基于径向剖分的井地三维有限元电阻率与极化率模拟  

3-D FEM modeling of borehole-ground resisitivity and polarizability based on radial subdivision

作　　者：黄俊革[1] 李林杰[1] 农观海[1,2] 闫怀超 高文利[3] 林振洲[3] 

机构地区：[1]上海应用技术学院城市建设与安全工程学院,上海201418 [2]桂林理工大学地球科学学院,桂林541004 [3]中国地质科学院地球物理地球化学勘查研究所,河北廊坊065000

出　　处：《成都理工大学学报（自然科学版）》2015年第6期753-761,共9页Journal of Chengdu University of Technology: Science & Technology Edition

基　　金：中国地质调查局地质调查工作项目(1212011120196)

摘　　要：采用径向剖分的有限元法对井地三维电阻率法进行数值模拟,以适应不同观测装置对数值模拟的要求。以井口为中心,将区域在环钻孔方向以45°夹角均匀剖分为八等分,再在直径方向上等距离剖分。径向剖分形成的单元呈环形分布,更符合井中电场的分布规律。与这种剖分相对应,设计了以井口为中心布置4条放射状测线("米"字形)的井地观测装置,解决了井旁地质体位置未知的情况下难以确定观测方向的问题。通过对典型的地质模型进行有限元正演模拟计算,结果表明径向剖分数值模拟方法是可行的、准确的;以这种井地观测方式探测位置未知的地质体是行之有效的。In order to fit different detecting installations, this paper makes 3-D modeling of the borehole-ground resisitivity and polarizaEility based on the radial division. Taking the well mouth as the centre, the region is equably divided into 8 sectors by 4 radial lines on the ground with the angle of 45° between two lines. Each sector is divided by a regular distance on radial line. The radial subdivision cells present a circular form, which is more coincidental with the distribution of an electric field. The paper designs the borehole-ground observation installation by setting 4 radial survey lines taking the well mouth as the center, thus, the surveying direction can be set under the unknown geologic bodies. The calculating of typical models shows that the subdivision method is correct and feasible. The surveying method by arraying around wells to detect the unknown position of geologic bodies is effective.

关 键 词：井地 径向剖面 有限元 电阻率 极化率 

分 类 号：P631.3[天文地球—地质矿产勘探]