(19)

(11)

EP 2 809 877 A2

(12)

(88) Date of publication A3: 13.03.2014 (43) Date of publication: 10.12.2014 Bulletin 2014/50 (21) Application number: 12791345.7 (22) Date of filing: 29.10.2012

(51) International Patent Classification (IPC):  E21B 41/00(2006.01) E21B 33/12(2006.01) (86) International application number: PCT/US2012/062465 (87) International publication number: WO 2013/066825 (10.05.2013 Gazette 2013/19)

(84) Designated Contracting States: AL 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 RS SE SI SK SM TR Designated Extension States: BA ME (30) Priority: 31.10.2011 US 201161553474 P (71) Applicants: Aronstam, Peter S. Houston, Texas 77041 (US) Fincher, Roger W. Conroe, Texas 77304 (US)	(72) Inventors: Aronstam, Peter S. Houston, Texas 77041 (US) Fincher, Roger W. Conroe, Texas 77304 (US) (74) Representative: Acapo AS  P.O. Box 1880 Nordnes 5817 Bergen 5817 Bergen (NO)