A STEERABLE DRILLING ASSEMBLY FOR MOUNTING ON THE END OF A DRILL STRING TO DRILL A BOREHOLE IN AN UNDERGROUND FORMATION - Patent 0612370

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EP 0 612 370 A1

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(43)	Date of publication:
	31.08.1994 Bulletin 1994/35

(21)	Application number: 92924581.0

(22)	Date of filing: 18.11.1992

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International Patent Classification (IPC):

E21B 4/ 02^{( . )}
E21B 7/ 06^{( . )}
E21B 17/ 10^{( . )}

E21B 4/ 18^{( . )}
E21B 7/ 08^{( . )}
E21B 23/ 00^{( . )}

(86)	International application number:
	PCT/DK1992/000341

(87)	International publication number:
	WO 1993/010326 (27.05.1993 Gazette 1993/13)

(84)	Designated Contracting States:
	AT BE CH DE DK ES FR GB GR IE IT LI LU MC NL SE

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Priority:

19.11.1991 DK 19910001884

(71)	Applicant: HTC A/S
	DK-2600 Glostrup (DK)

(72)	Inventor:
	HALLUNDBAEK, Jorgen DK-2800 Lyngby (DK)

(74)	Representative: WITTRUP, Flemming, et al
	c/o Hofman-Bang & Boutard A/S Adelgade 15 DK-1304 Copenhagen K DK-1304 Copenhagen K (DK)

(54)	A STEERABLE DRILLING ASSEMBLY FOR MOUNTING ON THE END OF A DRILL STRING TO DRILL A BOREHOLE IN AN UNDERGROUND FORMATION