(19)

(11)

EP 2 347 089 A1

(12)

(43) Date of publication: 27.07.2011 Bulletin 2011/30 (21) Application number: 09748460.4 (22) Date of filing: 03.11.2009

(51) International Patent Classification (IPC):  E21B 33/035(2006.01) E21B 41/00(2006.01) E21B 34/10(2006.01) (86) International application number: PCT/GB2009/051477 (87) International publication number: WO 2010/052490 (14.05.2010 Gazette 2010/19)

(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 SM TR Designated Extension States: AL BA RS (30) Priority: 07.11.2008 GB 0820326 (71) Applicant: Vectro Gray Control Limited Bristol BS48 1BS (GB)	(72) Inventor: DAVEY, Peter John Somerset BS22 9YR (GB) (74) Representative: Emerson, Peter James et al Page Hargrave Whitefriars Lewins Mead GB-Bristol BS1 2NT GB-Bristol BS1 2NT (GB)