直流电场对岩心润湿性的影响研究

采用 Amoutt法详细分析研究了在外加电场作用下储层岩石润湿性的变化情况 ,并在此基础上进一步考查了电位梯度、电场作用时间和电场作用方向等电场参数对储层岩石润湿性的影响及其变化规律 .研究结果表明 :在外加直流电场作用下 ,可使储层岩石润湿性向亲水方向转化 ,电场方向对润湿性的改变方向和变化程度影响不大 ,但电位梯度和加电时间对润湿性的改变有很大影响 ,随着电位梯度和加电时间增加 ,储层岩石润湿性逐渐向强亲水方向转化 .同时 ,在外电场作用下使储层岩石孔隙孔道的连通性增强 ,油水流动阻力降低、相对渗透率和水驱油效率及原油采收率提高 .

Effect of DC Electric Field on the Wettability of Cores

Using Amott method, the effects of potential gradient, electric field effecting time, electric field effecting direction,product of electrolysis etc. on the wettability of nature cores are studied. The results show that, DC electric field makes the cores become hydrophilous, the direction and degree of the wettability change has little something to do with the electric field direction and potential gradient, but the wettability has great something to do with the electric field effecting time and the product of electrolysis (alkali). While the electric field effecting time is elasping, the extent of the wettability becomes wider. If the current intensity is excessive, the wettability will unexpectedly reverse. The changes of the weteability are caused by the effect of electric field on the characteristics and structures of matrix mineral and clay mineral. The DC electric field can improve the wettability of low permeability reservoir. The DC electric field can also increase the connectiviey of capillary system, reduce the flow resistance of oil, and increase waterflooding effeciency and recovery factor.