Global Patent Index - EP 0392544 A3

EP 0392544 A3 19920408 - DRILLING TOOL

Title (en)

DRILLING TOOL

Publication

EP 0392544 A3 19920408 (DE)

Application

EP 90107054 A 19900412

Priority

DE 3912067 A 19890413

Abstract (en)

[origin: EP0392544A2] The drilling tool comprises a tubular outer housing (1) which, via connection means, can be connected at its top end to a drill-pipe string and at its bottom end to a drill bit (2), a pilot drilling unit (3) which, by means of a catch device (4), can be drawn up out of the outer housing (1) and can be put down into the outer housing (1) and is also axially displaceable in the latter during the drilling operation, and a deep-hole motor (16) operated by drilling fluid. The pilot drilling unit (3) is supported in longitudinal guides (18) in such a way as to non-rotatable relative to these longitudinal guides (18) but axially displaceable inside the outer housing (1), has reaction surfaces (5) which can be acted upon by the pressure of the drilling fluid to produce an axial feed force acting on the pilot drilling unit (3) in the bottom direction, and has a rotary body which can be rotationally driven by the deep-hole motor (16) and in turn carries a rotary boring bit (10). In this arrangement, the outer housing (1) forms the stator of the deep-hole motor designed as a turbine (16), and a tubular inner housing (17) rotatably supported in the outer housing (1) forms the rotor of the turbine (16), and the longitudinal guides (18) supporting the pilot drilling unit in operation are provided in the inner housing (17).

IPC 1-7

E21B 4/02; E21B 25/04

IPC 8 full level

E21B 4/02 (2006.01); E21B 25/04 (2006.01)

CPC (source: EP US)

E21B 4/02 (2013.01 - EP US); E21B 25/04 (2013.01 - EP US)

Citation (search report)

Designated contracting state (EPC)

FR GB

DOCDB simple family (publication)

EP 0392544 A2 19901017; EP 0392544 A3 19920408; EP 0392544 B1 19940720; CA 2014570 A1 19901013; DE 3912067 C1 19900906; US 5038873 A 19910813

DOCDB simple family (application)

EP 90107054 A 19900412; CA 2014570 A 19900412; DE 3912067 A 19890413; US 52370290 A 19900412