(19)

(11)

EP 2 255 059 A1

(12)

(43) Date of publication: 01.12.2010 Bulletin 2010/48 (21) Application number: 09708493.3 (22) Date of filing: 09.02.2009

(51) International Patent Classification (IPC):  E21B 3/02(2006.01) E21B 21/10(2006.01) E21B 19/16(2006.01) (86) International application number: PCT/GB2009/000339 (87) International publication number: WO 2009/098474 (13.08.2009 Gazette 2009/33)

(84) Designated Contracting States: AT BE BG CH CY CZ DE DK EE ES FI FR GB GR HR HU IE IS IT LI LT LU LV MC MK MT NL NO PL PT RO SE SI SK TR Designated Extension States: AL BA RS (30) Priority: 08.02.2008 GB 0802406 08.02.2008 GB 0802407 20.03.2008 GB 0805299 (71) Applicant: Pilot Drilling Control Limited Suffolk NR32 3LZ (GB)	(72) Inventors: SWIETLIK, George Suffolk NR32 3PL (GB) LARGE, Robert Lowestoft NR33 8NG (GB) (74) Representative: Dowling, Andrew  Haseltine Lake LLP Lincoln House, 5th Floor 300 High Holborn GB-London WC1V 7JH GB-London WC1V 7JH (GB)