(19)

(11)

EP 1 392 952 A1

(12)

(43) Date of publication: 03.03.2004 Bulletin 2004/10 (21) Application number: 02732890.5 (22) Date of filing: 29.05.2002

(51) International Patent Classification (IPC)7: E21B 10/64, E21B 7/00, E21B 17/02 (86) International application number: PCT/GB2002/002262 (87) International publication number: WO 2002/099243 (12.12.2002 Gazette 2002/50)

(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: 04.06.2001 GB 0113498 (71) Applicant: High Mead Developments Limited Berkhampsted,Hertfordshire HP4 2BQ (GB)	(72) Inventors: HOLLINGSWORTH, John, Richard Berkhamsted,Herts HP4 3LZ (GB) UNSWORTH, James, Michael Aylesbury,Bucks HP20 1PH (GB) (74) Representative: Stainthorpe, Vanessa Juliet  Harrison Goddard FooteFountain PrecinctLeopold Street Sheffield S1 2QD Sheffield S1 2QD (GB)