(19)

(11)

EP 2 076 652 A1

(12)

(43) Date of publication: 08.07.2009 Bulletin 2009/28 (21) Application number: 07823098.4 (22) Date of filing: 02.10.2007

(51) International Patent Classification (IPC):  E21B 10/64(2006.01) E21B 7/20(2006.01) (86) International application number: PCT/FI2007/000237 (87) International publication number: WO 2008/040837 (10.04.2008 Gazette 2008/15)

(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 (30) Priority: 03.10.2006 FI 20060884 (71) Applicant: Turun Ammattikorkeakoulu 20521 Turku (FI)	(72) Inventor: LEHTONEN, Jouko FI-20100 Turku (FI) (74) Representative: Suominen, Kaisa Liisa  Turun Patenttitoimisto Oy, P.O.Box 99 20521 Turku 20521 Turku (FI)