Acoustic data transmission through a drill string

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(11)

EP 0 565 141 A3

(12)	EUROPEAN PATENT APPLICATION

(88)	Date of publication A3:
	20.10.1993 Bulletin 1993/42

(43)	Date of publication A2:
	13.10.1993 Bulletin 1993/41

(21)	Application number: 93111079.5

(22)	Date of filing: 21.04.1989

(51)	International Patent Classification (IPC)⁵: E21B 47/12

(84)	Designated Contracting States:
	DE FR GB NL

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Priority:

21.04.1988 US 184326

(62)	Application number of the earlier application in accordance with Art. 76 EPC:
	89905949.7 / 0408667

(71)	Applicant: SANDIA CORPORATION
	Albuquerque, NM 87185-5800 (US)

(72)	Inventor:
	Drumheller, Douglas Schaeffer Cedar Crest, New Mexico 87008 (US)

(74)	Representative: Freylinger, Ernest T.
	Office de Brevets Ernest T. Freylinger 321, route d'Arlon Boîte Postale 48 L-8001 Strassen L-8001 Strassen (LU)

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References cited: :

(54)	Acoustic data transmission through a drill string

(57) Acoustical signals are transmitted through a drill string by canceling upward moving acoustical noise and by preconditioning the data in recognition of the comb filter impedance characteristics of the drill string.

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