Title (en)

DRILLING DEVICE

Publication

EP 0352427 A3 19910515 (DE)

Application

EP 89109334 A 19890524

Priority

DE 3825225 A 19880725

Abstract (en)

[origin: US4969528A] The present invention comprises an improved method and apparatus for taking core samples, wherein a core drilling assembly driven by a downhole fluid motor is retrievably housed within a drilling tool of larger diameter, and wherein a plurality of cores may be cut and retrieved to the surface by withdrawal of the core drilling assembly by including an extender in the core drilling assembly each time it is brought to the surface and returned to the drilling tool, and sequentially cutting another core without postdrilling the previously cored formation section. The extenders may be included either above or below the motor used to drive the core drilling assembly, and are preferably of tubular configuration with screw-threaded connectors at their ends for rapid insertion in and removal from the core drilling assembly.

IPC 1-7

E21B 25/04; E21B 4/02

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)

• [Y] US 3485310 A 19691223 - MILOSEVICH VINCENT
• [YD] DE 3701914 C1 19880519 - EASTMAN CHRISTENSEN CO
• [AP] DE 3729138 A1 19890420 - BERGBAU BOHRGESELLSCHAFT RHEIN [DE]

Designated contracting state (EPC)

BE FR GB NL

DOCDB simple family (publication)

US 4969528 A 19901113; CA 1320944 C 19930803; DE 3825225 A1 19900201; DE 3825225 C2 19910523; EP 0352427 A2 19900131; EP 0352427 A3 19910515; EP 0352427 B1 19940302

DOCDB simple family (application)

US 38148989 A 19890718; CA 606476 A 19890724; DE 3825225 A 19880725; EP 89109334 A 19890524