Research For Data Acquisition And Forward And Inverse Interpretation Of The Ultra-High Density Resistivity And Induced Polarization Method

The ultra-high density resistivity and induced polarization method is a practical eletrical exploration method with high efficiency. Compared with the conventional high density resistivity and induced polarization method, it avoids the single array distribution and collection coefficient, and obtains more information with same electrode arrangement and measurement time. The data amount is more than10times bigger than the conventional method, the inversion interpretation can approximate the actual geological structure condition better.Based on the works have done, this thesis put forward the ultra-high density resistivity and induced polarization method and researched on it systematically. It started from the theory of the ultra-high density resistivity and induced polarization method, focused on its data acquisition method, and formed tables of electrode arrangement data, then summarized the working range and features of this method. It studied the theory of multi-channel data acquisition in this method, and also the working requirements, working process and features for it. For the forward simulation and inversion imaging of the ultra-high density resistivity and IP method, the thesis started from the basic equations of stable current field,then derived its boundary problem and the variational problem, then solved this variational problem by using the finite element method based on continuous medium model. In order to accelerate the velocity of forward simulation, the Cholesky factorization with variable bandwidth compression storage is used to solve the stiffness matrix sparse linear equations. On the basis of forward simulation, it studied the least-square generalized linear inversion method of the IP data, the hybrid computation method of partial derivative matrix, and the solving method of linear inversion equation. In the end, it carried out the forward simulation and inversion imaging of some typical geoelectric model in pole-pole array, full-three-pole array and full-four-pole array of the ultra-high density resistivity and induced polarization method. Also, it proved the feasibility and applicability of the ultra-high density resistivity and induced polarization method by comparing and analyzing the response of different devices. With this thesis, It lays a solid foundation for the further application and popularization of the ultra-high density resistivity and induced polarization method.