(19)

(11)

EP 2 614 217 A1

(12)

(43) Date of publication: 17.07.2013 Bulletin 2013/29 (21) Application number: 11822919.4 (22) Date of filing: 28.02.2011

(51) International Patent Classification (IPC):  E21B 44/06(2006.01) B23B 45/04(2006.01) E21B 1/38(2006.01) E21B 44/00(2006.01) (86) International application number: PCT/AU2011/000220 (87) International publication number: WO 2012/031311 (15.03.2012 Gazette 2012/11)

(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 (30) Priority: 10.09.2010 AU 2010904066 (71) Applicant: Rockdrill Services Australia Pty Ltd West Heidelberg, Victoria 3081 (AU)	(72) Inventors: SANGSTER, Alexander West Heidelberg, Victoria 3081 (AU) KANG, Dechun West Heidelberg, Victoria 3081 (AU) WHYTE, Geoffrey West Heidelberg, Victoria 3081 (AU) (74) Representative: Harrison Goddard Foote LLP  Delta House 50 West Nile Street Glasgow G1 2NP 50 West Nile Street Glasgow G1 2NP (GB)