Wettability Alteraion and Imbibition Effects in Steam Recovery from Matrix Blocks in Fractured Reservoirs

C13 WETTABILITY ALTERATION AND IMBIBITION EFFECTS IN STEAM RECOVERY FROM MATRIX BLOCKS IN FRACTURED RESERVOIRS Abstract 1 Imbibition in matrix blocks is one of the most important mechanisms for oil recovery from fractured reservoirs. However imbibition is impeded if the matrix blocks are oil-wet. The alteration of wetting from oil-wet to water-wet enhances the recovery. Contact angle measurements show that steam (high temperature) alters the wetting properties. Therefore steam injection has been suggested as an alternative for water drive. Still the mechanism of thermally induced wetting changes remains unclear. Moreover a change in contact angle only indicates the possibility of