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(11)

EP 3 585 974 A1

(12)

(43) Date of publication: 01.01.2020 Bulletin 2020/01 (21) Application number: 18758151.7 (22) Date of filing: 27.02.2018

(51) International Patent Classification (IPC):  E21B 29/00(2006.01) E21B 31/06(2006.01) E21B 37/00(2006.01) E21B 43/11(2006.01) E21B 23/04(2006.01) E21B 33/12(2006.01) E21B 29/06(2006.01) E21B 23/06(2006.01) E21B 29/02(2006.01) (86) International application number: PCT/US2018/019989 (87) International publication number: WO 2018/157144 (30.08.2018 Gazette 2018/35)

(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: MA MD TN (30) Priority: 27.02.2017 US 201715444099 (71) Applicant: Robertson Intellectual Properties, LLC Arlington, TX 76001 (US)	(72) Inventors: BOELTE, William, F. Arlington TX 76001 (US) ROBERTSON, Michael, C. Arlington TX 76001 (US) STREIBICH, Douglas, J. Arlington TX 76001 (US) (74) Representative: Barker Brettell LLP  100 Hagley Road Edgbaston Birmingham B16 8QQ Birmingham B16 8QQ (GB)