井地电位2.5维有限元数值模拟异常分析  

ANOMALOUS ANALYSIS OF THE 2.5-D FINITE ELEMENT NUMERICAL SIMULATION OF BOREHOLE-GROUND ELECTRICAL METHOD

作　　者：戴前伟[1,2] 侯智超[2] 王洪华[2] 

机构地区：[1]中南大学有色金属成矿预测教育部重点实验室地球科学与信息物理学院,长沙410083 [2]中南大学地球科学与信息物理学院,湖南长沙410083

出　　处：《物探化探计算技术》2013年第4期457-462,373,共6页Computing Techniques For Geophysical and Geochemical Exploration

摘　　要：从井地电位法满足的边值问题出发,利用有限元推导了井地电位2.5维的详细解法,并编制了相应的程序。然后利用该程序对一水平层状的地电模型进行了正演计算,并与解析解做了对比分析,验证了程序的正确性和有效性。在此基础上对均匀介质中分别存在高阻板、低阻板以及高阻板与低阻板同时存在的模型,进行了正演计算,得到了视电阻率拟断面图及点电流源在不同深度的视电阻率曲线分布图。结果表明,该方法能够对地下介质进行有效的探测,能够精确地确定异常体上边界、下边界的埋深位置。Starting from the boundary value problem of borehole-ground electrical method,we derived the 2.5-D detailed solution and provided the corresponding program with finite element method.The program calculates the forward results of a horizontally layered ground model and compares with the analytical solution to verify the correctness and effectiveness of the program.On this basis,we got the forward calculation results of models of high or low resistance plate and both of them existed in homogeneous medium,which included the pseudosection map of apparent resistivity and the curves of apparent resistivity with point current source in different depths.The results show that this method can probe the subsurface effectively and determine the upper boundary and the lower boundary of the anomalous body accurately.

关 键 词：井地电法 有限元法 正演 视电阻率 点电流源 

分 类 号：P631.3[天文地球—地质矿产勘探]