岩石复电阻率测量中的电极效应  

Electrode Effect in Rock Complex Resistivity Measurement

作　　者：童小龙 严良俊[1] 郭琦 TONG Xiao-long;YAN Liang-jun;GUO Qi(Yangtze University,Key Laboratory of Exploration Technologies for oil and Gas Resources,Wuhan 430100,China)

机构地区：[1]长江大学油气资源与勘探技术教育部重点实验室,武汉430100

出　　处：《科学技术与工程》2020年第13期5046-5051,共6页Science Technology and Engineering

基　　金：国家重点研发计划(2018YFC0603302)。

摘　　要：复电阻率是电磁勘探描述地下岩石电性的重要参数之一。根据电磁勘探频段,实验室内复电阻率测量的低频段通常达到10-2 Hz。为避免测试电极与岩石的宏观结构形成电极极化影响岩石微观结构的研究,通过电化学理论结合复电阻率实验研究了不同电极材料对流体、岩石的复电阻率测试中的电极极化特性。结果表明,测试岩石在低频段容易受以物质传递为主的电极极化影响;电极极化同时受电极材料、电极附近流体矿化度和温度、被测岩石阻抗等因素的影响;最后,分析和讨论了减小或消除电极极化影响的方法,为准确测量岩石复电阻率并用于微观结构分析提供了理论和实验基础。Complex resistivity is one of the important parameters for electromagnetic exploration in describing the electrical properties of underground rocks.Taking into account electromagnetic exploration frequency range,complex resistivity measurements in the laboratory are made to as low as 10-2 Hz.To avoid the influence of the rock’s microstructure by the electrode polarization of the macrostructure between electrode and rock,the electrode polarization characteristic of different electrode materials to electrolyte and rock was investigated in electrochemical theory and complex resistivity experiment.Results show that the test rock was easily affected by electrode polarization,which was dominated by material transfer in the low frequency band,while electrode polarization was affected by the electrode material,salinity,and temperature of fluid near the electrode,the measured rock impedance,and other factors.Finally,the method to reduce or eliminate the effect of electrode polarization were analyzed and discussed,which provides the theoretical and experimental basis for accurately measuring complex resistivity and studying microstructure of rock.

关 键 词：电磁勘探 复电阻率 电极极化 岩石物理 

分 类 号：P319[天文地球—固体地球物理学]