(19)

(11)

EP 3 688 276 A1

(12)

(43) Date of publication: 05.08.2020 Bulletin 2020/32 (21) Application number: 17927240.6 (22) Date of filing: 26.09.2017

(51) International Patent Classification (IPC):  E21B 43/25(2006.01) E21B 33/124(2006.01) E21B 43/263(2006.01) E21B 17/02(2006.01) E21B 43/26(2006.01) (86) International application number: PCT/CA2017/051135 (87) International publication number: WO 2019/060977 (04.04.2019 Gazette 2019/14)

(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 (71) Applicant: Rocketfrac Services Ltd. Calgary, AB T2C 2H9 (CA)	(72) Inventors: FREEMAN, Spencer Eric Calgary, Alberta T2W 4J9 (CA) HARCOURT, Michael Geoffrey Calgary, Alberta T2V 1G1 (CA) (74) Representative: Letzelter, Felix Phillip  Meissner Bolte Patentanwälte Rechtsanwälte Partnerschaft mbB Widenmayerstraße 47 80538 München 80538 München (DE)