(19)

(11)

EP 1 266 117 A1

(12)

(43) Date of publication: 18.12.2002 Bulletin 2002/51 (21) Application number: 00955167.2 (22) Date of filing: 20.03.2000

(51) International Patent Classification (IPC)7: E21B 17/01, E21B 19/24 (86) International application number: PCT/NO0000/097 (87) International publication number: WO 0107/1153 (27.09.2001 Gazette 2001/39)

(84) Designated Contracting States: AT BE CH CY DE DK ES FI FR GB GR IE IT LI LU MC NL PT SE Designated Extension States: AL LT LV MK RO SI (71) Applicant: National Oilwell Norway AS 4069 Stavanger (NO)	(72) Inventor: GJEDEBO, Jon, Grude N-4012 Stavanger (NO) (74) Representative: Lucas, Brian Ronald  Lucas & Co.135 Westhall Road WarlinghamSurrey CR6 9HJ WarlinghamSurrey CR6 9HJ (GB)