(19)

(11)

EP 1 354 126 A1

(12)

(43) Date of publication: 22.10.2003 Bulletin 2003/43 (21) Application number: 02710991.7 (22) Date of filing: 23.01.2002

(51) International Patent Classification (IPC)7: E21B 47/18 (86) International application number: PCT/GB0200/302 (87) International publication number: WO 0205/9461 (01.08.2002 Gazette 2002/31)

(84) Designated Contracting States: AT BE CH CY DE DK ES FI FR GB GR IE IT LI LU MC NL PT SE TR Designated Extension States: AL LT LV MK RO SI (30) Priority: 24.01.2001 GB 0101806 (71) Applicant: Geolink(UK) Limited Dyce, Aberdeen AB21 0GZ (GB)	(72) Inventors: PRAIN, Kenneth,Geolink (UK) Ltd Aberdeen AB21 0GZ (GB) KNIGHT, John Banchory,Kincardineshire AB31 5JD (GB) (74) Representative: Orr, William McLean  Urquhart-Dykes & Lord,Tower House,Merrion Way Leeds LS2 8PA Leeds LS2 8PA (GB)