二维直流电阻率倾斜各向异性自适应有限元正演  

Adaptive finite element modeling of direct current resistivity in 2-D tilted anisotropy structures

作　　者：严波 韩波[2] 

机构地区：[1]湖南文理学院国际学院,湖南常德415000 [2]中国海洋大学"海底科学与探测技术"教育部重点实验室,山东青岛266100

出　　处：《石油物探》2017年第5期766-773,共8页Geophysical Prospecting For Petroleum

基　　金：国家自然科学基金青年基金项目(41604063)资助~~

摘　　要：提出了一种二维直流电阻率倾斜各向异性自适应有限元数值模拟算法,利用对偶加权后验误差估计因子指导网格自动细化过程,并在易于模拟起伏地形和倾斜界面等复杂构造的非结构三角网格上实现了这种算法。模拟了水平两层电阻率倾斜各向异性模型的直流视电阻率,并将其与解析解以及电阻率各向同性模型的直流视电阻率进行了比较,结果表明,除了电源点附近测点的有限元数值解误差较大外,其它测点处相对误差都在1%以内,且电阻率各向异性对视电阻率曲线的峰值和形态都有明显影响。二维电流密度矢量图能够很好地解释视电阻率曲线峰值和形态随电阻率各向异性倾角变化而变化的现象。In this paper,we propose an adaptive finite element （FE） numerical simulation algorithm for direct current （DC） resistivity in two-dimensional tilted anisotropy structures.This algorithm uses a dual weighting posteriori error estimation factor to guide the mesh auto- rustic refining process, and it is implemented on unstructured triangular elements that facilitate simulation of complex structures character- ized by undulating topography and tilted interfaces. We simulated the IX2 apparent resistivity of a two-layer resistivity tilted anisotropy model and compared it with the analytic solution and the DC apparent resistivity o{ the resistivity isotropy model.The results showed that the relative error of the finite element numerical solution in most measuring points was within 1 ~, the relative error of the measuring points near the power points was large, and the resistivity alaisotropy had a significant effect on the peak and shape of the apparent resistivi- ty curves.The phenomenon of the peak and the shape of the resistivity curves varying with the change in resistivity ailisotropy dip angles can be explained using a twcrdimensional current density vector diagram.

关 键 词：自适应有限元 非结构三角单元 后验误差估计因子 倾斜各向异性 

分 类 号：P631[天文地球—地质矿产勘探]