(19)

(11)

EP 2 486 220 A1

(12)

(43) Date of publication: 15.08.2012 Bulletin 2012/33 (21) Application number: 10766318.9 (22) Date of filing: 15.09.2010

(51) International Patent Classification (IPC):  E21B 10/56(2006.01) E21B 10/567(2006.01) E21B 10/633(2006.01) E21B 29/00(2006.01) E21B 10/627(2006.01) (86) International application number: PCT/GB2010/051545 (87) International publication number: WO 2011/042715 (14.04.2011 Gazette 2011/15)

(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 SE SI SK SM TR (30) Priority: 09.10.2009 GB 0917704 (71) Applicant: Cutting & Wear Resistant Developments Limited South Yorkshire S60 1RW (GB)	(72) Inventors: RUSSELL, Mark Sheffield South Yorkshire S6 6LB (GB) OLLERENSHAW, Andy Sheffield South Yorkshire S6 6RB (GB) (74) Representative: Stainthorpe, Vanessa Juliet  Harrison Goddard Foote Fountain Precinct Balm Green Sheffield S1 2JA Sheffield S1 2JA (GB)