(19)

(11)

EP 3 310 988 A1

(12)

(43) Date of publication: 25.04.2018 Bulletin 2018/17 (21) Application number: 15729832.4 (22) Date of filing: 17.06.2015

(51) International Patent Classification (IPC):  E21B 7/02(2006.01) E21B 21/00(2006.01) E21B 44/00(2006.01) (86) International application number: PCT/EP2015/063509 (87) International publication number: WO 2016/202369 (22.12.2016 Gazette 2016/51)

(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 Designated Validation States: MA (71) Applicant: Sandvik Mining and Construction Oy 33330 Tampere (FI)	(72) Inventor: HANSKI, Sami 33330 Tampere (FI) (74) Representative: Sandvik  Sandvik Intellectual Property AB 811 81 Sandviken 811 81 Sandviken (SE)