(19)

(11)

EP 2 788 577 A2

(12)

(88) Date of publication A3: 20.03.2014 (43) Date of publication: 15.10.2014 Bulletin 2014/42 (21) Application number: 12806782.4 (22) Date of filing: 07.12.2012

(51) International Patent Classification (IPC):  E21B 43/00(2006.01) E21B 43/16(2006.01) E21B 43/26(2006.01) (86) International application number: PCT/US2012/068379 (87) International publication number: WO 2013/086278 (13.06.2013 Gazette 2013/24)

(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: 08.12.2011 US 201161568279 P (71) Applicant: Saudi Arabian Oil Company Dhahran 31311 (SA)	(72) Inventors: NOUI-MEHIDI, Mohamed, Nabil Dhahran 31311 (SA) AL-KHALDI, Mohammed, H. Dhahran 31311 (SA) (74) Representative: Dauncey, Mark Peter  Marks & Clerk LLP 1 New York Street Manchester, M1 4HD Manchester, M1 4HD (GB)