关键词: 声波振动, 接触角, 岩石表面润湿性, 原油采收率

Abstract: The influence of sound action on interfacial properties of crude oil/rock and water/rock interfaces has been investigated by the measurement of the contact angle of water on rock surface,flooding under sound action and theoretical analysis.The wettability of rock surface and the mechanism of water flooding under sound action have also been studied based on the theory of interfacial surface chemistry.The result shows that the wettability of rock surface was changed from water wettalbe into oil wettable due to the adsorption of polar components,such as asphaltene and resin fractions,after the rock was saturated with crude oil.The oil wettability of the rock surface could be decreased and the water wettability of the rock surface could be increased by sound vibration while the rock was immersed in water.The affection of the sound action on rock wettability works for both oil wettable and water wettable rocks.Therefore,the capillary resistance could be decreased.As the wettability of the rock surface was changed,the cohesion work of crude oil on the surface of rock was reduced obviously,so that the viscous force between the crude oil and the rock surface was reduced and the crude oil was easily removed from the rock surface,which made the oil recovery rate increased.The lower the permeability of the rock,the higher the oil recovery rate of water flooding was increased under sound vibration.

Key words: sound vibration, contact angle, wettability of rock surface, crude oil recovery