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(11)

EP 3 286 405 A1

(12)

(43) Date of publication: 28.02.2018 Bulletin 2018/09 (21) Application number: 16783858.0 (22) Date of filing: 21.04.2016

(51) International Patent Classification (IPC):  E21B 19/09(2006.01) E21B 7/128(2006.01) E21B 19/00(2006.01) E21B 7/12(2006.01) E21B 17/01(2006.01) E21B 19/084(2006.01) (86) International application number: PCT/US2016/028654 (87) International publication number: WO 2016/172345 (27.10.2016 Gazette 2016/43)

(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: 21.04.2015 US 201562150725 P (71) Applicant: Transocean Sedco Forex Ventures Limited George Town, Grand Cayman KY1-1003 (KY)	(72) Inventors: BOURGEAU, Edward, Peter Kenneth Houston, TX 77079 (US) WU, Yin Houston, TX 77098 (US) (74) Representative: Hoffmann Eitle  Patent- und Rechtsanwälte PartmbB Arabellastraße 30 81925 München 81925 München (DE)