EP 0087418 A4 19850626 - APPARATUS FOR WELL LOGGING WHILE DRILLING.
Title (en)
APPARATUS FOR WELL LOGGING WHILE DRILLING.
Title (de)
EINRICHTUNG FÜR BOHRLOCHMESSUNGEN WÄHREND DES BOHRENS.
Title (fr)
APPAREIL DE RADIOCAROTTAGE PENDANT LE FORAGE.
Publication
Application
Priority
US 30244681 A 19810915
Abstract (en)
[origin: WO8301087A1] A monostable, solenoid-operated valve in a passage which bypasses the drilling fluid pressure drop across a drill bit (34) at the lower end of a drill string (28) in a well opens and closes in response to downhole conditions to create pressure pulses in the drilling fluid. The valve (166) is urged toward a closed position by drilling fluid pumped through the drill string. A larger force is required to open the valve (166) than to hold it open. Current supplied to the solenoid (67, 70) to open the valve is thereafter reduced to a value sufficient to hold the valve open. The solenoid is de-energized to close the valve.
IPC 1-7
IPC 8 full level
E21B 21/10 (2006.01); E21B 47/00 (2006.01); E21B 47/18 (2006.01)
CPC (source: EP)
E21B 21/103 (2013.01); E21B 47/18 (2013.01); E21B 47/22 (2020.05)
Citation (search report)
- [XD] WO 8002051 A1 19801002 - EXPLORATION LOGGING INC [US]
- [X] GB 2009473 A 19790613 - GEARHART OWEN INDUSTRIES
- [A] US 2964116 A 19601213 - PETERSON ELWIN W
Designated contracting state (EPC)
DE FR NL
DOCDB simple family (publication)
WO 8301087 A1 19830331; AU 548627 B2 19851219; AU 7724581 A 19830408; DK 214783 A 19830513; DK 214783 D0 19830513; EP 0087418 A1 19830907; EP 0087418 A4 19850626; GB 2114632 A 19830824; GB 2114632 B 19850515; GB 8309495 D0 19830511; NO 831701 L 19830513
DOCDB simple family (application)
US 8101328 W 19811002; AU 7724581 A 19811002; DK 214783 A 19830513; EP 81902875 A 19811002; GB 8309495 A 19811002; NO 831701 A 19830513