Global Patent Index - EP 0065601 A1

EP 0065601 A1 19821201 - Constant bottom contact tool.

Title (en)

Constant bottom contact tool.

Title (de)

In stätigem Kontakt mit der Bohrlochsohle gehaltenes Werkzeug.

Title (fr)

Dispositif pour maintenir un contact permanent avec le fond du trou.

Publication

EP 0065601 A1 19821201 (EN)

Application

EP 81302299 A 19810522

Priority

EP 81302299 A 19810522

Abstract (en)

A drill string (11) in a well bore (10) has a mandrel (13) extending longitudinally thereof adjacent the lower end (14) of the drill string with a drill bit (15) connected to the mandrel. Longitudinally extending helical groove means (20) are provided in the mandrel and roller means (21) are supported on the drill string and engaged with the helical groove means. Spring means (23) is supported by the drill string and abuts the mandrel to tend to urge the mandrel longitudinally out of the drill string whereby the bit is urged into substantially continuous contact with the well bore bottom (16) as the drill string is rotated during drilling operations. Valve means (30) are provided for selectively circulating fluids from the drill string to the well bore above the drill bit, and when desired jar means (8) may be incorporated in the drill string to impart an up or down jar thereto should the drill string become stuck or tend to become stuck during drilling operations.

IPC 1-7

E21B 17/07; E21B 21/10; E21B 34/12

IPC 8 full level

E21B 17/07 (2006.01); E21B 21/10 (2006.01); E21B 34/12 (2006.01)

CPC (source: EP)

E21B 17/073 (2013.01); E21B 21/103 (2013.01); E21B 34/12 (2013.01)

Citation (search report)

Designated contracting state (EPC)

DE FR GB

DOCDB simple family (publication)

EP 0065601 A1 19821201

DOCDB simple family (application)

EP 81302299 A 19810522