The measurement and analysis of complex resistivity and induced polarization of shale cores

2016 ◽  
Author(s):  
Juan Chen ◽  
Tao Huang ◽  
Gang Yu ◽  
Zhanxiang He ◽  
Xuben Wang ◽  
...  
Keyword(s):  
Induced Polarization ◽  
Complex Resistivity ◽  
Measurement And Analysis

On: “Recent Advances and Applications in Complex Resistivity Measurements,” by K. L. Zonge and J. C. Wynn (GEOPHYSICS, Oct. 1975, p. 851–864)

Geophysics ◽  
1977 ◽  
Vol 42 (1) ◽  
pp. 120-121 ◽  
Author(s):  
P. H. Nelson ◽  
G. D. Van Voorhis
Keyword(s):  
Spectral Data ◽  
Induced Polarization ◽  
Complex Resistivity ◽  
Resistivity Measurements ◽  
Recent Advances ◽  
Measuring Techniques

In presenting a variety of induced polarization spectral data, Zonge and Wynn refer to a paper published earlier by us (Van Voorhis et al., 1973) which deals with the same topic. We feel Zonge and Wynn have misrepresented our measuring techniques, data, and conclusions in their references to our paper. Our principal objections center on three statements by the authors.

A hybrid correlation denoising method based on complex resistivity and application on spread spectrum induced polarization data

Geophysics ◽  
2021 ◽  
pp. 1-35
Author(s):  
Siming He ◽  
Jian Guan ◽  
Yi Wang ◽  
Xiu Ji ◽  
Hui Wang
Keyword(s):  
Hybrid Method ◽  
Spread Spectrum ◽  
Field Experiments ◽  
Noise Suppression ◽  
Random Noise ◽  
Induced Polarization ◽  
Data Simulation ◽  
Denoising Method ◽  
Complex Resistivity ◽  
Geophysical Surveys

In electrical exploration techniques, an effective suppression method for Gaussian and impulsive random noise in spread spectrum induced polarization (SSIP) continues to be challenging for conventional denoising methods. Remnant noise influences the complex resistivity spectrum and damages the subsequent interpretation of geophysical surveys. We present a hybrid method based on a correlation function and complex resistivity, which introduces the correlation analyses between the transmitting source, the measured potential, and the injected current signal. According to the analyses, reliable results for complex resistivity spectra can be calculated, which can be further used for noise suppression. We apply the hybrid method to both numerical and field experiments to process measured SSIP data. Simulation tests show that the hybrid method not only suppresses the two types of noise but also improves the relative error of the complex resistivity spectrum. Field data processing shows that the hybrid method can minimize the standard deviation of the data and possess a greater ability to distinguish adjacent objects, which can improve the reliability of the data in subsequent processing and interpretation.

RECENT ADVANCES AND APPLICATIONS IN COMPLEX RESISTIVITY MEASUREMENTS

Geophysics ◽  
1975 ◽  
Vol 40 (5) ◽  
pp. 851-864 ◽  
Author(s):  
Kenneth L. Zonge ◽  
Jeffrey C. Wynn
Keyword(s):  
Host Rock ◽  
Electromagnetic Coupling ◽  
Field Measurements ◽  
Complete Removal ◽  
Induced Polarization ◽  
Laboratory Measurements ◽  
Spectral Measurements ◽  
Complex Resistivity ◽  
Geophysical Interpretation ◽  
Rock Alteration

Several years of accumulating complex resistivity spectral measurements have indicated that there are still many unexplored areas in induced polarization surveying that need to be investigated for a more complete understanding of the polarization process. In addition to providing mineral discrimination capabilities, complex resistivity spectra can be used to differentiate between various barren host rock responses, to facilitate the complete removal of electromagnetic coupling, and to identify pipeline, fence, and various other cultural coupling effects. Results of field measurements are presented in an effort to demonstrate the utility of and necessity for making complete spectral measurements for serious geophysical interpretation. Correlation of field measurements with laboratory measurements on core samples from the same area demonstrates that strong electromagnetic coupling can be accurately removed from complete spectra without removing the important rock response. Recent field and laboratory measurements indicate that most, if not all, induced polarization responses attributed to magnetite are not really due to this mineral but can be traced to a host rock alteration response. Also, characteristic host rock signatures for sulfide environments appear to vary according to locality and type of deposits making it impossible to provide a universal set of signatures for sulfide deposits.

Spectral induced polarization parameters as determined through time‐domain measurements

Geophysics ◽  
1984 ◽  
Vol 49 (11) ◽  
pp. 1993-2003 ◽  
Author(s):  
Ian M. Johnson
Keyword(s):  
Frequency Domain ◽  
Time Domain ◽  
Field Trials ◽  
Induced Polarization ◽  
Polarization Data ◽  
Forward Solution ◽  
Spectral Parameters ◽  
Impedance Model ◽  
Measurement And Analysis ◽  
The Time Domain

A method for the extraction of Cole-Cole spectral parameters from time‐domain induced polarization data is demonstrated. The instrumentation required to effect the measurement and analysis is described. The Cole-Cole impedance model is shown to work equally well in the time domain as in the frequency domain. Field trials show the time‐domain method to generate spectral parameters consistent with those generated by frequency‐domain surveys. This is shown to be possible without significant alteration to field procedures. Cole-Cole time constants of up to 100 s are shown to be resolvable given a transmitted current of a 2 s pulse‐time. The process proves to have added usefulness as the Cole-Cole forward solution proves an excellent basis for quantifying noise in the measured decay.

Correlation analysis for spread-spectrum induced-polarization signal processing in electromagnetically noisy environments

Geophysics ◽  
2017 ◽  
Vol 82 (5) ◽  
pp. E243-E256 ◽  
Author(s):  
Weiqiang Liu ◽  
Rujun Chen ◽  
Hongzhu Cai ◽  
Weibin Luo ◽  
André Revil
Keyword(s):  
Signal Processing ◽  
Correlation Analysis ◽  
Correlation Coefficient ◽  
Spread Spectrum ◽  
Threshold Value ◽  
Induced Polarization ◽  
Gansu Province ◽  
Data Set ◽  
Complex Resistivity ◽  
Primary Current

In induced-polarization (IP) surveys, the raw data are usually distorted significantly by the presence of electromagnetic (EM) interferences, including cultural noise. Several methods have been proposed to improve the signal-to-noise ratio of these data. However, signal processing in an electromagnetically noisy environment is still a challenging problem. We have determined a new and simple technique based on the analysis of the correlation between the measured potential and the injected primary current signals. This processing is applied to the data acquired using a new frequency-domain IP method called the spread-spectrum induced-polarization (SSIP) approach. In this approach, we use a pseudorandom m-sequence (also called the maximum length sequence) for the injected primary current. One of the advantages of this sequence is to be essentially spectrally flat in a given frequency range. Therefore, complex resistivity can be determined simultaneously at various frequencies. A new SSIP data set is acquired in the vicinity of Baiyin mine, Gansu Province, China. The correlation between potential difference and transmitting current signals for each period can be used to assess data quality. Only when the correlation coefficient between the two signals is greater than 0.5 can the SSIP data be used for subsequent processing and tomography. We determine what threshold value should be used for the correlation coefficient to extract high-quality apparent complex resistivity data and eliminate EM-contaminated data. We then compare the pseudosections with and without using the correlation analysis. When the correlation analysis is used, the noisy data are filtered out, and the target anomaly obtained through tomography is clearly enhanced. The inversion results of the apparent complex resistivity (amplitude and phase) for the survey area are consistent with some independent geologic and drilling information regarding the position of the ore body demonstrating the effectiveness of the approach.

Synthetic and field-based electrical imaging of a zerovalent iron barrier: Implications for monitoring long-term barrier performance

Geophysics ◽  
2006 ◽  
Vol 71 (5) ◽  
pp. B129-B137 ◽  
Author(s):  
Lee Slater ◽  
Andrew Binley
Keyword(s):  
Electrical Properties ◽  
Internal Structure ◽  
Induced Polarization ◽  
Permeable Reactive Barrier ◽  
Zerovalent Iron ◽  
Polarization Data ◽  
Complex Resistivity ◽  
Electrical Imaging ◽  
Over Time

We performed a study of electrical imaging sensitivity to geochemical alteration of a zerovalent iron permeable reactive barrier (PRB) over time. Complex-resistivity measurements of laboratory cores from an operational PRB defined the electrical properties of both unreacted and geochemically altered (reacted) iron, as well as the growth rate of the reacted front on the up gradient edge of the barrier. Laboratory results were used to generate models of the electrical structure of the PRB at 0, 15, and 30 years of operation. Synthetic cross-borehole resistivity and induced-polarization data were generated and perturbed with errors representative of noise at the site. To generate reliable images of the engineered structure, a complex-resistivity inversion was employed with a disconnect in the regularization between the part of the finite-element mesh (FEM) representing the internal structure of the barrier and the remainder of the FEM mesh.Synthetic results show that although the internal structure of inverted images at 15 and 30 years does not accurately reflect the width of the reacted front, modeled along the up-gradient edge of the barrier, perturbations to the internal structure of the imaged PRB are diagnostic of the growth of the reacted front. Cross-borehole electrical data, obtained at the field site during a 15-month period, demonstrate that the complex-resistivity algorithm can resolve reliably the PRB target using the engineering design specifications to define the correct shape of the regularization disconnect. Both resistivity and induced-polarization reciprocal errors are low, and the induced-polarization data are highly repeatable over this period. Changes in the electrical properties of the PRB over time were small but consistent with growth of a reacted front, based on the synthetic study. Significantly, resistivity imaging alone may be sufficient for long-term monitoring of precipitation, leading to reduced PRB performance.

EM COUPLING, ITS INTRINSIC VALUE, ITS REMOVAL AND THE CULTURAL COUPLING PROBLEM

Geophysics ◽  
1975 ◽  
Vol 40 (5) ◽  
pp. 831-850 ◽  
Author(s):  
Jeffrey C. Wynn ◽  
Kenneth L. Zonge
Keyword(s):  
Electromagnetic Induction ◽  
Electromagnetic Coupling ◽  
Intrinsic Value ◽  
Low Frequency ◽  
Induced Polarization ◽  
Electrode Polarization ◽  
Electrically Conductive ◽  
Coupling Problem ◽  
Complex Resistivity ◽  
Deep Sounding

The induced polarization method of geophysical prospecting has been in use for more than 25 years with varying degrees of success. Until recently, its two principle drawbacks were (1) the inability to distinguish between anomalous rock responses and, (2) inability to distinguish between these rock responses and inductive coupling. The first problem was solved by K. L. Zonge in 1972. Solutions to the coupling problem go back to 1932, and have been expanded and elaborated upon by successive authors since then. In most of these papers, electromagnetic coupling was separated into two functions, here designated as P, a purely inductive term, and Q, a grounding or purely resistive term. This paper extends this work into a study of the reflective coupling contribution and the effects of anisotropy. Two immediate results are: (a) the development of an ultra‐low‐frequency deep sounding technique for highly conductive overburden environments, and (b) a successful iterative technique for the removal of coupling from complex resistivity field data. A study was made of the effect of electrically conductive pipelines on induced polarization and complex resistivity data. It appears that the so‐called “pipeline effect” is a composite of several effects, including current focusing nonlinearities, electromagnetic induction, and complex electrode polarization. The pipeline effect is generally predictable, while the effect of a fence or an irregular conductive inhomogeneity is not as simple.

scholarly journals 3D induced-polarization data inversion for complex resistivity

Geophysics ◽  
2011 ◽  
Vol 76 (3) ◽  
pp. F157-F171 ◽  
Author(s):  
Michael Commer ◽  
Gregory A. Newman ◽  
Kenneth H. Williams ◽  
Susan S. Hubbard
Keyword(s):  
Environmental Remediation ◽  
Large Scale ◽  
Forward Modeling ◽  
Induced Polarization ◽  
Inversion Method ◽  
Data Sets ◽  
Inversion Algorithm ◽  
Data Set ◽  
Complex Resistivity ◽  
Data Inversion

The conductive and capacitive material properties of the subsurface can be quantified through the frequency-dependent complex resistivity. However, the routine three-dimensional (3D) interpretation of voluminous induced polarization (IP) data sets still poses a challenge due to large computational demands and solution nonuniqueness. We have developed a flexible methodology for 3D (spectral) IP data inversion. Our inversion algorithm is adapted from a frequency-domain electromagnetic (EM) inversion method primarily developed for large-scale hydrocarbon and geothermal energy exploration purposes. The method has proven to be efficient by implementing the nonlinear conjugate gradient method with hierarchical parallelism and by using an optimal finite-difference forward modeling mesh design scheme. The method allows for a large range of survey scales, providing a tool for both exploration and environmental applications. We experimented with an image focusing technique to improve the poor depth resolution of surface data sets with small survey spreads. The algorithm’s underlying forward modeling operator properly accounts for EM coupling effects; thus, traditionally used EM coupling correction procedures are not needed. The methodology was applied to both synthetic and field data. We tested the benefit of directly inverting EM coupling contaminated data using a synthetic large-scale exploration data set. Afterward, we further tested the monitoring capability of our method by inverting time-lapse data from an environmental remediation experiment near Rifle, Colorado. Similar trends observed in both our solution and another 2D inversion were in accordance with previous findings about the IP effects due to subsurface microbial activity.

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