If the rock surface is preferentially oil-wet,even though it may be saturated with water,the core will imbibe oil into the smaller pores,displacing water from the core when it is contacted with water.Thus,a core saturated with oil is water-wet if it will imbibe water and,conversely,a core saturated with water is oil-wet if it will imbibe oilIf the rock surface is preferentially oil-wet, even though it may be saturated with water, the core will imbibe oil into the smaller pores, displacing water from the core when it is contacted with water. Thus, a core saturated with oil is water-wet if it will imbibe water and, conversely, a core saturated with water is oil-wet if it will imbibe oil