Amplitude preprocessing of single and multicomponent seismic data

Geophysics ◽  
1992 ◽  
Vol 57 (9) ◽  
pp. 1178-1188 ◽  
Author(s):  
C. P. A. Wapenaar ◽  
D. J. Verschuur ◽  
P. Herrmann
Keyword(s):  
Point Source ◽  
Seismic Data ◽  
Line Source ◽  
Cylindrical Symmetry ◽  
Two Dimensions ◽  
Underlying Assumption ◽  
Seismic Processing ◽  
Acoustic Data ◽  
Elastic Data ◽  
Processing Techniques

Whenever the data acquisition is restricted to line surveys rather than areal surveys, seismic processing is necessarily in two dimensions. In this paper it is argued that two‐dimensional (2-D) processing is preferably applied after transforming the point source responses into line source responses. The effect of this transformation is a correction of the amplitudes in the data. For single‐component acoustic data as well as for multicomponent elastic data a line source response is nothing but a superposition of point source responses. Hence, in principle a line source response can be synthesized by integrating point source responses along the desired line source axis. In practice, however, this integration cannot be carried out due to the incompleteness of the data. It is shown that the integration along the source axis can be replaced by an integration along the receiver axis. The underlying assumption is that the wavefields exhibit a certain type of cylindrical symmetry. For horizontally layered acoustic and elastic media this assumption is fully satisfied. For 2-D inhomogeneous media this assumption is approximately satisfied, provided the data are sorted in CMP gathers. Having transformed the point source responses into line source responses, the results may be considered as “true amplitude” 2-D data. Hence, proceeding with existing 2-D seismic processing techniques is then justified.

Transformation from 2-D to 3-D wave propagation for horizontally layered media

Geophysics ◽  
1994 ◽  
Vol 59 (12) ◽  
pp. 1920-1926 ◽  
Author(s):  
Lasse Amundsen ◽  
Arne Reitan
Keyword(s):  
Wave Propagation ◽  
Point Source ◽  
Line Source ◽  
Layered Media ◽  
Cylindrical Symmetry ◽  
Seismic Processing ◽  
Geometric Spreading ◽  
Processing Algorithms ◽  
The Relationship ◽  
D Wave

The relationship between 2-D and 3-D wave propagation in horizontally layered media was first investigated by Dampney (1971). In the last few years the usefulness and feasibility of transforming point‐source responses with 3-D geometric spreading to equivalent line‐source responses with 2-D geometric spreading have been thoroughly discussed (see Helgesen, 1990; Wapenaar et al., 1990, 1992; Herrmann, 1992; Helgesen and Kolb, 1993; Amundsen, 1993). In the case of cylindrical symmetry this transformation constitutes a required preprocessing step for several seismic processing algorithms based on 2-D wave propagation. The work of Dampney (1971) has apparently been missed by the authors discussing the 3-D to 2-D geometric spreading transform.

Wavenumber‐based filtering of marine point‐source data

Geophysics ◽  
1993 ◽  
Vol 58 (9) ◽  
pp. 1335-1348 ◽  
Author(s):  
Lasse Amundsen
Keyword(s):  
Plane Wave ◽  
Point Source ◽  
Line Source ◽  
Hankel Transform ◽  
Source Pressure ◽  
Function Type ◽  
Plane Wave Decomposition ◽  
Source Data ◽  
Processing Techniques ◽  
Wave Decomposition

In seismic processing, plane‐wave decomposition has played a fundamental role, serving as a basis for developing sophisticated processing techniques valid for depth‐dependent models. By comparing analytical expressions for the decomposed wavefields, we review several processing algorithms of interest for the geophysicist. The algorithms may be applied to marine point‐source data acquired over a horizontally layered viscoelastic and anisotropic medium. The plane‐wave decomposition is based on the Fourier transform integral for line‐source data and the Hankel transform integral for point‐source data. The involved wavenumber integrals of the cosine or Bessel‐function type are difficult to evaluate accurately and efficiently. However, a number of the processing techniques can easily be run as a filtering operation in the spatial domain without transforming to the wavenumber domain. The mathematical expressions for the spatial filters are derived using plane wave analysis. With numerical examples, we demonstrate the separation of upgoing and downgoing waves from the pressure, the removal of the source ghost from the pressure, and the transformation of point‐source pressure data to the corresponding line‐source data. The filters for these three processes work satisfactorily. Limited spatial aperture is discussed both for point‐source and line‐source data. The resolution kernels relating finite‐aperture decomposed data to infinite‐aperture decomposed data are given. The kernels are approximately equal in the asymptotic limit when the minimum offset is zero.

Frequency-domain seismic data transformation from point-source to line-source for 2D viscoelastic anisotropic media

Geophysics ◽  
2021 ◽  
pp. 1-45
Author(s):  
Qingjie Yang ◽  
Bing Zhou ◽  
Mohamed Kamel Riahi ◽  
Mohammad Al-Khaleel
Keyword(s):  
Phase Shift ◽  
Point Source ◽  
Seismic Data ◽  
Line Source ◽  
Waveform Inversion ◽  
Full Waveform ◽  
Compensation Factor ◽  
Source Data ◽  
Amplitude Compensation ◽  
Homogeneous Media

We present a simple yet effective transform function to convert 3D point-source seismic data to equivalent 2D line-source data, which is required when applying efficient 2D migration and full-waveform inversion to field data collected along a line. By numerically comparing the 3D and corresponding 2D Green’s tensors in various media, the phase shift around 45° and the offset amplitude compensation factor, as well as small fluctuations of the amplitude ratios are observed in all nonzero components of the wave-equation solutions. Based on these observations, we derive a transform function comprised of (1) a simple filter for compensating amplitude and phase shift, and (2) stretching scalars for scaling amplitude differences for different components. We employ the 3D and 2D analytical wave solutions in various homogeneous media to demonstrate the accuracy of the proposed transform function, and then apply it to a heterogeneous, viscoelastic, anisotropic model and a modified Marmousi model. All of these results indicate that the proposed transform function is applicable for the conversion of point-source data to equivalent line-source data for imaging 2D subsurface structure.

DEVELOPMENTS IN SEISMIC DATA PROCESSING AND ANALYSIS (1968–1970)

Geophysics ◽  
1971 ◽  
Vol 36 (6) ◽  
pp. 1043-1073 ◽  
Author(s):  
William A. Schneider
Keyword(s):  
Data Processing ◽  
Seismic Data ◽  
Model Building ◽  
Processing Parameters ◽  
Subject Area ◽  
Two Dimensions ◽  
Seismic Data Processing ◽  
Seismic Processing ◽  
Reflection Seismic ◽  
Stratigraphic Model

The subject matter of this review paper pertains to developments during the past several years in the area of reflection seismic data processing and analysis. While this subject area is extensive in both its breadth and scope, one indisputable fact emerges: the computer is now more pervasive than ever. Processing areas which were computer intensive, such as signal enhancement, are now even more so; and those formerly exclusive domains of man, such as seismic interpretation, are beginning to feel the encroachment of the large number crunchers. What the future holds is anyone’s guess, but it is quite probable that man and computer will share the throne if the interactive seismic processing systems on the drawing boards come to pass. For the present and recent past, however, the most intensively developed areas of seismic data processing and analysis include 1) computer extraction of processing parameters such as stacking velocity and statics, 2) automated detection and tracking of reflections in multidimensional parameter space to provide continuous estimates of traveltime, amplitude, moveout (velocity), dip, etc., 3) direct digital migration in two dimensions, giving improved subsurface “pictures” and utilizing diffraction energy normally lost by specular processing techniques, and 4) development of quantitative understanding of the limitations imposed by current seismic processing practice and assumptions with regard to structural and stratigraphic model building, and recognition of the ultimate need for an iterative signal processing—information extraction—model building closed loop system.

scholarly journals Multiscale phase inversion of seismic data

Geophysics ◽  
2018 ◽  
Vol 83 (2) ◽  
pp. R159-R171 ◽  
Author(s):  
Lei Fu ◽  
Bowen Guo ◽  
Gerard T. Schuster
Keyword(s):  
Seismic Data ◽  
Phase Inversion ◽  
Input Data ◽  
Waveform Inversion ◽  
Data Set ◽  
Acoustic Data ◽  
Full Waveform ◽  
Elastic Data ◽  
Mpi Implementation ◽  
Starting Model

We present a scheme for multiscale phase inversion (MPI) of seismic data that is less sensitive than full-waveform inversion (FWI) to the unmodeled physics of wave propagation and to a poor starting model. To avoid cycle skipping, the multiscale strategy temporally integrates the traces several times, i.e., high-order integration, to produce low-boost seismograms that are used as input data for the initial iterations of MPI. As the iterations proceed, lower frequencies in the data are boosted by using integrated traces of lower order as the input data. The input data are also filtered into different narrow frequency bands for the MPI implementation. Numerical results with synthetic acoustic data indicate that, for the Marmousi model, MPI is more robust than conventional multiscale FWI when the initial model is moderately far from the true model. Results from synthetic viscoacoustic and elastic data indicate that MPI is less sensitive than FWI to some of the unmodeled physics. Inversion of marine data indicates that MPI is more robust and produces modestly more accurate results than FWI for this data set.

APPLICATION OF THE EMPIRICAL MODE DECOMPOSITION METHOD TO GROUND-ROLL NOISE ATTENUATION IN SEISMIC DATA

2013 ◽  
Vol 31 (4) ◽  
pp. 619 ◽  
Author(s):  
Luiz Eduardo Soares Ferreira ◽  
Milton José Porsani ◽  
Michelângelo G. Da Silva ◽  
Giovani Lopes Vasconcelos
Keyword(s):  
Empirical Mode Decomposition ◽  
Seismic Data ◽  
Low Frequency ◽  
High Amplitude ◽  
Seismic Line ◽  
Seismic Processing ◽  
Mode Decomposition ◽  
Ground Roll ◽  
Fortran 90 ◽  
Emd Method

ABSTRACT. Seismic processing aims to provide an adequate image of the subsurface geology. During seismic processing, the filtering of signals considered noise is of utmost importance. Among these signals is the surface rolling noise, better known as ground-roll. Ground-roll occurs mainly in land seismic data, masking reflections, and this roll has the following main features: high amplitude, low frequency and low speed. The attenuation of this noise is generally performed through so-called conventional methods using 1-D or 2-D frequency filters in the fk domain. This study uses the empirical mode decomposition (EMD) method for ground-roll attenuation. The EMD method was implemented in the programming language FORTRAN 90 and applied in the time and frequency domains. The application of this method to the processing of land seismic line 204-RL-247 in Tacutu Basin resulted in stacked seismic sections that were of similar or sometimes better quality compared with those obtained using the fk and high-pass filtering methods.Keywords: seismic processing, empirical mode decomposition, seismic data filtering, ground-roll. RESUMO. O processamento sísmico tem como principal objetivo fornecer uma imagem adequada da geologia da subsuperfície. Nas etapas do processamento sísmico a filtragem de sinais considerados como ruídos é de fundamental importância. Dentre esses ruídos encontramos o ruído de rolamento superficial, mais conhecido como ground-roll . O ground-roll ocorre principalmente em dados sísmicos terrestres, mascarando as reflexões e possui como principais características: alta amplitude, baixa frequência e baixa velocidade. A atenuação desse ruído é geralmente realizada através de métodos de filtragem ditos convencionais, que utilizam filtros de frequência 1D ou filtro 2D no domínio fk. Este trabalho utiliza o método de Decomposição em Modos Empíricos (DME) para a atenuação do ground-roll. O método DME foi implementado em linguagem de programação FORTRAN 90, e foi aplicado no domínio do tempo e da frequência. Sua aplicação no processamento da linha sísmica terrestre 204-RL-247 da Bacia do Tacutu gerou como resultados, seções sísmicas empilhadas de qualidade semelhante e por vezes melhor, quando comparadas as obtidas com os métodos de filtragem fk e passa-alta.Palavras-chave: processamento sísmico, decomposição em modos empíricos, filtragem dados sísmicos, atenuação do ground-roll.

Reducing risk and improving production in unconventional plays

2013 ◽  
Vol 1 (2) ◽  
pp. SB3-SB14 ◽  
Author(s):  
Tony Rebec ◽  
Marino Pareja ◽  
Zhiyong Zhao
Keyword(s):  
Seismic Data ◽  
Seismic Processing ◽  
Business Values ◽  
Improve Production ◽  
Reduce Risk ◽  
The Right

Using seismic data to reduce risk and improve production in unconventional plays requires careful preplanning based on the nature of the play, plus acquiring the right seismic, processing the seismic correctly, extracting the optimum information, and then transforming the information into business values. We discuss these criteria and focus on extracting the optimum information.

Electron Acceleration in Collapsing Magnetic Traps during the Solar Flare on July 19, 2012: Observations and Models

2017 ◽  
Vol 13 (S335) ◽  
pp. 90-93
Author(s):  
P. A. Gritsyk ◽  
B. V. Somov
Keyword(s):  
Point Source ◽  
Solar Flares ◽  
High Efficiency ◽  
Reverse Current ◽  
Electron Acceleration ◽  
Thick Target ◽  
Two Dimensions ◽  
Magnetic Traps ◽  
Thin Target ◽  
X Ray

AbstractUsing the appropriate kinetic equation, we considered the problem of propagation of accelerated electrons into the solar corona and chromosphere. Its analytical solution was used for modelling the M7.7 class limb flare occurred on July 19, 2012. Coronal above-the-loop-top hard X-Ray source was interpreted in the thin-target approximation, the foot-point source - in the thick-target approximation with account of the reverse-current electric field. For the foot-point source we found a good accordance with the RHESSI observations. For the coronal source we also got very accurate estimate of the power-law spectral index, but significant differences between the modelled and observed hard X-ray intensities were noticed. The last discrepancy was solved by adding the coronal magnetic trap model to the thin target model. The former one implies that the trap collapses in two dimensions, locks and accelerates particles inside itself. In our report, we confirm an existence and high efficiency of the electron acceleration in collapsing magnetic traps during solar flares. Our new results represent (e.g. for RHESSI observations) the theoretical prediction of the double step particle acceleration in solar flares, when the first step is the acceleration in reconnection area and the second one – the acceleration in coronal trap.

High-resolution seismic processing technique with broadband,wide-azimuth, and high-density seismic data - A case study of thin-sand reservoir in eastern China

2021 ◽  
pp. 1-45
Author(s):  
Qin Su ◽  
Huahui Zeng ◽  
Yancan Tian ◽  
HaiLiang Li ◽  
Lei Lyu ◽  
...  
Keyword(s):  
Seismic Data ◽  
Oil And Gas ◽  
Single Point ◽  
Eastern China ◽  
High Density ◽  
Songliao Basin ◽  
Seismic Processing ◽  
Oil And Gas Exploration ◽  
Sand Body

Seismic processing and interpretation techniques provide important tools for the oil and gas exploration of the Songliao Basin in eastern China, which is dominated by terrestrial facies. In the Songliao Basin, a large number of thin-sand reservoirs are widely distributed, which are the primary targets of potential oil and gas exploration and exploitation. An important job of the exploration in the Songliao Basin is to accurately describe the distribution of these thin-sand belts and the sand-body shapes. However, the thickness of these thin-sand reservoirs are generally below the resolution of the conventional seismic processing. Most of the reservoirs are thin-interbeds of sand and mudstones with strong vertical and lateral variations. This makes it difficult to accurately predict the vertical and horizontal distribution of the thin-sand bodies using the conventional seismic processing and interpretation methods. Additionally, these lithologic traps are difficult to identify due to the complex controlling factor and distribution characteristics, and strong concealment. These challenges motivate us to improve the seismic data quality to help delineate the thin-sand reservoirs. In this paper, we use the broadband, wide-azimuth, and high-density integrated seismic exploration technique to help delineate the thin-reservoirs. We first use field single-point excitation and single-point receiver acquisition to obtain seismic data with wide frequency-bands, wide-azimuth angles, and high folds, which contain rich geological information. Next, we perform the near-surface Q-compensation, viscoelastic prestack time migration, seismic attributes, and seismic waveform indication inversion on the new acquired seismic data. The 3D case study indicates the benefits of improving the imaging of thin-sand body and the accuracy of inversion and reservoir characterization using the method in this paper.

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