1 19960306 - KOMATSU MFG CO LTD [JP]
Designated contracting state (EPC)
DE ES FR GB IT
DOCDB simple family (publication)
EP 1085166 A1 20010321; FR 2798420 A1 20010316; FR 2798420 B1 20011214
DOCDB simple family (application)
EP 00402300 A 20000817; FR 9911505 A 19990915