In areas of high oil saturation,the oil rests on a film of water spread over the surface.If the rock surface is preferentially water-wet and the rock is saturated with oil,water will imbibe into the smaller pores,displacing oil from the core when the system is in contact with water.In areas of high oil saturation, the oil rests on a film of water spread over the surface. If the rock surface is preferentially water-wet and the rock is saturated with oil, water will imbibe into the smaller pores, displacing oil from the core when the system is in contact with water