(19)

(11)

EP 1 402 494 A2

(12)

(88) Date of publication A3: 24.12.2003 (43) Date of publication: 31.03.2004 Bulletin 2004/14 (21) Application number: 01928409.0 (22) Date of filing: 09.04.2001

(51) International Patent Classification (IPC)7: G08B 23/00 (86) International application number: PCT/US2001/011496 (87) International publication number: WO 2002/001605 (03.01.2002 Gazette 2002/01)

(84) Designated Contracting States: AT BE CH CY DE DK ES FI FR GB GR IE IT LI LU MC NL PT SE TR Designated Extension States: AL LT LV MK RO SI (30) Priority: 28.06.2000 US 605903 (71) Applicant: Schlumbergersema Inc. Alpharetta, GA 30022 (US)	(72) Inventor: MORAND, Gary, W. Duluth, GA 30096 (US) (74) Representative: Bergmeier, Werner, Dipl.-Ing.  Friedrich-Ebert-Strasse 84 85055 Ingolstadt 85055 Ingolstadt (DE)