(19)

(11)

EP 1 234 100 A2

(12)

(88) Date of publication A3: 13.12.2001 (43) Date of publication: 28.08.2002 Bulletin 2002/35 (21) Application number: 00989922.0 (22) Date of filing: 28.11.2000

(51) International Patent Classification (IPC)7: E21B 43/30 (86) International application number: PCT/EP0011/993 (87) International publication number: WO 0104/0624 (07.06.2001 Gazette 2001/23)

(84) Designated Contracting States: AT BE CH CY DE DK ES FI FR GB GR IE IT LI LU MC NL PT Designated Extension States: AL LT LV MK RO SI (30) Priority: 29.11.1999 EP 99204025 (71) Applicant: SHELL INTERNATIONALE RESEARCHMAATSCHAPPIJ B.V. 2596 HR Den Haag (NL)	(72) Inventor: HEIJNEN, Wilhelmus, Hubertus, Paulus, Maria NL-1951 GN Velsen (NL)