(19)

(11)

EP 1 549 820 A1

(12)

(43) Date of publication: 06.07.2005 Bulletin 2005/27 (21) Application number: 03758307.7 (22) Date of filing: 10.10.2003

(51) International Patent Classification (IPC)7: E21B 17/00, E21B 17/02, E21B 47/12 (86) International application number: PCT/GB2003/004417 (87) International publication number: WO 2004/033847 (22.04.2004 Gazette 2004/17)

(84) Designated Contracting States: AT BE BG CH CY CZ DE DK EE ES FI FR GB GR HU IE IT LI LU MC NL PT RO SE SI SK TR Designated Extension States: AL LT LV MK (30) Priority: 10.10.2002 US 417525 P 21.10.2002 US 420052 P 22.10.2002 US 420381 P 28.01.2003 US 442992 P (71) Applicant: Varco I/P, Inc. Houston, TX 77042 (US)	(72) Inventors: BOYADJIEFF, George Villa Park, CA 92861 (US) WILLIAMS, Barry Rosharon, TX 77583 (US) PONTIUS, Bruce Scottsdale, AZ 85254 (US) (74) Representative: Lucas, Brian Ronald  Lucas & Co.135 Westhall Road Warlingham,Surrey CR6 9HJ Warlingham,Surrey CR6 9HJ (GB)