(19)

(11)

EP 3 310 991 A1

(12)

(43) Date of publication: 25.04.2018 Bulletin 2018/17 (21) Application number: 16728984.2 (22) Date of filing: 15.06.2016

(51) International Patent Classification (IPC):  E21B 29/10(2006.01) E21B 43/10(2006.01) E21B 33/124(2006.01) E21B 43/14(2006.01) (86) International application number: PCT/EP2016/063704 (87) International publication number: WO 2016/202834 (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 MD (30) Priority: 16.06.2015 EP 15172292 12.02.2016 EP 16155527 (71) Applicant: Welltec A/S 3450 Allerød (DK)	(72) Inventor: HAZEL, Paul Aberdeen Aberdeenshire AB41/7JQ (GB) (74) Representative: Hoffmann Dragsted A/S  Rådhuspladsen 16 1550 Copenhagen V 1550 Copenhagen V (DK)