储层岩石流动电位的电化学影响因素

利用储层岩石的流动电位特性描述油藏的流动特性已引起地球物理领域的关注。依据多孔介质中的双电层模型与毛管电化学理论,建立了渗流场、离子流场和电流场的耦合关系,数值模拟了泥质砂岩储渗特性和电化学因素对流动电位耦合系数的影响。结果表明:当考虑储层岩石中存在浓差极化效应时,流动电位耦合系数的绝对值随溶液浓度、阳离子交换量、孔隙度和渗透率的增大而增大;浓差极化效应对流动电位具有放大作用。

A STUDY OF THE INFLUENCES OF ELECTROCHEMICAL FACTOR ON STREAMING POTENTIAL IN RESERVOIR ROCK

In the field of geophysical exploration,great attention has been paid to the utilization of the streaming potential characteristics in reservoir rock to describe the flow characteristics of the reservoir.According to the electrical double-layer model and the electrochemical theory,the authors derived the coupling relationships between flow field,ion field and current field based on the capillary model.The influences of pore structure parameters on the coupling coefficient of streaming potential were obtained by numerical simulation.The results show that,when the influence of the concentration polarization effect on streaming potential is considered,the absolute value of coupling coefficient of streaming potential increases with the increasing solution concentration,cation exchange capacity,porosity and permeability.In addition,the concentration difference polarization amplifies the streaming potential.