Three-dimension Cole-Cole model inversion of induced polarization data based on regulated conjugate gradient method

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Title Three-dimension Cole-Cole model inversion of induced polarization data based on regulated conjugate gradient method
Publication Type dissertation
School or College College of Mines & Earth Sciences
Department Geology & Geophysics
Author Xu, Zhengwei
Date 2013-05
Description Modeling of induced polarization (IP) phenomena is important for developing effective methods for remote sensing of subsurface geology and is widely used in mineral exploration. However, the quantitative interpretation of IP data in a complex 3D environment is still a challenging problem of applied geophysics. In this dissertation I use the regularized conjugate gradient method to determine the 3D distribution of the four parameters of the Cole-Cole model based on surface induced polarization (IP) data. This method takes into account the nonlinear nature of both electromagnetic induction (EMI) and IP phenomena. The solution of the 3D IP inverse problem is based on the regularized smooth inversion only. The method was tested on synthetic models with DC conductivity, intrinsic chargeability, time constant, and relaxation parameters, and it was also applied to the practical 3D IP survey data. I demonstrate that the four parameters of the Cole-Cole model, DC electrical resistivity, p0 (or electrical conductivity <r0 = 1 / p 0 ), chargeability, r ; time constant, r ; and the relaxation parameter, , can be recovered from the observed IP data simultaneously. There are four Cole-Cole parameters involved in the inversion, in other words, within each cell, there are DC conductivity ( ), chargeability ( ), time parameters ( ), and relaxation parameters ( ) compared to conductivity only, used in EM only inversion. In addition to more inversion parameters used in IP survey, dipole-dipole configuration which requires more sources and receivers. One the other hand, calculating Green tensor and Frechet matrix time consuming and storing them requires a lot of memory. So, I develop parallel computation using MATLAB parallel tool to speed up the calculation.
Type Text
Publisher University of Utah
Subject Induced polarization; Parallel computing; Porphyry Copper Deposits; Regularized conjugate gradient method; sensitivity; Three-dimension Cole-Cole model inversion
Dissertation Institution University of Utah
Dissertation Name Doctor of Philosophy
Language eng
Rights Management Copyright © Zhengwei Xu 2013
Format application/pdf
Format Medium application/pdf
Format Extent 2,887,227 bytes
ARK ark:/87278/s6t72z9r
Setname ir_etd
ID 195945
Reference URL https://collections.lib.utah.edu/ark:/87278/s6t72z9r
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