Abstract: This paper shows that the "nonhydrocarbon+bitumen" is the key matter which affects the surface wettability of an oil reservoir; When its content arrives at a certain value, the surface wettability of narrow constrictions in the pores of the reservoir may convert into oil-wet. However, when the surface of pore throat is oil-wet, the determination of the wettability of rock sample is dependent upon the amount of the water saturation. It is oil-wet when the water saturation is below 30%, and water-wet when it is over 40%. It is shown that the wettability of the rock is gradually transformed from oil-wet to water-wet as the water injection is goiog on.

摘要： 本文认为原油中“非烃+沥青质”是影响油层岩石表面润湿性的关键因素,当其含量达到一定数值时,则油层内的含油孔道岩石表面润湿性可以改变成亲油。当含油孔道岩石表面亲油时,其润湿性受含水饱和度的影响,即含水饱和度低于30%时是亲油、高于40%时是亲水。指出油田随注水开发时间的延长,油层的润湿性将由亲油逐渐改变成亲水。