(19)

(11)

EP 0 310 633 A1

(12)

(43) Date of publication: 12.04.1989 Bulletin 1989/15 (21) Application number: 88901349.0 (22) Date of filing: 03.02.1988

(51) International Patent Classification (IPC):  G01V 3/ 24( . ) (86) International application number: PCT/US1988/000034 (87) International publication number: WO 1988/007212 (22.09.1988 Gazette 1988/21)

(84) Designated Contracting States: DE FR GB NL (30) Priority: 16.03.1987 US 19870025937 (71) Applicant: EXPLORATION LOGGING, INC. Sacramento, CA 95821 (US)	(72) Inventors: MEISNER, James, Edward Citrus Heights, CA 95610 (US) SQUIRE, Roy, Earl Sacramento, CA 95823 (US) HALL, Ronald, Anthony Sacramento, CA 95826 (US) BROOKS, Andrew, Goodwin Rancho Cordova, CA 95670 (US) (74) Representative: Slight, Geoffrey Charles, et al  Graham Watt & Co. Riverhead Sevenoaks Kent TN13 2BN Sevenoaks Kent TN13 2BN (GB)