(19)

(11)

EP 4 519 535 A1

(12)

(43) Date of publication: 12.03.2025 Bulletin 2025/11 (21) Application number: 23724358.9 (22) Date of filing: 04.05.2023

(51) International Patent Classification (IPC):  E21B 33/124(2006.01) E21B 36/00(2006.01) (52) Cooperative Patent Classification (CPC): E21B 33/124; E21B 36/00 (86) International application number: PCT/GB2023/051185 (87) International publication number: WO 2023/214175 (09.11.2023 Gazette 2023/45)

(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 ME MK MT NL NO PL PT RO RS SE SI SK SM TR Designated Extension States: BA Designated Validation States: KH MA MD TN (30) Priority: 04.05.2022 US 202263338052 P (71) Applicant: BiSN Tec Ltd 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)