(19)

(11)

EP 2 809 868 A2

(12)

(88) Date of publication A3: 30.05.2014 (43) Date of publication: 10.12.2014 Bulletin 2014/50 (21) Application number: 13714691.6 (22) Date of filing: 25.01.2013

(51) International Patent Classification (IPC):  E21B 10/12(2006.01) (86) International application number: PCT/IB2013/050664 (87) International publication number: WO 2013/114258 (08.08.2013 Gazette 2013/32)

(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: 30.01.2012 NO 20120100 (71) Applicant: Stein Narvestad A.S 0259 Oslo (NO)	(72) Inventor: NARVESTAD, Stein 0259 Oslo (NO) (74) Representative: Onsagers AS  P.O. Box 1813 Vika 0123 Oslo 0123 Oslo (NO)