(19)

(11)

EP 0 821 767 A1

(12)

(43) Date of publication: 04.02.1998 Bulletin 1998/06 (21) Application number: 96905605.0 (22) Date of filing: 20.03.1996

(51) International Patent Classification (IPC):  E21B 4/ 14( . ) (86) International application number: PCT/AU1996/000153 (87) International publication number: WO 1996/029520 (26.09.1996 Gazette 1996/43)

(84) Designated Contracting States: ES FR GB IE SE (30) Priority: 21.03.1995 AU 1979PN00184 29.03.1995 AU 1999PN00201 (71) Applicant: Rear, Ian Graeme Bassendean, W.A. 6053 (AU)	(72) Inventor: Rear, Ian Graeme Bassendean, W.A. 6053 (AU) (74) Representative: Baillie, Iain Cameron, et al  c/o Ladas & Parry 52-54 High Holborn London WC1V 6RR London WC1V 6RR (GB)