摘要
本项研究应用两电极法扫频测量了22块岩样在油驱水过程中电阻抗的变化．实验表明，在低频段（100Hz～10MHz）岩石的电阻抗虚部能较好地反映岩石含水饱和度的变化．岩石的界面极化频率及其对应的电阻抗实部、虚部与岩石的含水饱和度有较密切的关系，可以用来确定岩石的含水饱和度．岩样阻抗的实部和虚部的Argand图中的低端临界频率随着含水饱和度的变化而变，这表明低端临界频率不仅取决于岩石的特征长度（其中k为岩石的渗透率，Φ为岩石的孔隙度）．本文应用一个等效电路来说明观察到的现象，并预计有多个界面极化频率存在．
The impedance of 22 sandstone samples saturated with oil and water were measured with the two electrode method. Experiments show that the reactive part of impedance may respond well to the water saturation of rock in the frequency range 100Hz～10MHz. The maximum reactance and the interfacial polarization frequencics are found to be linear to water saturation. This founding can be a new method to determine the water saturation of rock. The lower critical frequency is found to vary with water saturation, but a not very clear relationship is found with the characterishc length of rock. An equivalent circuit is used to explain the dispersive behaviors of rock. More than one interfacial polarization frequency in an impedance Argand plot are predicted and can be observed if the measurement frequency range is wide enough.
出处
《地球物理学进展》
CSCD
1999年第1期93-103,共11页
Progress in Geophysics
