Finite Element Modeling Of 3-D Spectrum Induced Polarization Method

The Spectrum Induced Polarization method(SIP)is also known as the Complex Resistivity method(CR),which belongs to the Frequency domain IP method in the method of Induced Polarization The method is mainly based on the difference of conductivity(resistance)of rock ore and the difference of excitation intensities(excitations),and has more electrical parameters,which can provide more abundant information for the identification of anomalies.In recent decades,it is one of the most important methods in the exploration of shallow metals in China.In recent years,it has been applied to deep oil and gas exploration,and has achieved good results.It is important to study that characterization of abnormal bulk property in the spectrum excitation method.What's more,investigating how to judge the position,size and mineral types of the abnormal body in the actual production application,and understanding the underground abnormal situation,and is indispensable in the numerical simulation of the threedimensional numerical value.This paper introduced some equivalent models for the equivalent simulated rock ore complex resistivity in Spectrum Induced Polarization at first,and discussed the characteristics of each complex resistivity parameter reflected at different frequencies in the Cole-Cole equivalent model.Using the Cole-Cole model equivalent to represent the abnormal area of the complex resistivity of the various elements of the unit and using the Finite element method hexahedral unit for the 3-D area of the anatomy without considering the electromagnetic coupling,This paper can realize a continuous change of rock electrical properties ore spectrum IP finite element three-dimensional forward modeling by using the three linear interpolation between the unit to ensure the complex conductivity and continuous change of complex potential.Based on the results of previous studies,the effectiveness of the 3-D finite element forward program based on the theory of this paper was verified by using a two-layered layered model with polarization.And then we did a numerical different kinds of simulations,and then analyzed the response characteristics of the various electric parameters to the model of the laminar model and the virtual weight of the curve.As for complex geological conditions in the actual work mantle models,low-resistance polarizing block models,polarized standing plate models,low-resistance polarized horizontal plate models,and a plurality of different physical properties of polarization block models have been designed.Dipole-dipole devices commonly used in actual work are subjected to 3-D numerical simulation.The response characteristics of the real and imaginary components of each model are analyzed.The results show that: The situation has a good indication;the apparent component of the complex resistivity is more sensitive to the resistivity change of the anomaly body.If the anomalous body has an induced polarization property,the stronger the induced polarization is,it affects the real component of the apparent complex resistivity.The imaginary component of the complex resistivity is more sensitive to the induced polarization response of the anomalous body.If the polarization of the anomalous body and surrounding rock is significantly different,the resistivity of the two is closer and the imaginary component is the clearer the response to the difference.The results of the 3-D forward program of the finite element method based on the theory of this paper are accurate,and it has great applicability to the simulation of anomalous body,which can lay a foundation for the multi-parameter 3-D inversion of spectrum in the later stage.