(19)

(11)

EP 4 248 055 A1

(12)

(43) Date of publication: 27.09.2023 Bulletin 2023/39 (21) Application number: 21811447.8 (22) Date of filing: 18.11.2021

(51) International Patent Classification (IPC):  E21B 29/02(2006.01) (52) Cooperative Patent Classification (CPC): E21B 29/02 (86) International application number: PCT/GB2021/052990 (87) International publication number: WO 2022/106826 (27.05.2022 Gazette 2022/21)

(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: 23.11.2020 GB 202018390 (71) Applicant: BiSN Tec Ltd Birchwood Warrington Cheshire WA3 6DE (GB)	(72) Inventor: CARRAGHER, Paul Warrington Cheshire WA3 6DE (GB) (74) Representative: Forresters IP LLP  Skygarden Erika-Mann-Straße 11 80636 München 80636 München (DE)