(19)

(11)

EP 1 934 287 A2

(12)

(88) Date of publication A3: 18.05.2007 (43) Date of publication: 25.06.2008 Bulletin 2008/26 (21) Application number: 06790733.7 (22) Date of filing: 25.09.2006

(51) International Patent Classification (IPC):  C08L 83/04(2006.01) C07F 7/08(2006.01) C09K 8/03(2006.01) (86) International application number: PCT/CA2006/001567 (87) International publication number: WO 2007/033489 (29.03.2007 Gazette 2007/13)

(84) Designated Contracting States: AT BE BG CH CY CZ DE DK EE ES FI FR GB GR HU IE IS IT LI LT LU LV MC NL PL PT RO SE SI SK TR Designated Extension States: AL BA HR MK RS (30) Priority: 23.09.2005 US 719597 P (71) Applicant: Trican Well Service Ltd. Calgary, Alberta T2P 4G8 (US)	(72) Inventor: ZHANG, Kewei Calgary, Alberta T2P 4G8 (CA) (74) Representative: Elend, Almut Susanne et al Venner Shipley LLP 20 Little Britain London EC1A 7DH London EC1A 7DH (GB)