基于感度分析的井-地视电阻率成像及野外应用

Borehole-surface resistivity tomography and field application based on sensitivity analysis

通过对电法勘探中常用的温纳和二极装置的感度分布特征的分析,本文提出了根据感度分布规律对两种电极装置在井-地电阻率法成像中所获得的视电阻率数据进行标记的方法.通过构建含断裂带的三维地电模型,并采用有限单元法模拟计算测量结果,对比已知模型,验证了该方法的可靠性.利用温纳和二极装置,分别针对野外钻孔进行了井内和井-地高密度电阻率成像(ERT),分析了不同电极装置对成像结果的影响.所得结果初步揭示了钻孔周围几十米空间内的地电结构分布特性,取得了良好的应用效果.

The sensitivity distribution characteristic of wenner and pole-pole array which was widely used in direct current exploring have been researched.The paper presents a method of apparent resistivity position recording in borehole-surface resistivity tomography based on sensitivity distribution analysis.The reliability of 3-D resistivity model having fault zone and the simulation results of the finite element method were compared and verified with known model.Different array such as wenner and pole-pole array have been used to detected field borehole through borehole and borehole-surface high density resistivity tomography（ERT）.We discussed the impact to the detecting result which caused by different measure array.The result confirms that the constructed apparent resistivity model is effective and can detect fractures and fault information around the borehole in the tens of meters.