(19)

(11)

EP 1 941 123 A1

(12)

(43) Date of publication: 09.07.2008 Bulletin 2008/28 (21) Application number: 06826749.1 (22) Date of filing: 25.10.2006

(51) International Patent Classification (IPC):  E21B 4/18(2006.01) E21B 7/20(2006.01) E21B 23/14(2006.01) E21B 43/10(2006.01) (86) International application number: PCT/US2006/041806 (87) International publication number: WO 2007/050770 (03.05.2007 Gazette 2007/18)

(84) Designated Contracting States: DE FR GB IT NL (30) Priority: 27.10.2005 US 731988 P (71) Applicant: Shell Internationale Research Maatschappij B.V. 2596 HR Den Haag (NL)	(72) Inventors: FILIPPOV, Andrei, Gregory Houston, Texas 77056 (US) HOU, Fu, Joseph Missouri City, Texas 77459 (US) (74) Representative: Zeestraten, Albertus W. J. et al Shell International B.V., Intellectual Property Services, P.O. Box 384 2501 CJ The Hague 2501 CJ The Hague (NL)