三维井地电阻率法异常响应特征增强算法模拟研究

从井地电阻率法满足的边值问题出发，利用有限元法实现了三维井地电阻率法的数值模拟，同时给出了异常电位水平导数的解析计算方法；模拟计算了多种不同情况下三维异常体模型的异常电位水平导数，详细分析了异常电位水平导数的极值与异常体边界对应关系的影响因素。当同时出现埋深不同的异常体时，中、深部异常体的井地电阻率法异常响应信号非常弱小，边界范围的轮廓模糊不清，应用归一化总水平导数法能够在一定程度上增强中、深部异常体的响应特征。

Started from the boundary value problem of borehole-to-surface resistivity method,the 3D numerical simulation of borehole-to-surface resistivity method with finite element method is realized,while the analytic algorithm of horizontal derivative for abnormal electric potential is given.The horizontal derivatives of abnormal potential from 3D abnormal body models are calculated in various different situations,and a detailed analysis on various influence factors associated the extreme values of horizontal derivatives with abnormal body boundaries is conducted.When the abnormal bodies are buried in different depths,the abnormal response signals of deeper abnormal body is extremely weak,and the bounding outline of abnormal response is unclear.So we introduce the normalized total horizontal derivative method which can enhance the response characteristics of the deeper abnormal body to some extent.