(19)

(11)

EP 2 850 275 A1

(12)

(43) Date of publication: 25.03.2015 Bulletin 2015/13 (21) Application number: 13791535.1 (22) Date of filing: 17.05.2013

(51) International Patent Classification (IPC):  E21B 17/03(2006.01) E21B 21/08(2006.01) E21B 21/01(2006.01) (86) International application number: PCT/US2013/041696 (87) International publication number: WO 2013/173785 (21.11.2013 Gazette 2013/47)

(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 (30) Priority: 18.05.2012 US 201261648867 P (71) Applicant: Smith International, Inc. Houston, TX 77073 (US)	(72) Inventors: MURRAY, William Tomball, TX 77377 (US) COLLETTE, Samuel Conroe, TX 77385 (US) (74) Representative: Ljungberg, Robert  Murgitroyd & Company Scotland House 165-169 Scotland Street Glasgow Strathclyde G5 8PL Glasgow Strathclyde G5 8PL (GB)