中文摘要：

油气田注水开发过程中因地层压力变化而引起的自然电位异常主要用实验方法研究。目前，还不能从微观机理上揭示地层压力变化时电化学因素对自然电位的影响。利用孔隙介质的毛细管模型，导出了渗流场、离子流场和电流场的耦合关系，建立了描述地层压力变化对自然电位异常影响的数学模拟方法，数值计算了地层压力变化对自然电位的影响，定量分析了地层水矿化度、阳离子交换量和岩石孔隙度等因素对自然电位异常的影响。地层压力差越大，自然电位异常值越大。随着阳离子交换量的增大、孔隙度的增大和泥浆滤液黏度的减小，自然电位异常值增大。研究结果证实了流动电位的存在是地层压力引起储层自然电位异常的主要原因。

英文摘要：

The abnormal spontaneous potential caused by formation pressure is studied mainly by experimental method in waterflood development. At present, it is impossible in micro-mechanism to get the influence of electrochemical properties on spontaneous potential. According to capillary model in porous medium is used to derive the coupling relationships among percolation field, ion field and current field. And the mathematical simulation method is established to describe the influence of formation pressure on abnormal spontaneous potential. The influence of salinity of formation water, cation exchange capacity and porosity, etc. on spontaneous potential is analyzed quantitatively. The above results show that the bigger the formation pressure difference, the larger the spontaneous potential. The spontaneous potential increases with the increase of cation exchange capacity, porosity and decrease of mud filtrate viscosity. The obtained conclusion proves that the streaming potential is key factor to cause abnormal spontaneous potential.