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(11)

EP 3 797 208 A1

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(43) Date of publication: 31.03.2021 Bulletin 2021/13 (21) Application number: 18929831.8 (22) Date of filing: 06.08.2018

(51) International Patent Classification (IPC):  E21B 33/064(2006.01) E21B 34/00(2006.01) E21B 34/04(2006.01) (86) International application number: PCT/US2018/045387 (87) International publication number: WO 2020/032920 (13.02.2020 Gazette 2020/07)

(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 (71) Applicant: Halliburton Energy Services Inc. Houston, Texas 77032-3219 (US)	(72) Inventors: FOX, Guy R. Houston, Texas 77066 (US) DERR, Douglas N. Houston, Texas 77066 (US) CRAMM, Carl J. Houston, Texas 77066 (US) CUTHBERT, Andrew J. Houston, Texas 77066 (US) (74) Representative: McWilliams, David John et al Withers & Rogers LLP 4 More London Riverside London SE1 2AU London SE1 2AU (GB)