| The frequency domain resistivity exploration method(FDIP) is one of the important methods of geophysical exploration, it is the physical basis of the frequency domain electric current of rock and ore field response abstract physical model of frequency domain Cole-Cole resistance current grid field response is induced polarization method in the point source current field in time domain(TDIP),and an electrical prospecting method based on the development of TDIP. The frequency domain resistivity method is studied in a single frequency or multi frequency(the frequency spectrum) of the AC electric field, the response characteristics of the observation and analysis of earth medium amplitude, the artificial source AC electric field polarization effect, and the inversion and the underground medium parameters on structural seismic imaging quality data measured in the field. According to the practical exploration of the use of different observation frequency, the frequency domain resistivity exploration methods can be divided into phase induced polarization,dual frequency induced polarization method and spectrum induced polarization method. The 4 Cole-Cole spectrum ipmethod true spectral parameters grid optimization inversion has so far failed to solve, so the phase induced polarization,dual frequency induced polarization method of the frequency domain resistivity exploration is still the two most common forms of law application, but also the most stable electrical prospecting technology. The frequency domain resistivity prospecting exploration depth, the IP effect is obvious, the working efficiency is high, especially for disseminated minerals and sulfide deposit reflects the unique advantage to separate the effective exploration, mine area caused by abnormal and non ore induced anomaly,has been widely used in geophysical prospecting of metal, non-metallic minerals, and various coal and Engineering exploration..At present, the technology of the frequency domain resistivity method is still lagging behind the level of development of the interpretation of the data rate in the frequency domain resistivity prospecting instrument. The main reason is that there are the frequency domain resistivity exploration has two difficult problems need to besolved: one is the problem of distortion and improve the effect of topography,complex geological body resistivity value, two fast 2.5 dimensional optimization inversion of IP effect parameters and fast computation. These two problems will directly affect the frequency domain resistivity exploration data processing and interpretation level. Based on the previous achievements, research on these two problems, as follows:1 In the forward numerical modeling, is presented in section triangle unit under the condition of rolling topography, complex, continuous variation of conductivity within each block, the 2.5 dimensional finite element numerical simulation of the frequency domain resistivity method. Compared to the conventional single rectangular or triangular mesh generation method, without increasing the number of grid nodes under the condition of using the rectangle, triangle mesh simulation of topography and complex geoelectric model, this simulation can simulate the actual field topographic conditions, and complex form of underground medium. In the numerical modeling of induction, analysis, summarized the apparent resistivity, induced polarization characteristics of various common measuring device, provides a theoretical understanding of distortion rate of terrain environment of complex resistivity data, as well as 2.5 dimensional terrain with the frequency domain resistivity inversion method provides a foundation for numerical modeling calculation.2 In the linear inversion method based on the previous achievements, the linear least square inversion method based on smooth model. In this paper, the idea is to join the grid, parameter model of the prior information and the smoothness of the grid factor matrix in the linear inversion equation of conventional, so as to avoid the uneven due to the irregular sparse grid and complex physical parameters distortion caused by physical field, the inversion calculation convergence speed faster, more accurate modeling. In the model the analysis of numerical examples and examples,the iteration inversion algorithm is generally not more than 10 times, the iterative inversion error of the theoretical model can reach less than 0.3%, the iterative inversion error of the measured data can reach 2%, the profile of 60 electrodes, 2400 data retrieval time is less than 200 s. Through the practical application of the two projects show that this method has obvious effect, and has a high practical value.3 According to the characteristics of changes in the same direction with the polarization parameters of the frequency domain resistivity method and induced polarization effect parameters of time domain induced polarization method in this paper, the rate of phase dispersion rate and parameters of the metal factor design forpolarization time domain IP Seigel polarization theory of the rate parameters, which is one of the experimental exploration and the innovation point. And put forward the 2.5dimensional finite element method with topography, the phase dispersion rate, smooth metal factor model of linear least squares optimization inversion and imaging, which has successfully solved the 2.5 dimensional the frequency domain resistivity exploration method of IP inversion effect parameter problem.In this thesis, mainly for data processing and interpretation of the frequency domain resistivity method, and the measured data distortion, fitting accuracy, computation speed as the research content. Complex resistivity method in 2.5 dimensional numerical modeling, the cutting triangular element, rugged terrain, complex continuous variation of conductivity within each block, the 2.5 dimensional finite element numerical modeling of the frequency domain resistivity method. In the numerical simulation analysis, and sums up the apparent resistivity and induced polarization characteristics of various common measuring device, and the influence of topography on the rate of the frequency domain resistivity exploration; in the inversion and imaging, proposed 2.5 dimensional smooth terrain model with complex resistivity method based on linear least square inversion method. Among them, the frequency domain resistivity of the IP effect parameter design for parameters of polarimetric Seigel polarization theory to optimize the inversion, which is an innovative point of this article. To a few theoretical models, data calculation, this paper make up the lack of awareness rate of topographic effects on the frequency domain resistivity method in actual exploration, compared to the conventional linear inversion method, to improve the simulation accuracy and calculation speed, research,also for complex resistivity exploration rate method theory of the actual data processing and interpretation offers of help.Through studis on contents of this thesis, its significance lies in, not only can make up for lack of geophysical exploration, science and technology workers on complex resistivity topographic effects on understanding, but also provide theoretical and technical support necessary to promote the rate of China’s complex resistivity exploration level. |
PDF Full Text Request