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EP 2 225 435 A1

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(43) Date of publication: 08.09.2010 Bulletin 2010/36 (21) Application number: 07865030.6 (22) Date of filing: 30.11.2007

(51) International Patent Classification (IPC):  E21B 23/00(2006.01) E21B 33/13(2006.01) E21B 33/12(2006.01) E21B 49/00(2006.01) (86) International application number: PCT/US2007/086132 (87) International publication number: WO 2009/070175 (04.06.2009 Gazette 2009/23)

(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 MT NL PL PT RO SE SI SK TR Designated Extension States: AL BA HR MK RS (71) Applicant: Welldynamics, Inc. Spring, TX 77386 (US)	(72) Inventors: SCHRADER, Kirby, G. Magnolia TX 77386 (US) CURINGTON, Alfred, R. The Woodlands, TX (US) KANNAN, Bharathwaj Spring TX 77380 (US) (74) Representative: Bennett, Adrian Robert J.  A. A. Thornton & Co. Mechanical 235 High Holborn London WC1 V7LE London WC1 V7LE (GB)