(19)

(11)

EP 0 980 461 A2

(12)

(88) Date of publication A3: 04.11.1999 (43) Date of publication: 23.02.2000 Bulletin 2000/08 (21) Application number: 98923228.5 (22) Date of filing: 08.05.1998

(51) International Patent Classification (IPC)7: E21B 15/04, E21B 7/02, E21B 7/04 (86) International application number: PCT/NZ9800/055 (87) International publication number: WO 9850/667 (12.11.1998 Gazette 1998/45)

(84) Designated Contracting States: AT BE CH CY DE DK ES FI FR GB GR IE IT LI LU MC NL PT SE (30) Priority: 08.05.1997 NZ 31476997 28.05.1997 NZ 31493897 27.03.1998 NZ 33008098 (71) Applicants: Flexidrill Limited Takapuna, Auckland (NZ) West, Gregory Donald Takapuna, Auckland (NZ)	(72) Inventor: WEST, Gregory Donald Takapuna,Auckland (NZ) (74) Representative: Beresford, Keith Denis Lewis et al 2-5 Warwick CourtHigh Holborn London WC1R 5DJ London WC1R 5DJ (GB)