(19)

(11)

EP 2 271 822 A2

(12)

(88) Date of publication A3: 19.08.2010 (43) Date of publication: 12.01.2011 Bulletin 2011/02 (21) Application number: 09726962.5 (22) Date of filing: 01.04.2009

(51) International Patent Classification (IPC):  E21B 43/12(2006.01) E21B 33/124(2006.01) E21B 34/08(2006.01) (86) International application number: PCT/NO2009/000124 (87) International publication number: WO 2009/123472 (08.10.2009 Gazette 2009/41)

(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: 03.04.2008 NO 20081657 (71) Applicant: Statoil ASA 4035 Stavanger (NO)	(72) Inventors: MATHIESEN, Vidar N-3944 Porsgrunn (NO) AAKRE, Haavard N-3744 Skien (NO) (74) Representative: Schmidt, Claus Christian  Zacco Norway AS Haakon VII's gate 2 Post box 2003 Vika 0125 Oslo 0125 Oslo (NO)