EP 0469317 A3 19930414 - METHOD AND DEVICE FOR MODIFYING THE WEIGHT ON AN EARTH FRILL BIT

Title (en)

METHOD AND DEVICE FOR MODIFYING THE WEIGHT ON AN EARTH FRILL BIT

Publication

EP 0469317 A3 19930414 (DE)

Application

EP 91110976 A 19910703

Priority

DE 4024107 A 19900730

Abstract (en)

[origin: EP0469317A2] In a method and a drilling device for sinking a bore in underground rock formations, a drilling tool (1), provided at the end face with a rotary drill bit (4) and axially displaceable in parallel relative to a drill-pipe string at least in certain areas via a telescopic connection (14; 15), is supplied with drilling fluid through the drill-pipe string (3), and a hydraulic applied pressure of the drill bit is derived from the drilling fluid. In the process, the applied pressure of the drill bit is set as a function of drilling parameters, changing during the sinking, by changing in a controlled manner at the surface the hydraulic parameters relevant to the hydraulic derivation of the applied pressure. <IMAGE>

IPC 1-7

E21B 44/00; E21B 17/07; E21B 7/06

IPC 8 full level

E21B 7/06 (2006.01); E21B 17/07 (2006.01); E21B 21/08 (2006.01); E21B 44/00 (2006.01)

CPC (source: EP US)

E21B 7/06 (2013.01 - EP US); E21B 7/068 (2013.01 - EP US); E21B 17/07 (2013.01 - EP US); E21B 44/005 (2013.01 - EP US)

Citation (search report)

[X] GB 732423 A 19550622 - BATAAFSCHE PETROLEUM
[X] US 3233689 A 19660208 - FRANK WHITTLE
[X] US 2937007 A 19600517 - FRANK WHITTLE
[X] GB 857173 A 19601229 - JERSEY PROD RES CO
[X] US 3497019 A 19700224 - ORTLOFF JOHN E
[X] US 4212359 A 19800715 - ADCOCK GERALD L [US]
[XD] US 4440241 A 19840403 - ANDERS EDWARD O [US]
[A] US 3039543 A 19620619 - GERHARD LOOCKE
[A] US 3785202 A 19740115 - KELSEAUX R, et al
[X] US 3815692 A 19740611 - VARLEY R
[X] US 3407886 A 19681029 - BENNETT JOHN D
[X] CH 330386 A 19580615 - WITTGENSTEIN GERARD F [CH]
[A] US 3517760 A 19700630 - KEHRBERGER ACHIM
[A] GB 2032494 A 19800508 - SALZGITTER MASCHINEN AG
[A] US 3827512 A 19740806 - EDMOND T

Designated contracting state (EPC)

BE DE FR GB NL

DOCDB simple family (publication)

EP 0469317 A2 19920205; EP 0469317 A3 19930414; EP 0469317 B1 19971229; CA 2047555 A1 19920131; CA 2047555 C 20020326; DE 4024107 C1 19920416; DE 59108909 D1 19980205; NO 302773 B1 19980420; NO 912712 D0 19910710; NO 912712 L 19920131; US 5205364 A 19930427

DOCDB simple family (application)

EP 91110976 A 19910703; CA 2047555 A 19910722; DE 4024107 A 19900730; DE 59108909 T 19910703; NO 912712 A 19910710; US 73777191 A 19910730