(19)

(11)

EP 2 668 525 A2

(12)

(88) Date of publication A3: 20.12.2012 (43) Date of publication: 04.12.2013 Bulletin 2013/49 (21) Application number: 12749990.3 (22) Date of filing: 22.02.2012

(51) International Patent Classification (IPC):  G01V 11/00(2006.01) G01V 3/26(2006.01) G01V 1/40(2006.01) E21B 49/08(2006.01) (86) International application number: PCT/US2012/026132 (87) International publication number: WO 2012/116072 (30.08.2012 Gazette 2012/35)

(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 (30) Priority: 23.02.2011 US 201161445682 P (71) Applicants: Services Pétroliers Schlumberger 75007 Paris (FR) FR  Schlumberger Holdings Limited Tortola 1110 (VG) GB NL  Schlumberger Technology B.V. 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 Tortola 1110 (VG) AL AT BE BG CH CY EE ES FI HR IS LI LU LV MC MK MT PT RS SE SK SM

(72) Inventor: GOODWIN, Anthony Robert Holmes Sugar Land, Texas 77478 (US) (74) Representative: Ford, Michael Frederick  Schlumberger Cambridge Research Limited High Cross Madingley Road Cambridge CB3 0EL Cambridge CB3 0EL (GB)