储层岩石周期性电渗流特性的微观机制

以双电层电位理论和电渗流动的动量方程为基础，结合储层岩石平行毛管束模型，推导出岩石孔隙内周期性电渗流的解析式，揭示了储层中电渗效应的微观机制，分析了非密闭储层岩石中宏观电渗Darcy速度及密闭储层中电渗压力系数频散特性的影响因素．数学模拟结果表明:储层岩石孔隙中，周期性电渗流速度剖面在频率较高时呈“波浪”状；孔隙度越大，电渗Darcy速度模值越大，其相位也越大，而电渗压力系数数值越小．储层岩石的溶液浓度越小或阳离子交换量越大，电渗Darcy速度模值和电渗压力系数数值越大，但对电渗Darcy速度的相位没有影响．

Microscopic Mechanism of Periodical Electroosmosis in Reservoir Rocks

Based on the electric double layer (EDL) theory and the momentum equation governing the electroosmosis flow, an analytical solution to the periodical electroosmosis with a parallel straight capillary bundle model of reservoir rocks to reveal the microscopic mechanism of the electroosmotic flows in rocks was presented.The theory shows that both frequency dispersion characteristics of the macroscopic electroosmotic Darcy velocity in unsealed rocks and the electroosmotic pressure coefficient in sealed rocks depend on the porosity and electrochemical properties of reservoir rocks. The mathematical simulation indicates that the distribution of the periodical electroosmotic velocity is wave like in the rock pore. The greater the porosity, the greater electroosmotic Darcy velocity and the smaller electroosmotic pressure coefficient are generated. The module value of the electroosmotic Darcy velocity and the electroosmotic pressure coefficient increase with the decreasing solution concentration or the increasing cation exchange capacity without affecting the phase of the electroosmotic Darcy velocity.