Forward Modeling Study Of High-density Resistivity Method

The high-density resistivity method (High-density resistivity method) based on the differencesconductivity of rock, soil and other media a conduction current distribution as a basis, the byartificial current field is applied, in order to achieve the research underground electrical prospectingmethod. Have been more widely used in the study of hydrology, coalfield, engineering geology andtectonic.In the high-density resistivity method, the forward problem of high-density resistivity methodis to obtain the underground high density electric field distribution by knowing the conditions of theearth model and the initial-boundary conditions. One of the prerequisites for high density inversionresistivity method is accurate and complete forward problem by finding out fast algorithm. So, wemust first carry out the study of forward problem of high density resistivity method prior to thestudy of inverse problem of high-density resistivity method.Due to the complexity of the electric field, only when the individual is very simple, it can haverules body. While in most other electric models, it is generally difficult to obtain the analyticalsolutions. Their approximate numerical solution can only be obtained by numerical calculation. Inorder to solve complex electrical model simulation of the electric field of high-density resistivitymethod, the author has read a large number of domestic and foreign articles on forward numericalsimulation, by using the finite difference method, the author has programmed the forward modelingprocedures of a high-density resistivity method dimensional, analysis and summary of differentmodels.In the case of two-dimensional geoelectric section of point sources, the Fourier transform willbe going along the y direction, thereby introducing the transformation potential of the wavenumberdomain, and thus simplified potential Differential can be got, with differential equations replacingDifferential. Based on traditional mixed boundary conditions as constraints, optimization measuresare used for solving linear equations. In this way the transformation potential of the wave numberdomain is got, thus apparent resistivity values corresponding to the type of apparatus are obtained.Compared with the analytical solution, the vertical contact zone model has better accuracy and running speed, which has satisfied the initial validation of the feasibility and correctness of thealgorithm. Low-resistivity body and the level of high impedance model are calculated, forwardcalculation results of the program also is compared with foreign Pilisecky A and Knight R’sresearch result to further verify the correctness of the forward procedure. In the case of upright lowresistivity and high impedance vertical plate-like body model, different devices finite differenceforward modeling are applied. Low impedance and high impedance arranged on the horizontaldirection, double low resistance arrangement, and dual high impedance arranged electricalanomalies are tested by the forward modeling, as well as forward modeling in high in upper verticaldirection, on low, double high impedance and the double low resistance abnormal body. At last theirresults are compared and analyzed, and with its apparent resistivity inversion, it is obvious tounderstand the law of different electrical abnormalities resolution.