(19)

(11)

EP 2 304 160 A1

(12)

(43) Date of publication: 06.04.2011 Bulletin 2011/14 (21) Application number: 09794789.9 (22) Date of filing: 30.06.2009

(51) International Patent Classification (IPC):  E21B 7/24(2006.01) (86) International application number: PCT/US2009/003890 (87) International publication number: WO 2010/005522 (14.01.2010 Gazette 2010/02)

(84) Designated Contracting States: AT BE BG CH CY CZ DE DK EE ES FI FR GB GR HR HU IE IS IT LI LT LU LV MC MK MT NL NO PL PT RO SE SI SK TR Designated Extension States: AL BA RS (30) Priority: 30.06.2008 US 133558 P (71) Applicant: Bochenek, Water Chicago, IL 60634 (US)	(72) Inventor: Bochenek, Water Chicago, IL 60634 (US) (74) Representative: Sewell, Adrian David et al Murgitroyd & Company 165-169 Scotland Street Glasgow, Strathclyde G5 8PL Glasgow, Strathclyde G5 8PL (GB)