(19)

(11)

EP 2 678 522 A2

(12)

(88) Date of publication A3: 27.06.2013 (43) Date of publication: 01.01.2014 Bulletin 2014/01 (21) Application number: 12704995.5 (22) Date of filing: 03.02.2012

(51) International Patent Classification (IPC):  E21B 37/06(2006.01) E21B 41/02(2006.01) (86) International application number: PCT/US2012/023773 (87) International publication number: WO 2012/115763 (30.08.2012 Gazette 2012/35)

(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 (30) Priority: 24.02.2011 US 201113034546 (71) Applicant: Baker Hughes Incorporated Houston, TX 77019 (US)	(72) Inventor: DARBY, John Gregory Montgomery, Texas 77356 (US) (74) Representative: Hoffmann, Benjamin  Dehns St. Bride's House 10 Salisbury Square London EC4Y 8JD London EC4Y 8JD (GB)