(19)

(11)

EP 4 392 640 A1

(12)

(43) Date of publication: 03.07.2024 Bulletin 2024/27 (21) Application number: 22861934.2 (22) Date of filing: 22.08.2022

(51) International Patent Classification (IPC):  E21B 25/16(2006.01) E21B 25/04(2006.01) E21B 44/06(2006.01) E21B 25/02(2006.01) E21B 34/08(2006.01) E21B 49/02(2006.01) (52) Cooperative Patent Classification (CPC): E21B 25/02; E21B 47/095 (86) International application number: PCT/US2022/041023 (87) International publication number: WO 2023/027981 (02.03.2023 Gazette 2023/09)

(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: 23.08.2021 US 202163236108 P (71) Applicant: Boart Longyear Company Salt Lake City Utah 84119 (US)	(72) Inventor: DRENTH, Christopher L. Callander, Ontario P0H 1HO (CA) (74) Representative: Lincoln IP  4 Rubislaw Place Aberdeen AB10 1XN Aberdeen AB10 1XN (GB)