(19)

(11)

EP 3 642 297 A1

(12)

(43) Date of publication: 29.04.2020 Bulletin 2020/18 (21) Application number: 18819655.4 (22) Date of filing: 22.06.2018

(51) International Patent Classification (IPC):  C09K 8/24(2006.01) E21B 21/06(2006.01) E21D 9/13(2006.01) E21B 21/00(2006.01) E21D 9/11(2006.01) (86) International application number: PCT/CA2018/050777 (87) International publication number: WO 2018/232532 (27.12.2018 Gazette 2018/52)

(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: KH MA MD TN (30) Priority: 23.06.2017 US 201762524361 P (71) Applicant: Canadian Energy Services L.P. Calgary, Alberta T2P 3J4 (CA)	(72) Inventors: SMITH, Carl Keith Calgary Alberta T3H 3S6 (CA) GAWRYLUK, Josh Turner Valley Alberta T0L 2A0 (CA) (74) Representative: Atkinson & Company Intellectual Property Limited  7 Moorgate Road Rotherham S60 2BF Rotherham S60 2BF (GB)