The Study On Tridimensional Numerical Simulation Of Resistivity And Its Application

The research of tridimensional numerical simulation of resistivity method is conducted with the finite difference based on the basic differential equation for DC method. The achievement of tridimensional numerical simulation of resistivity method provides a powerful support for studying the electrical irregular rule of complex geological structure, and it also gives a preferable basis for recognizing observational data and instructing the explain of inversion.This article mainly introduces the study on tridimensional numerical simulation of resistivity and its application. The whole text contains three parts:The first part introduces the principle of the tridimensional finite difference of resistivity in detail, and accesses a forward calculation of the horizontal layered model and the vertical contact surface model with the simulation technology. The results show high accuracy of the procedure. All these validate the correctness of this arithmetic. Then simulatively calculate the apparent resistivity profiles of geoelectric models of some different tridimensional geological structures such as cube, tabular body, combinations, ridge terrain and valley terrain based on the forward procedure. The simulation results above make us acquire a better knowledge of irregular features of apparent resistivity, and also provide reference for practical work outdoors.The second part first studies the power of two-dimensional inversion method to resolve multi-tridimensional bodys in the deep parts. When the total depth of embedment of the center of two parallel abnormal bodies is less than the distance of them, the two-dimensional inversion method could resolve these two abnormal bodies, but it is less able to resolve two vertical and superimposed abnormal bodies. By the two-dimensional inversion programn and ratio method, then respectively correct the data of the resistivity of geoelectric model under the condition of two-dimensional ridge terrain and valley terrain and compare the effects of topographic correction. As a result, the two-dimensional programn produces little effect on the topographic correction. While on the contrary, the ratio method creates a greater effect on the data correction of resistivity of the two-dimensional abnormal bodies than on that of the tridimensional abnormal bodies.The third part is about the anisotropy analysis of apparent resistivity at seismic stations. Adopt numerical simulation of the specific model, and sum up how the parameter changes in the non-uniform bodies influence the anisotropy changes in the apparent resistivity, and compare with the actual phenomena observed at seismic stations. The simulation results prove that the non-uniform bodies underground can bring on anisotropy changes in the apparent resistivity.