(19)

(11)

EP 1 623 088 A1

(12)

(43) Date of publication: 08.02.2006 Bulletin 2006/06 (21) Application number: 04759432.0 (22) Date of filing: 12.04.2004

(51) International Patent Classification (IPC):  E21B 21/06(1980.01) (86) International application number: PCT/US2004/011192 (87) International publication number: WO 2004/092534 (28.10.2004 Gazette 2004/44)

(84) Designated Contracting States: AT BE BG CH CY CZ DE DK EE ES FI FR GB GR HU IE IT LI LU MC NL PL PT RO SE SI SK TR (30) Priority: 15.04.2003 US 463021 P (71) Applicant: CABOT CORPORATION Boston, Massachusetts 02210-2019 (US)	(72) Inventor: HARRIS, Michael J. Cove Bay, Aberdeen AB12 3HD (GB) (74) Representative: Grünecker, Kinkeldey, Stockmair & Schwanhäusser Anwaltssozietät  Maximilianstrasse 58 80538 München 80538 München (DE)