In frequency-domain sounding, "false extreme" phenomenon often appears in the apparent resistivity curve. Previous investigations focused on the subject without considering strata information containing in false Extreme. The use of false extreme effect is a new attempt to explain data. This paper analyzes...

Three-dimensional (3D) inversion of full tensor gradiometry (FTG) data continues to be an active area of research and development. We have recently developed a method of potential field migration, which extends to the case of the potential field the general principles of seismic and electromagnetic migration....

In this study, we presented a new multi transient electromagnetic (MTEM) data acquisition array to solve the challenges observed in using the conventional data acquisition setup in MTEM survey over complex geology. This involves the use of double transmitter dipoles and the recording of both the forward...

The Surface Electromagnetic Prospecting system developed by Institute of Geology and Geophysics, Chinese Academy of Sciences was introduced through a CSAMT case study in Dongguashan copper mine in east of Tonglin, Anhui province. Strong electromagnetic noise generated by mineral industries and nearby...

Pseudo-Random binary sequence source is introduced to artificial electromagnetic method, it is necessary to use special technique to process the signal in time domain. In order to test the quality of data processing technology, it is indispensable to compose electromagnetic signal of simulated model...

The integration of geochemical and geophysical methods was applied to epithermal gold-quartz veins exploration in Chukotka tundra (North-East Russia). The feature of the investigated area is that the gold-quartz veins are blind and are located 50-120 m below the surface under the layers of low-resistive...

In antenna theory, the dipole hypothesis is applicable and widely used for observing the far-field radiation. However, when applied to near-field quasi-static radiation observation in geophysical surveying, the transceiver distance is often small, and thereby the source should not be treated as a dipole...

Qiangtang basin is the largest oil and gas basins of the Tibet plateau, the permafrost distributed widely, having good formed condition and prospecting of gas hydrate. There is carried out audio magnetotelluric (AMT) exploration research in YaHu area in order to find out the basic accumulation conditions...

CSAMT always use MT to calculate the Cagniard resistivity which is the ratio of electric field component and magnetic field component. CSAMT field source is known and the electric field component and the magnetic field component have a certain relationship with the underground resistivity. Therefore...

In seismic exploration, seismic data is always irregular and incomplete which will influence the subsequent processing. Therefore, seismic reconstruction of missing traces is very necessary. The seismic data reconstruction method based on compressive sensing (CS) has been applied widely in recent years....

Seabed EM surveys in shallow water environments have a number of specific particularities. Specifically, there is difficulty with hermetical sealing of EM instruments and the necessity of overcoming electromagnetic noise caused by underwater currents and sea surface disturbances. Another problem is the...

Underground magnetic resonance sounding (MRS) low signal-noise ratio (SNR) weak signal is hard to manage with traditional de-noising method such as fitting and filter. In view of this, this article makes use of both transient electromagnetic method (TEM) data and MRS data obtained from integrated detecting...

It is generally accepted that a major phase of the Earth's upper mantle is represented by ultramafic rocks, including olivine pyroxenites, dunites, and peridotites. Studies on the electrical conductivity of ultramafic rocks continue to attract a great deal of interest, and much progress in the study...

In northwest China, the widespread Laterite of Neogene Pliocene series (N2) is the direct aquifuge above Jurassic coal seam, which plays a vital role in the protection of shallow water resources. With the rapid growth of coal production in this area, the N2 Laterite was severely damaged by the extensive...

Jiaodong area is the most important gold concentration area in China with huge prospecting potential in deep portion. Magnetotelluric(MT) has some advantages of great exploration depth, high resolution and low cost, so we arrange MT exploration in Jiaodong area with less previous work for the deep structure...

The water-riched overburden of a seabed mine poses threat to safe exploitation. The level -135 m strike drift of the Xinli mine district of Sanshandao gold mine in Shandong province was selected to be the survey site for electrical imaging, in order to map the groundwater distribution of the overlying...

In this paper, we proposed a novel TEM device-borehole SOTEM based on the advantages of borehole TEM and ground SOTEM. In order to get a preliminary understandingÿto this method, we calculated the response on two-dimensional earth using FDTD scheme and analyzed its characteristics as well. The results...

In this paper, the direct time domain vector finite element method was used to forward three-dimensional transient electromagnetic fields excited by loop source. From Maxwell's equations met by time domain electromagnetic field we can directly export the double curl equations met by electric field, and...

Marine electromagnetic transmitter is one of the key devices for marine electromagnetic exploration, the large current transmitted by the device as well as the data collected by the receiver would undergo process and invert calculation to master the shallow resistivity structure under the seabed. The...

It is very important to get a reliable result in transient electromagnetic (TEM) inversion. Most of the traditional inversion algorithms are based on the assumption that resistivity changes smoothly underground, through which we cannot get clear geological interface. With the purpose to represent clear...

The encoded source electromagnetic sounding method based on circular correlation identification and the calculation method of whole zone apparent resistivity are put forward. Using the inverse repeated M sequence as the excitation signal, the encoded current from the source is through the grounded electrodes...

In the exploitation of the mineral resources, deep subsurface structure research can explain the formation mechanism of resources and guide proper resource assessment. Receiver-function is an effective method to solve problems related to deep structure. Based on the uncertainty of this method, which...

The influence of ionosphere and displacement current can not be ignored in earth-ionosphere mode.This leads to a highly oscillating kernel function and it's hard to get accurate results using traditional fast Hankel transform(FHT) method.This paper attempts to solve this problem using quadrature with...

Soil parameters have important impacts on the response to earthquake damage. Refraction microtremor (REMI) method is of practical Refraction microtremor method uses the conventional seismic recording instruments during the progress of seismic data acquisition. It takes about 40s in one acquisition, which...

Transient electromagnetic method has gradually became a popular geophysical prospecting method in recent years in China and rest of the world. Considering the complexity of the transient electromagnetic theory, the theory of technology is still imperfect, especially in the area of 3D inversion processing...

In order to improve the comprehensive prospecting effect, wide field electromagnetic instrument system is used in Liaoning Benxi ore concentration area for large depth and high precision geological mapping experimental work, 2D inversion imaging work is conducted based on nonlinear conjugate gradient...

Considering the charateristics of marine gas hydrate containing area such as faulted structures are developed and reservoir distribution is not clear, this paper uses the recursive inversion method based on deconvolution to carry out the poststack constrained sparse spike inversion without well data...

The previous person thought that the M163-1 aeromagnetic anomaly is caused by the concealed and magnetite content alteration gabbro, but through the study of regional gravity, magnetic data and geological data,we thought M163-1 aeromagnetic anomaly has the larger mineralization potential., which compare...

Traditionally " "Bz/" "T is used to obtain the apparent resistivity values in the data interpretation of grounded-wire source transient electromagnetic, which leads to the problem of multiple solutions. Using Bz, this problem can be solved. Because with the change of resistivity, the Bz is a single-valued...

Water channel detection has become the focus and difficulty of tunnel detection because of needing a higher resolution. We put forward the array antenna source transient electromagnetic tunnel detection method on the basis of radar array antenna. Firstly, it verifies that the array antenna source has...

The middle-east region of Qinshui coalfield locates in the eastern of Qinshui block depression, which terrain ups and downs and the surface lithology is changeful. How to choice the excitation and receiving parameters becomes the main difficulty. In this paper, the methods of micro logging and refraction...

In GPR imaging, it is common for the depth of investigation to be on the same order as the variability in surface topography. In such cases, migration fails when it is carried out from a datum after application of elevation statics. We introduce a reverse-time migration algorithm where the wavefield...

Surface wave analysis performed on data acquired on purpose or extracted from seismic gathers acquired for body wave surveying is a powerful tool for S-wave velocity model estimation. S-wave velocity is relevant for many engineering applications, but the recent application for hydrocarbon exploration...

Resistivity method is generally considered suitable for investigation of seepage problems in earthen embankments. Construction of a large embankment dam in Taiwan was recently completed, providing a good opportunity for ERT monitoring of the entire water filling process and future performance. The proposed...

Near source time-domain electromagnetic field has the advantages of strong signal, great detection depth, and high accuracy, but according to the traditional transient electromagnetic field theory, the dipole approximation in near source zone will cause a bigger error. To carry out direct time-domain...

In order to grasp the rule of mining transient electromagnetic multi-components characters, numerical modeling methods are employed to simulate the advanced prospecting multi-components response characteristics of gob water with measuring-point arrangement of fanned shape. Results of numerical modeling...

This article is about the study of time domain electromagnetic data migration imaging. First, based on the electromagnetic diffusion theory and the boundary conditions, we deduce the analytical formula of electromagnetic migration field. Then, we complete the calculation of electromagnetic migration...

This article studies the formation, propagation and spatial distribution of the two types of channel wave in three-dimensional space, using three-dimensional inhomogeneous isotropic medium wave equation and solving the elastic wave equation with finite-difference method. Geological model designed in...

The bipolar synchronous sampling method is widely used for noise reduction in Transient Electromagnetic Measurement. However, in practice the ability of this method is not enough to reduce the strong noise from multi-sources. In this paper, we propose an improved method for optimization of the Instrument...

Commonly, TEM data is plotted as apparent resistivity versus time. Later on, with improvement in computer technology, inversion programs have got attention of EM geophysical community. Recently, inversion routines are applied to 1-D problems. In this paper we propose a new approach to interpret SOTEM...

Coal seam seismic survey collapse column is common in heterogeneous geologic bodies. Groud-3D seismic observation due to limitations of its accuracy, for uneven geological subsided column often small leakage test or position error is large, the impact of mining coal mine safety sometimes causing heavy...

Grounded electric source Borehole TEM is introduced in this paper to find the deep conductive ore body, particularly in areas where the ability of surface TEM to define a target is limited either by large depths or by interfering conductive bodies such as overburden shallow sulphides and peripheral mineralized...

With the depth of Coal mining deepen, it becomes a greater challenge to prevent and control water. Quantitative predication on the water abundance of coal seam rapid has become a serious problem. However, since inherent limitations of the method, only qualitative judgments can be done. Based on the numerical...

The traditional optimization inversion method based on iterative method strongly depends on the selection of the initial model, which may easily leads to the local optimal solution, however, the smoke ring inversion has the advantages of fast calculation and no need of initial model. Therefore,the results...

Ray intercept algorithm is the key factor to improve the speed of radio tomography. A second scan search algorithm is proposed to acquire the intersecting point coordinates between ray and gridlines. For this algorithm , successive scanning and sorting of intersection sequence would consume much computing...

The circular loop source is calculated by the method of inscribed polygon inner the circle or numerical calculation. The former uses decomposed polygon in each side with electric dipole, then stack all the electric dipole response; the latter adopts the method of digital filter to calculate the integral...

The lag of water inrush from goaf floor is a great threat to the safety in production, which often leads to a serious property loss. A three-dimensional DC resistivity method,based on the mechanism and the inducing factors of water inrush,is proposed to monitor the possible water inrush accident in this...

Scattering wave imaging method and technique is a new kind of prestack migration. Based on the assumption that the earth subsurface consists of a large number of points (referred to as scatter points), closely located on the interfaces, scattered-waves is formed by single point scattered-wave. Other...

The data acquisition mode of Multi-channel transient electromagnetic method (MTEM) is similar to that of seismic method, it is significant to research pseudo-seismic wave-field extraction technology for MTEM data. Basing on singular value decomposition method and regularized method, we propose correlation...

In normal TEM sounding, the parameter of secondary induced voltage V signal is collected by using magnetic induced coil, however, the late signal is usually too weak to distinguish deep buried target. In this paper, direct measuring of B-field parameters is used to test its practical effect. Firstly,...

A new mine transient electromagnetic method based on U-shape spiral source is proposed. Firstly, the method is introduced. The character of new system is based on a U-shape spiral source which is made up of a U-shape support and the spiral power wire. Furthermore, we analyze the potential advantages...

For the real-time, on-site, direct monitoring of coalfield fire area temperature, we developed a permanent WSN monitoring system with the functions of continuous collection, high temperature detection, remote control, etc. By designing the software and hardware of SPI interface between the JN5139 chip...

The low-resistivity covered layer has shielding effects on transient electromagnetic (TEM) field above prospecting target. The probing depth of TEM depends on observation time. So, it is of great guiding significance to study the estimation method of observation time with low-resistivity covered layer....

Zoeppritz equations can only describe the reflection and transmission of plane waves incident on a single interface. It cannot deal with the thin bed case. The presence of dirt band in thin coalbed makes the problem even more complicated. We present an AVO (amplitude variation with offset) analysis of...

The paper deduced the electrical penetration potential equation of measuring point in point-source current field from the case study of conductive sphere, and proposed the question of the relationship between the response characteristics of electrical penetration curve and spatial location of anomalous...

Acoustic wave equation is an important basis of seismic wave propagation,imaging and migration. Finite difference methods develop with its numerical stability and grid dispersion problems, and the issue of dispersion is a vital above all. Optimization methods can provide a high accuracy within a large...

The coal bed methane (CBM) content is often relatively high where the immediate roof and floor of the coal seam are mudstone. In order to predict the CBM rich region, position of coal seam roof and floor and distribution of sandstone and mudstone are based on acoustic wave impedance inversion and pseudo-acoustic...

we demonstrate how several tools, such as stacking, cross correlation, digital filtering, significantly attenuate the correlated and uncorrelated noise encountered during the estimation of the earth impulse response of multi-transient electromagnetic survey. This study focuses on processing of correlated...

The denoising process is critical when processing transient electromagnetic (TEM) sounding data. For the full waveform PRBS response, an inadequate noise estimation may result in an erroneous interpretation. We consider the Hilbert-huang transform and its application to suppress the noise in the PRBS...

Full waveform inversion (FWI) is an effective inversion method to obtain high resolution and precision seismic imaging. There are a lot of conventional local optimization methods, such as Newton's method and gradient method, to solve the ill-posed nonlinear problem. However, these methods always lead...

In coal exploration, seismic strong reflections from overlying strata may shield the propagation of seismic waves into deep parts, resulting in poor imaging quality for deep targeted area. In fact, seismic wave energy will be lost and velocities will undergo dispersion after passing through viscoelastic...

In order to improve the accuracy of mine transient electromagnetic(MTEM) detection results we carried out field detection experiments for the underground metal interference (tunneling machine, bolt and the anchor net),by analyzing the effects of interference, it turns out that these metallic facilities...

Because the buried hill is deeply buried and seismic data is difficult to identify, it is difficult to exploration the buried hill in Jizhong Depression. Time-frequency electromagnetic method(TFEM)has the characteristics with directly detecting oil and gas reservoirs, and core drilling test and analysis...

The total organic carbon content (TOC) is an important parameter for source rocks evaluation in coal measures. Total organic carbon content determined from logging parameters using back propagation neural network technique, which provide a new method for hydrocarbon source rock evaluation. Use the Turpan...

Taking advantage of the research results of the transmission wave field response in in-seam seismic survey(ISS), and according to the related laws between the L-wave dispersion characteristics and the seam thickness, the technology based on the transmission method of ISS has been developed for quantitative...

Geoelectric investigation, involving electrical resistivity method, was carried out within a site earmarked for an airport runway in the Mambilla Plateau, Taraba State, Nigeria. The objective was to generate surface and subsurface geologic information required for the location and design of a stable...

The frequency domain electromagnetic methods (FDEM) could be separated in two groups: 1)Shallow FDEM profiling techniques which use high frequency bands and mainly utilize only the magnetic components of the EM field; 2)Electromagnetic soundings in wide depths intervals, consisting of two sub methods:...

By using the borehole elastic modulus test and sound wave inspection for typical representative spots of a dam foundation, the deformation behavior parameters of grouted weak rock of workplace foundation are obtained, and the potential relationship between wave velocity VP and elastic modulus E is derived....

We demonstrate that common mid-point (CMP) stacking analysis for common virtual-source (CVS) cross-correlation gathers of multi-channel and single-shot surface wave data give accurate phase-velocity curves, and enable us to reconstruct 2D Vs structures with high resolution. Data processing for CMP stacking...

Rayleigh waves have been widely used to estimate the shear-wave velocity structure in the fields of shallow engineering and environmental detection. In this study, active and passive surface wave surveys were performed sequentially on the same survey line across the eastern Balikun Basin. MASW (Multi-channel...

Surface microseismic monitoring of hydraulic fracturing is now becoming more and more popular in the production of unconventional hydrocarbons. The frequency analysis of surface detected microseismic event and comparison with perforation event and downhole recorded event may lead to deeper understanding...

to interpret small faults is always the core question for seismic exploration. Seismic attributes can help us understand the fault and fracture system better. The earthquake frequency controls seismic resolution, if the resolution is relatively low, minor faults or micro-fractures portrayed through the...

Time-domain multi-scale full waveform inversion (FWI) is an important method for seismic imaging. Using different frequency contents of seismic data, this method mitigates the effect of the local-minima problem by sequential inversion. One of the important factors determining the convergence rate of...

In cold regions, heaving of the railway subgrade is an important security risk to high-speed railway. It is necessary to find out the moisture content of the subgrade to secure the normal railway operation. Common Mid-Point (CMP) measurement using Ground Penetrating Radar (GPR) was carried out to estimate...

Surface based micro-seismic monitoring of well stimulation by hydraulic fracture now has been accepted by domestic oil and gas industry. Micro-seismic data can be used to evaluate the stimulation result, predict reservoir stress state and guide the drilling of horizontal laterals, etc. Surface based...

The passive surface wave method can detect the shear wave velocity structure of subsurface mediums, by recording the vertical component of weak vibration on the earth's surface, and then extracting Rayleigh wave dispersion curve. This paper documents the first application of the passive surface wave...

With the development of the seismic numerical modeling theory, a group of scholars do lots of seismic forward modeling studies. In this paper, wave equation finite difference method(FDM)[1] was used to build models of submarine fault and slide and forward seismic modeling. By studying character and imaging...

There are rich cultural heritages both underwater and in land in China, which is the object concerned by archaeologists and historic researchers, especially the ancient wooden sunken boats containing the past information of old human civlilization we can restore. Detections for buried magnetic massive...

In order to explain the surveyed data more accurately and have a better understanding of the distribution of geoelectricity, two-dimensional partial differential equations of Magnetotelluric in anisotropic media are employed to establish vertical layered medium axially anisotropic model by Fourier Transform...

We present in this paper a forward modelling of the three dimensional off-resonance response of underground MRS used in advanced geological prediction of constructing tunnel. By considering and summarizing the off-resonance response in SNMR, we deduced the off-resonance response of underground MRS. Using...

The Gonghe basin in north-eastern Qinghai-Tibetan plateau of China is a potential geothermal field, where there have been some hot springs discovered in recent years. The seismic and magnetotelluric sounding (MT) inversion results in this area show that there are deep crustal fractures which might be...

Because of the strong energy of Rayleigh wave, high signal to noise ratio and high efficiency, as a new type of engineering geophysical exploration methods, Rayleigh wave exploration get more and more attention in recent years.And because of the in-homogeneity of the earth's surface medium, the Rayleigh...

We present a combined early arrival P-wave and Rayleigh wave inversion strategy that uses the cross-gradient between the P-velocity and S-velocity as a regularization term. First, the P-velocity model is inverted by the early arrival full wave inversion (FWI) method. Then the magnitude spectra of the...

How to overcome the urban interference, especially to suppress day and night traffic vibratory noise in underlying Xi'an ground fissure exploration has been a difficult problem for shallow seismic prospecting in engineering purpose. Based on in Xi'an Metro Line 6 engineering, we try to use large tonnage...

Since the 1950 s, Taolin ore has been exploited. Almost a hundred tons of tailing were backfilled between the hills for a long time, which formed Taolin dam during 50 years backfilling deposition. The stability of the huge dam is of great importance for the local people's life and property protection....

In view of the problem that widespread existing undulating terrain and anisotropic in the actual geophysical prospecting, we propose a numerical simulation method which only needs discrete nodes to construct the shape function. Assuming the electrical spindle axis of underground anisotropic medium is...

A novel technique for synthetic source of multiple electromagnetic data sets is presented. The technique applies weighting to multiple transmitters of small magnetic moment loops to form a synthetic source for deep deposits exploration in complex terrain. In order to determine the weighting coefficient,...

A 3D frequency-domain finite volume method (FVM) solver is developed for scattering from lossy objects embedded in layered media. Based on the Yee staggered grids, the formulation derivation for FVM are presented in this paper. Two numerical examples with a 3D cuboid embedded in a half space and in a...

A numerical approach for free surface boundary formulation is proposed for simulation of surface waves in porous media, based on the Biot poroelastic model. A set of free surface characteristic variables for incoming and outgoing wave fields are set by domain decomposition for solid and fluid velocity...

Hydrocarbon source rock is the foundation of oil and gas exploration research. At present, geochemical methods are still the mainly used for hydrocarbon source rock studies, which is hard to obtain a continuous data on a single well owing to the limited samples and experimental fees. Logging information...

In the stage of oilfield development, the fractures of clasolite reservoir begin to develop after the process of fracturing and water flooding. At the same time, the lateral heterogeneity has the significant changes, and this situation will cause the abnormal changes of many seismic attribute parameters....

to be differently using the amplitude section from stack volume, the acquisition footprint can be represented by energy distribution of the raw seismic in the paper. Furthermore, the paper discussed the distributions of the offset entropy and azimuth entropy of the geometry, described the similarity...

At present, the radar is used to analyze the radar time range profile, which is mainly based on the kinematic characteristics of radar wave. With the constantly mature of the analytic method of signal analysis of GPR, we can effectively extract the "three instantaneous attributes" (the instantaneous...

In the middle of the last century, surface multiturn coils and quartz variometers served as sensor components of the alternating magnetic field. Later, they were replaced by fluxgate sensors measuring the alternating magnetic field against its constant component and induction sensors reacting only to...

With the rapid advance of Chinese cities constructions, the lack of urban land is going increasingly. While in urban planning, people should avoid the hidden active faults, because they directly triggered a variety of geological disasters such as rupture, earthquakes. In order to solve this contradiction,...

In order to estimate the geological and structural rock mass characteristics in the site of upper course cofferdam of water inlet, gate shaft of water inlet and Sd1 district in south bank expansion project of Kariba south power station, Some experimental investigations were done based on the acoustic...

Detection of pile foundation is one of the most important procedures in the evaluation of pile bearing capacity and pile quality. In this paper, the application of the transient Rayleigh technology in detection of pile foundation (pile integrity, pile verticality and pile bearing capacity) have been...

Based on the generic name of Continuation Period Techniques (CPT), various different and effective Geophysical Techniques are covered. According to the Paragraph 69, Part II of the Protocol to the Comprehensive Nuclear-Test-ban Treaty(CTBT), the techniques allowed once the continuation of the inspection...

Funded by major national scientific research and equipment development project, the development of multi-channel transient electromagnetic system is led by the Institute of Geology and Geophysics, Chinese Academy of Sciences. It consists of pseudo random coded waveforms and high power transmitter with...

We examine laboratory data from creep tests performed on a thermally cracked water-saturated glass sample and estimate Young's modulus and extensional-mode attenuation as functions of frequency. An SEM image of a vertical cross-section through the upper half of the cylindrical sample has been digitized...