Abstract: The effect of brine injection rate on spontaneous imbibition behavior and recovery of sandstone is studied, and the ultimate recovery comparison between static imbibition and dynamic imbibition is conducted. The results show that with the increase of brine injection rate, the dynamic imbibition recovery increases and decreases, rapidly, and then tends to be stable, with mono-peak variation in oil recovery and brine injection rate. The fact that dynamic imbibition recovery is lower than static one indicates that spontaneous imbibition of sandstone needs enough time to full exert capillary imbibition in low permeability reservoir. So the injection rate should be low, and measures including intermittent and cyclic injection and production should be adopted in order to increase the spontaneous imbibition recovery.

Key words: spontaneous imbibition, outcrop sandstone, injection rate, recovery, water-wet