(19)

(11)

EP 2 379 895 A2

(12)

(88) Date of publication A3: 16.09.2010 (43) Date of publication: 26.10.2011 Bulletin 2011/43 (21) Application number: 09839028.9 (22) Date of filing: 17.12.2009

(51) International Patent Classification (IPC):  F15D 1/10(2006.01) E21B 17/01(2006.01) F15D 1/06(2006.01) (86) International application number: PCT/US2009/068513 (87) International publication number: WO 2010/085302 (29.07.2010 Gazette 2010/30)

(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 SM TR (30) Priority: 22.01.2009 US 146526 P (71) Applicants: Shell Oil Company Houston, TX 77252-2463 (US) SM  Shell Internationale Research Maatschappij B.V. 2596 HR Den Haag (NL)

(72) Inventors: ALLEN, Donald Wayne Richmond Texas 77469 (US) EFTHYMIOU, Michalakis NL-2288 GD Rijswijk (NL) HENNING, Dean Leroy Needville Texas 77461 (US) KUIPER, Guido Leon NL-2611 AV Delft (NL) LEE, Li Houston Texas 77024 (US) (74) Representative: Matthezing, Robert Maarten et al Shell Internationale Reseach Maatschappij B.V. Intellectual Property Services P.O. Box 384 2501 CJ The Hague 2501 CJ The Hague (NL)