(19)

(11)

EP 1 283 938 A1

(12)

(43) Date of publication: 19.02.2003 Bulletin 2003/08 (21) Application number: 01938367.8 (22) Date of filing: 25.05.2001

(51) International Patent Classification (IPC)7: E21B 23/01, E21B 23/04 (86) International application number: PCT/GB0102/368 (87) International publication number: WO 0109/0530 (29.11.2001 Gazette 2001/48)

(84) Designated Contracting States: AT BE CH CY DE DK ES FI FR GB GR IE IT LI LU MC NL PT SE TR (30) Priority: 26.05.2000 GB 0012769 (71) Applicant: Weatherford/Lamb Inc. Wilmington, DE 19805 (US)	(72) Inventors: LAWRENCE, Lewis KemnayAberdeenshire AB51 5LH (GB) SCOTT, Brian AlfordAberdeenshire AB33 8HN (GB) MARTIN, David InverurieAberdeenshire AB51 5DE (GB) MAKIN, Graeme DunechtAberdeenshire AB35 7BE (GB) FERGUSON, Stuart Aberdeen AB15 4UQ (GB) (74) Representative: Harding, Richard Patrick  Marks & Clerk,4220 Nash CourtOxford Business Park South Oxford OX4 2RU Oxford OX4 2RU (GB)