(19)

(11)

EP 2 929 123 A2

(12)

(88) Date of publication A3: 24.12.2014 (43) Date of publication: 14.10.2015 Bulletin 2015/42 (21) Application number: 13810985.5 (22) Date of filing: 03.12.2013

(51) International Patent Classification (IPC):  E21B 23/04(2006.01) E21B 34/14(2006.01) (86) International application number: PCT/GB2013/053199 (87) International publication number: WO 2014/087153 (12.06.2014 Gazette 2014/24)

(84) Designated Contracting States: AL 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 RS SE SI SK SM TR Designated Extension States: BA ME (30) Priority: 04.12.2012 GB 201221837 (71) Applicant: Petrowell Limited Aberdeen AB12 3LF (GB)	(72) Inventors: PATTON, Damien Gerard Huntly Aberdeenshire AB54 4NL (GB) WEBSTER, Oliver Torphins Aberdeenshire AB31 4HH (GB) PURKIS, Daniel George Aberdeen Aberdeenshire AB42 0QH (GB) (74) Representative: Moreland, David  Marks & Clerk LLP Aurora 120 Bothwell Street Glasgow G2 7JS Glasgow G2 7JS (GB)