(19)

(11)

EP 2 800 862 A2

(12)

(88) Date of publication A3: 30.05.2014 (43) Date of publication: 12.11.2014 Bulletin 2014/46 (21) Application number: 13700803.3 (22) Date of filing: 05.01.2013

(51) International Patent Classification (IPC):  E21B 19/22(2006.01) (86) International application number: PCT/US2013/020421 (87) International publication number: WO 2013/103920 (11.07.2013 Gazette 2013/28)

(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 (30) Priority: 05.01.2012 US 201261583230 P (71) Applicant: National Oilwell Varco, L.P. Houston, Texas 77036 (US)	(72) Inventors: GOODE, John E. Fort Worth, Texas 76140 (US) LU, Mike Xiaolei Arlington, Texas 76013 (US) (74) Representative: Howe, Steven  Reddie & Grose LLP 16 Theobalds Road London WC1X 8PL London WC1X 8PL (GB)