(19)

(11)

EP 1 499 789 A2

(12)

(88) Date of publication A3: 15.07.2004 (43) Date of publication: 26.01.2005 Bulletin 2005/04 (21) Application number: 03746666.1 (22) Date of filing: 09.04.2003

(51) International Patent Classification (IPC)7: E21B 7/18 (86) International application number: PCT/US2003/010813 (87) International publication number: WO 2003/087522 (23.10.2003 Gazette 2003/43)

(84) Designated Contracting States: AT BE BG CH CY CZ DE DK EE ES FI FR GB GR HU IE IT LI LU MC NL PT RO SE SI SK TR Designated Extension States: AL LT LV MK (30) Priority: 10.04.2002 US 119790 (71) Applicant: Buckman Jet Drilling, Inc. Bowling Green, KY 42101 (US)	(72) Inventors: BUCKMAN, William, G., Sr. Bowling Green, KY 42101 (US) DOTSON, Thomas, L. Bowling Green, KY 42104 (US) MCDANIELS, Michael, D. Glasgow, KY 42141 (US) BELL, Wendell, S. Glasgow, KY 42141 (US) (74) Representative: Grubert, Andreas  Baker Botts99 Gresham Street London EC2V 7BA London EC2V 7BA (GB)