The Study Of Simulation And Inversion Of 1D Spectrum Induced Polarization Method

Induced polarization method based on the differences of the geologic body's induced polarization characteristics, and the characteristics show different in DC field and AC field. Therefor, IP method divide into DC method and AC method, AC method classified as variable frequency method and Sip method. Up to 1941, K.S.Cole and R.H.Cole expressed the complex resistivity by a mathematical models, named Cole-Cole model. After that, Pelton proposed a new kind of IP method (SIP method) which uses Cole-Cole model to describe the induced polarization characteristics at 1978. SIP is a new developing IP method which based on the differences of the geologic body's frequency spectrum characteristics, and according to the geologic body's frequency spectrum parameters to evaluate the electric branch of abnormal geologic body. Because of its deep exploration to the metallic mineral, observation of multi-parameter, according toτand c to distinguish between mine and non-mine, so SIP has the outstanding advantages to the regular IP method. It has been proved that the electrical anomaly of geologic body can be quantitative estimated by Cole-Cole model parameters. It is very important to study the methods to obtain the complex parameters of geologic body.This article introduced the development of the SIP method, Cole-Cole model and some other equivalent model, carry out the description and analysis of Cole-Cole model spectrum parameters and spectrum characteristics.In the first place, this article make a in-depth analysis on SIP's research and development process, and find most of them ignored the effect of electromagnetic coupling. After that, I describe Cole-Cole and some other equivalent model, because of the fine simplicity and accuracy, cole-cole model was chosen for the farther research. Simply analyze the Cole-Cole model spectrum parameters and complex resistivity real component and imaginary component, phase, amplitude, by selecting different spectrum parameters to draw normalized graph at the frequency 10 ? 2 ~ 10 4Hz.By only considering the role of conduction current, forward modeling selects the 1D layered media. Choose the linear filtering algorithm to calculate Hankel transform, because of the adventages of speed and accuracy. Field observational data by the method of SIP always includes electromagnetic coupling of varying degrees. Therefore, this article implements forward modeling respectively with only IP effect response and with IP effect and the coexistence of two kinds of electromagnetic coupling, in order to contrast electromagnetic coupling effect with the response of IP. For the same reason, schlumberger configuration and dipole-dipole configuration are chosen to compare, and selecte 2 and 3 layered medium to calculate with two different electrode distance. Finaly, analyze the parameters' effects to the forward modeling response.As the inversion of the spectrum of IP inversion, whether conventional or realistic parameter inversion, generally carried out by damped least square inversion. Therefore, this article also use the damped least squares method in the inversion. In the case of neglecting the electromagnetic coupling effect, only considering the case of IP effect, work out 2 and 3 layered medium to inverse with cole-cole model. Inversion parameters are m,τ,c ,and the layer depth h .Based on the research on simulation and inversion of SIP method, we wish it could be some references and theoretical basis of experimental simulation, instrument design, practical application.