(19)
(11) EP 0 408 667 A1

(12)

(43) Date of publication:
23.01.1991 Bulletin 1991/04

(21) Application number: 89905949.0

(22) Date of filing: 21.04.1989
(51) International Patent Classification (IPC): 
G01V 1/ 40( . )
E21B 47/ 16( . )
(86) International application number:
PCT/US1989/001641
(87) International publication number:
WO 1989/010572 (02.11.1989 Gazette 1989/26)
(84) Designated Contracting States:
DE FR GB NL

(30) Priority: 21.04.1988 US 19880184326

(60) Divisional application:
93111079.5 / 0565141

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

(72) Inventor:
  • DRUMHELLER, Douglas, Schaeffer
    Cedar Crest, NM 87008 (US)

(74) Representative: Meyers, Ernest 
Office de Brevets FREYLINGER & ASSOCIES B.P. 1 321, route d'Arlon
L-8001 Strassen
L-8001 Strassen (LU)

   


(54) ACOUSTIC DATA TRANSMISSION THROUGH A DRILL STRING