(19)

(11)

EP 2 598 713 A1

(12)

(43) Date of publication: 05.06.2013 Bulletin 2013/23 (21) Application number: 11820469.2 (22) Date of filing: 22.08.2011

(51) International Patent Classification (IPC):  E21B 43/04(2006.01) E21B 33/12(2006.01) E21B 43/08(2006.01) (86) International application number: PCT/US2011/048660 (87) International publication number: WO 2012/027283 (01.03.2012 Gazette 2012/09)

(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: 23.08.2010 US 375977 P (71) Applicants: Services Pétroliers Schlumberger 75007 Paris (FR) FR  Schlumberger Holdings Limited Tortola 1110 (VG) GB NL  Schlumberger Technology B.V. (STBV) 2514 JG The Hague (NL) AL BG CZ DE DK GR HU IE IT LT NO PL RO SI SK TR  PRAD Research and Development Limited Road Town, Tortola 1110 (VG) AL AT BE CH CY EE ES FI HR IS LI LU LV MC MK MT PT RS SE SM  Schlumberger Technology Corporation Sugar Land, TX 77583 (US) IS

(72) Inventors: WASSOUF, Philip London Greater London W14 8QW (GB) JAIN, Samyak Stafford, TX 77477 (US) (74) Representative: Fortt, Simon Merton  Schlumberger Cambridge Research Ltd IP Law Department High Cross, Madingley Road Cambridge, CB3 0EL Cambridge, CB3 0EL (GB)