陈延军 张智韬 仵杰

摘   要：岩石电各向异性以电导率张量表征，实验室中多采用四极法与六极法测得岩石电导率，但难以一次实验完全获得电导率张量的9个分量，若多次实验易造成较大的测量误差.为此本文基于文献研究成果，针对方样岩芯设计电导率张量测量仪，该方案也适用于柱塞岩芯.通过氮气驱替完全水饱的岩芯，温控系统和围压控制系统控制岩芯夹持器内部的温度和压力，可运用上位机控制电极测量不同含水饱和度时岩芯电导率张量的9个分量.该仪器亦可用于柱塞岩芯的岩电实验，通过测得的电导率数据，确定阿尔奇公式的未知系数. 通过理论与实验数据分析，验证了该电导率张量测量仪设计方案的可行性.

关键词：电各向异性;电导率张量;阿尔奇公式;电阻率指数

Abstract：The electrical anisotropy of rock is characterized by conductivity tensor. The four-pole method and six-pole method are mostly used to measure rock conductivity in the laboratory，but it is difficult to fill the nine components of conductivity tensor in one experiment. And multiple experiments are easy to cause large measurement errors. For this reason，based on the existing document，this paper designs a conductivity tensor measuring instrument for square sample cores. This solution is also suitable for plunger cores. The completely water-saturated core is replaced by nitrogen. The temperature control system and the confining pressure control system control the temperature and pressure inside the core holder. The upper computer control electrode can be used to measure the core conductivity tensor at different water saturations. The instrument can also be used for rock electrical experiments of plunger cores. Through the measured conductivity data，the unknown coefficients of Archies formula can be determined. Through the analysis on theoretical and experimental data，the feasibility of the design scheme of the conductivity tensor measuring instrument is verified.

Key words：electrical anisotropy;conductivity tensor;Archie formula;resistivity index

岩石物理参数测量是岩石物理学的重要内容，也是测井学科的基础.针对不同油田岩芯岩性、物性、含水性不同的特点，用岩电实验进行地层岩电机理分析研究，对各储层参数变化规律进行探讨，确定不同含水矿化度下岩石电阻率变化以及阿尔奇公式参数变化规律，可以提高解释精度并且对水饱模型优选及参数的正确选取提供理论依据[1-8]. 一般的测量仪工作频率为几赫兹到1兆赫兹，在不同储层环境下，可测量岩芯的电导率、介电常数、流体饱和度和岩芯结构参数.现有的电阻率测量仪器中，Noureddine等人[9-10]利用敏感交流电桥中的搜索线圈……