(19)
(11) EP 0 865 613 A1

(12)

(43) Date of publication:
23.09.1998 Bulletin 1998/39

(21) Application number: 96937962.0

(22) Date of filing: 22.11.1996
(51) International Patent Classification (IPC): 
E21B 17/ 00( . )
E21B 47/ 01( . )
E21B 47/ 12( . )
G01V 3/ 18( . )
 E21B 17/ 10( . )
E21B 47/ 08( . )
G01V 1/ 40( . )
G01V 5/ 04( . )
(86) International application number:
PCT/CA1996/000768
(87) International publication number:
WO 1997/021117 (12.06.1997 Gazette 1997/25)
(84) Designated Contracting States:
DE DK ES FR GB GR IE IT NL PT

(30) Priority: 05.12.1995 US 19950567337
31.10.1996 US 19960740665

(71) Applicant: LWT INSTRUMENTS INC.
Calgary Alberta T2P 0J9 (CA)

(72) Inventors:
  • POMERLEAU, Daniel, Guy
    Calgary, Alberta T3A 3Z6 (CA)
  • SPENCER, Brian
    Lincoln, NE 68516 (US)
  • VOGHELL, Mark
    Edmonton, Alberta T6K 2L9 (CA)
  • MacLEAN, Doug
    Ardrossan, Alberta T8G 2A1 (CA)
  • PASTUSHAK, Paul
    Edmonton, Alberta T6R 1C6 (CA)

(74) Representative: Carter, Caroline Ann, et al 
ABEL & IMRAY Northumberland House 303-306 High Holborn
London WC1V 7LH
London WC1V 7LH (GB)

   


(54) COMPOSITE MATERIAL STRUCTURES HAVING REDUCED SIGNAL ATTENUATION