(19)

(11)

EP 1 395 729 A1

(12)

(43) Date of publication: 10.03.2004 Bulletin 2004/11 (21) Application number: 02703751.4 (22) Date of filing: 13.03.2002

(51) International Patent Classification (IPC)7: E21B 7/04, E21B 7/20 (86) International application number: PCT/GB2002/001026 (87) International publication number: WO 2003/031762 (17.04.2003 Gazette 2003/16)

(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: 19.03.2001 US 812070 07.03.2002 GB 0205389 (71) Applicant: Lattice Intellectual Property Limited London WC2N 5EH (GB)	(72) Inventor: DIMITROFF, Theodore, Roy Columbia, MO 65201 (US) (74) Representative: Kunz, Herbert, Dr.  HammondsRechtsanwälte/PatentanwälteThomas-Wimmer-Ring 17 80539 München 80539 München (DE)