为了进一步认识泥质对岩石宏观电性的影响规律,本文利用非规整三维逾渗网络模型,通过数值模拟研究了不同矿化度下泥质对岩石电性影响的规律.模拟结果表明:在中低矿化度下,泥质对岩石导电整体上呈现减阻作用,随着泥质含量的增加,电阻率降低的速度减慢;中等矿化度下泥质的减阻效果明显弱于低矿化度下的减阻效果;在高矿化度下泥质对岩石导电整体上呈现增阻作用.在高矿化度、高含水饱和度下泥质对岩石电性的影响较小.泥质起减阻、增阻作用的具体矿化度范围取决于储层的孔隙度、连通性以及地层温度等特性。
In order to further understand shale effects on rock electrical properties under different conditions, we use an irregular three dimensional percolation network model to study the effects of shale on rock electrical properties under different salinity through numerical simulation. The simulation results show that under middlelow salinity the shale effect on rock electrical properties is manifested by resistivity reduction. With the increasing of the shale content, the speed of the resistivity decreasing is slowing. The effect under middle salinity is weaker than that under low salinity. Under high salinity the shale effect on rock electrical properties is shown by increasing resistivity. However under the condition of high salinity and high water saturation the effect is little. The salinity ranges for the shale to reduce or increase resistivity depend on the reservoir properties such as porosity, connectivity, temperature and so on.