(19)

(11)

EP 1 963 621 A1

(12)

(43) Date of publication: 03.09.2008 Bulletin 2008/36 (21) Application number: 06787454.5 (22) Date of filing: 14.07.2006

(51) International Patent Classification (IPC):  E21B 44/00(2006.01) E21B 43/00(2006.01) (86) International application number: PCT/US2006/027548 (87) International publication number: WO 2007/011812 (25.01.2007 Gazette 2007/04)

(84) Designated Contracting States: AT BE BG CH CY CZ DE DK EE ES FI FR GB GR HU IE IS IT LI LT LU LV MC NL PL PT RO SE SI SK TR (30) Priority: 16.07.2005 US 699759 P (71) Applicant: P.E.T. International, Inc. Houston, TX 77058 (US)	(72) Inventor: CRAWFORD, James, B. Lafayette, LA 70503 (US) (74) Representative: Paul, Richard  Murgitroyd & Company, 165-169 Scotland Street Glasgow G5 8QA Glasgow G5 8QA (GB)