Download or read book 3D Elastic Full Waveform Inversion for Subsurface Characterization Study of a Shallow Seismic Multicomponent Field Data written by Theodosius Marwan Irnaka and published by . This book was released on 2021 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Full Waveform Inversion (FWI) is an iterative data fitting procedure between the observed data and the synthetic data. The synthetic data is calculated by solving the wave equation. FWI aims at reconstructing the detailed information of the subsurface physical properties. FWI has been rapidly developed in the past decades, thanks to the increase of the computational capability and the development of the acquisition technology. FWI also has been applied in a broad scales including the global, lithospheric, crustal, and near surface scale.In this manuscript, we investigate the inversion of a multicomponent source and receiver near-surface field dataset using a viscoelastic full waveform inversion algorithm for a shallow seismic target. The target is a trench line buried at approximately 1 m depth. We present the pre-processing of the data, including a matching filter correction to compensate for different source and receiver coupling conditions during the acquisition, as well as a dedicated multi-step workflow for the reconstruction of both P-wave and S-wave velocities. Our implementation is based on viscoelastic modeling using a spectral element discretization to accurately account for the wave propagation's complexity in this shallow region. We illustrate the inversion stability by starting from different initial models, either based on dispersion curve analysis or homogeneous models consistent with first arrivals. We recover similar results in both cases. We also illustrate the importance of taking into account the attenuation by comparing elastic and viscoelastic results. The 3D results make it possible to recover and locate precisely the trench line in terms of interpretation. They also exhibit another trench line structure, in a direction forming an angle at 45 degrees with the direction of the targeted trench line. This new structure had been previously interpreted as an artifact in former 2D inversion results. The archaeological interpretation of this new structure is still a matter of discussion.We also perform three different experiments to study the effect of multicomponent data on this FWI application. The first experiment is a sensitivity kernel analysis of several wave packets (P-wave, S-wave, and surface wave) on a simple 3D model based on a Cartesian based direction of source and receiver. The second experiment is 3D elastic inversion based on synthetic (using cartesian direction's source) and field data (using Galperin source) with various component combinations. Sixteen component combinations are analyzed for each case. In the third experiment, we perform the acquisition's decimation based on the second experiment. We demonstrate a significant benefit of multicomponent data FWI in terms of model and data misfit through those experiments. In a shallow seismic scale, the inversions with the horizontal components give a better depth reconstruction. Based on the acquisition's decimation, inversion using heavily decimated 9C seismic data still produce similar results compared to the inversion using 1C seismic of a dense acquisition.

Download or read book Elastic Waveform Inversion with Compressive Sensing for Sparse Seismic Data written by and published by . This book was released on 2015 with total page 7 pages. Available in PDF, EPUB and Kindle. Book excerpt: Accurate velocity models of compressional- and shear-waves are essential for geothermal reservoir characterization and microseismic imaging. Elastic-waveform inversion of multi-component seismic data can provide high-resolution inversion results of subsurface geophysical properties. However, the method requires seismic data acquired using dense source and receiver arrays. In practice, seismic sources and/or geophones are often sparsely distributed on the surface and/or in a borehole, such as 3D vertical seismic profiling (VSP) surveys. We develop a novel elastic-waveform inversion method with compressive sensing for inversion of sparse seismic data. We employ an alternating-minimization algorithm to solve the optimization problem of our new waveform inversion method. We validate our new method using synthetic VSP data for a geophysical model built using geologic features found at the Raft River enhanced-geothermal-system (EGS) field. We apply our method to synthetic VSP data with a sparse source array and compare the results with those obtained with a dense source array. Our numerical results demonstrate that the velocity models produced with our new method using a sparse source array are almost as accurate as those obtained using a dense source array.

Download or read book Multi component Seismic Modeling and Robust Pre stack Seismic Waveform Inversion for Elastic Anisotropic Media Parameters written by Tao Li and published by . This book was released on 2016 with total page 124 pages. Available in PDF, EPUB and Kindle. Book excerpt: Consideration of azimuthal anisotropy, at least to an orthorhombic symmetry is important in exploring the naturally fractured and unconventional hydrocarbon reservoirs. Full waveform inversion of multicomponent seismic data can, in principle, provide more robust estimates of subsurface elastic parameters and density than the inversion of single component (P wave) seismic data. In addition, azimuthally dependent anisotropy can only be resolved by carefully studying the multicomponent seismic displacement data acquired and processed along different azimuths. Such an analysis needs an inversion algorithm capable of simultaneously optimizing multiple objectives, one for each data component along each azimuth. In this dissertation, I propose a novel multiobjective methodology using a parallelized version of NSGA II for waveform inversion of multicomponent seismic data along two azimuths. The proposed methodology is also an improvement of the original NSGA II in overall computational efficiency, preservation of population diversity, and rapid sampling of the model space. Next, the proposed methodology is applied on wide azimuth and multicomponent vertical seismic profile (VSP) data to provide reliable estimation of subsurface anisotropy at and near the well location. Prestack waveform inversion was applied to the wide-azimuth multicomponent VSP data acquired at the Wattenberg Field, located in Denver Basin of northeastern Colorado, USA, to characterize the Niobrara formation for azimuthal anisotropy. By comparing the waveform inversion results with an independent study that used a joint slowness-polarization approach to invert the same data, we conclude that the waveform inversion is a reliable tool for inverting the wide-azimuth multicomponent VSP data for anisotropy estimation. Last but not least, an anisotropic elastic three-dimensional scheme for modeling the elastodynamic wavefield is developed in order to go beyond the 1D layering assumption being used in previous studies. The method uses quadratic tetrahedral elements to discretize the model in space, Newmark family of time integration scheme to discretize in time, and a perfectly matched layer as the absorbing boundary condition. Various preconditioned conjugate gradient approaches were tested and implemented in the algorithm to improve the numerical efficiency of the finite element solver and the entire methodology was optimized to run efficiently in a parallel computing architecture. By computing synthetic seismic responses for a homogeneous medium and for a layered anisotropic medium and comparing results with other analytical and numerical solutions, the validity of the methodology was also verified for numerical accuracy.

Download or read book Land Seismic Case Studies for Near Surface Modeling and Subsurface Imaging written by Öz Yilmaz and published by SEG Books. This book was released on 2021-06-30 with total page 1056 pages. Available in PDF, EPUB and Kindle. Book excerpt: Written for practicing geophysicists, “Land Seismic Case Studies for Near-Surface Modeling and Subsurface Imaging” is a comprehensive guide to understanding and interpreting seismic data. The culmination of land seismic data acquisition and processing projects conducted by the author over the last two decades, this book contains more than nearly 800 figures from worldwide case studies—conducted in both 2D and 3D. Beginning with Chapter 1 on seismic characterization of the near-surface, Chapter 2 presents near-surface modeling by traveltime and full-wave inversion, Chapter 3 presents near-surface modeling by imaging, and then Chapter 4 includes detailed case studies for near-surface modeling. Chapter 5 reviews single- and multichannel signal processing of land seismic data with the key objective of removing surface waves and guided waves that are characterized as coherent linear noise. Uncommon seismic data acquisition methods, including large-offset acquisition in thrust belts to capture the large-amplitude supercritical reflections, swath-line acquisition, and joint PP and SH- SH seismic imaging are highlighted in Chapter 6, and Chapter 7 presents image-based rms velocity estimation and discusses the problem of velocity uncertainty. The final two chapters focus exclusively on case studies: 2D in Chapter 8 and 3D in Chapter 9. An outstanding teaching tool, this book includes analysis workflows containing processing steps designed to solve specific problems. Essential for anyone involved in acquisition, processing, and inversion of seismic data, this volume will become the definitive reference for understanding how the variables in seismic acquisition are directly reflected in the data.

Download or read book 3D Elastic Full waveform Inversion written by Lluis Guasch and published by . This book was released on 2012 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Full Waveform Inversion (FWI) is a depth imaging technique that takes advantage of the full information contained in recorded seismic data. FWI provide high resolution images of subsurface properties, usually seismic velocities or related parameters, although in theory it could image any property used to formulate the wave equation. The computational cost of the methodology has historically limited its application to 3D acoustic approximations but recent developments in hardware capabilities have increased computer power to the point that more realistic approximations are viable. In this work the traditional acoustic approximation is extended to include elastic effects by introducing the elastic wave equation as the governing law that describes wave propagation. I have developed a software based on finite-differences to solve the elastic wave equation in 3D, which I applied in the development of a full-waveform inversion algorithm. The software is fully parallelised for both distributed and shared-memory systems. The first level of parallelisation distributes seismic sources across cluster nodes. Each node solves the 3D elastic wave equation in the whole computational domain. The second level of parallelisation takes advantage of present multi-core computer processor units (CPU) to decompose the computational domain into different volumes that are solved independently by each core. Such parallel design allows the algorithm to handle models of realistic sizes, increasing the computational times only a factor of two compared to those of 3D acoustic full-waveform inversion on the same mesh. I have also implemented a perfectly matched layer absorbing boundary condition to reproduce a semi-infinite model geometry and prevent spurious reflections from the model boundaries from contaminating the modelled wavefields. The inversion algorithm is based upon the adjoint-state method, which I reformulated for the wave equation that I implemented, which was based on particle-velocities and stresses, providing a comparison and demonstration of equivalence with previous developments. To examine the performance of the code, I have inverted several synthetic problems of increasing realism. I have principally used only pressure sources and receivers to assess the potential of the method's application to the most common industry surveys: streamer data for offshore and vertical geophones (only one component) for onshore exploration surveys. The results show that the imaged properties increase with the heterogeneity of the models, due to the increase in P-S-P conversions which provides the main source of information to invert shear-wave velocity models from pressure sources and receivers. It remains to demonstrate the inversion of field datasets and my future research project will focused on achieving this goal.

Download or read book Full waveform Inversion to 3D Seismic Land Data written by Ahmed Musallam Ali Al-Yaqoobi and published by . This book was released on 2013 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Full-waveform inversion (FWI) is a technique that seeks to find a high-resolution high-fidelity model of the Earth's subsurface that is capable of matching individual seismic waveforms, within an original raw field dataset, trace by trace. The method begins from a best-guess starting model, which is then iteratively improved using a sequence of linearized local inversions to solve a fully non-linear problem. In principle, FWI can be used to recover any physical property that has an influence upon the seismic wavefield, but in practice the technique has been used predominantly to recover P-wave velocity, and this is the route that is followed here. Full-waveform tomographic techniques seek to determine a highly resolved quantitative model of the sub-surface that will ultimately be able to explain the entire seismic wavefield including those phases that conventional processing and migration seek to remove such as refracted arrivals. Although the underlying theory of FWI is well established, its practical application to 3D land data, and especially to seismic data that have been acquired using vibrators, in a form that is effective and robust, is still a subject of intense research. In this study, 2D and 3D FWI techniques have been applied to a vibrator dataset from onshore Oman. Both the raw dataset and the subsurface model cause difficulties for FWI. In particular, the data are noisy, have weak early arrivals, are strongly elastic, and especially are lacking in low-frequency content. The Earth model appears to contain shallow low-velocity layers, and these compromise the use of first-arrival travel-time tomography for the generation of a starting velocity model. The 2D results show good recovery of the shallow part of the velocity models. The results show a low-velocity layer that extends across the velocity model, but lacking in a high-resolution image due to the absence of the third dimension. The seismograms of the final inversion models give a good comparison with the field data and produce a reasonably high correlation coefficient compared to the starting model. An inversion scheme has been developed in this study in which only data from the shorter offsets are initially inverted since these represent the subset of the data that is not cycle skipped. The offset range is then gradually extended as the model improves. The final 3D model contains a strongly developed low-velocity layer in the shallow section. The results from this inversion appear to match p-wave logs from a shallow drill hole, better flatten the gathers, and better stack and migrate the reflection data. The inversion scheme is generic, and should have applications to other similar difficult datasets.

Download or read book Shared Earth Modeling written by John R. Fanchi and published by Elsevier. This book was released on 2002-08-25 with total page 319 pages. Available in PDF, EPUB and Kindle. Book excerpt: Shared Earth Modeling introduces the reader to the processes and concepts needed to develop shared earth models. Shared earth modeling is a cutting-edge methodology that offers a synthesis of modeling paradigms to the geoscientist and petroleum engineer to increase reservoir output and profitability and decrease guesswork. Topics range from geology, petrophysics, and geophysics to reservoir engineering, reservoir simulation, and reservoir management.Shared Earth Modeling is a technique for combining the efforts of reservoir engineers, geophysicists, and petroleum geologists to create a simulation of a reservoir. Reservoir engineers, geophysicists, and petroleum geologists can create separate simulations of a reservoir that vary depending on the technology each scientist is using. Shared earth modeling allows these scientists to consolidate their findings and create an integrated simulation. This gives a more realistic picture of what the reservoir actually looks like, and thus can drastically cut the costs of drilling and time spent mapping the reservoir. First comprehensive publication about Shared Earth Modeling Details cutting edge methodology that provides integrated reservoir simulations

Download or read book Geophysics and Geosequestration written by Thomas L. Davis and published by Cambridge University Press. This book was released on 2019-05-09 with total page 391 pages. Available in PDF, EPUB and Kindle. Book excerpt: An overview of the geophysical techniques and analysis methods for monitoring subsurface carbon dioxide storage for researchers and industry practitioners.

Download or read book Full 3D Seismic Waveform Inversion written by Po Chen and published by Springer. This book was released on 2015-09-10 with total page 543 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book introduces a methodology for solving the seismic inverse problem using purely numerical solutions built on 3D wave equations and which is free of the approximations or simplifications that are common in classical seismic inversion methodologies and therefore applicable to arbitrary 3D geological media and seismic source models. Source codes provided allow readers to experiment with the calculations demonstrated and also explore their own applications.

Download or read book Wavefield Inversion written by Armand Wirgin and published by Springer Science & Business Media. This book was released on 2000-04-19 with total page 320 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book provides an up-to-date presentation of a broad range of contemporary problems in inverse scattering involving acoustic, elastic and electromagnetic waves. Descriptions will be given of traditional (but still in use and subject to on-going improvements) and more recent methods for identifying either: a) the homogenized material parameters of (spatially) unbounded or bounded heterogeneous media, or b) the detailed composition (spatial distribution of the material parameters) of unbounded or bounded heterogeneous media, or c) the location, shape, orientation and material characteristics of an object embedded in a wellcharacterized homogeneous, homogenized or heterogeneous unbounded or bounded medium, by inversion of reflected, transmitted or scattered spatiotemporal recorded waveforms resulting from the propagation of probe radiation within the medium.

Download or read book Full Seismic Waveform Modelling and Inversion written by Andreas Fichtner and published by Springer Science & Business Media. This book was released on 2010-11-16 with total page 352 pages. Available in PDF, EPUB and Kindle. Book excerpt: Recent progress in numerical methods and computer science allows us today to simulate the propagation of seismic waves through realistically heterogeneous Earth models with unprecedented accuracy. Full waveform tomography is a tomographic technique that takes advantage of numerical solutions of the elastic wave equation. The accuracy of the numerical solutions and the exploitation of complete waveform information result in tomographic images that are both more realistic and better resolved. This book develops and describes state of the art methodologies covering all aspects of full waveform tomography including methods for the numerical solution of the elastic wave equation, the adjoint method, the design of objective functionals and optimisation schemes. It provides a variety of case studies on all scales from local to global based on a large number of examples involving real data. It is a comprehensive reference on full waveform tomography for advanced students, researchers and professionals.

Download or read book Seismic Inversion Methods A Practical Approach written by S. P. Maurya and published by Springer Nature. This book was released on 2020-05-28 with total page 221 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book introduces readers to seismic inversion methods and their application to both synthetic and real seismic data sets. Seismic inversion methods are routinely used to estimate attributes like P-impedance, S-impedance, density, the ratio of P-wave and S-wave velocities and elastic impedances from seismic and well log data. These attributes help to understand lithology and fluid contents in the subsurface. There are several seismic inversion methods available, but their application and results differ considerably, which can lead to confusion. This book explains all popular inversion methods, discusses their mathematical backgrounds, and demonstrates their capacity to extract information from seismic reflection data. The types covered include model-based inversion, colored inversion, sparse spike inversion, band-limited inversion, simultaneous inversion, elastic impedance inversion and geostatistical inversion, which includes single-attribute analysis, multi-attribute analysis, probabilistic neural networks and multi-layer feed-forward neural networks. In addition, the book describes local and global optimization methods and their application to seismic reflection data. Given its multidisciplinary, integrated and practical approach, the book offers a valuable tool for students and young professionals, especially those affiliated with oil companies.

Download or read book Seismic Full Waveform Inversion written by Dongzhuo Li and published by . This book was released on 2019 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: I present three topics in the area of theoretical development and application of Full Waveform Inversion (FWI). The first topic or contribution describes a learning-based adaptive and sparsity promoting regularization method to improve the accuracy of traditional FWI results with the prior knowledge of nonlocal similarity in geological structures. Such a priori is realized by multi-class orthogonal dictionary learning. The second topic extends the learning-based regularization to elastic waves and applies the approach to a field dataset to estimate P-wave and S-wave velocities. This topic highlights the importance of data pre-processing and modification of the FWI algorithm to accommodate field data issues such as radiation pattern estimation, wavelet estimation, and amplitude scaling. The aim of this part is high-resolution reservoir characterization, which is not only an extension of the technique in the first part but also serves as a preparation for the time-lapse inversion in the third part. In the third topic, I describe a framework for using FWI to estimate hidden parameters that are important to geophysical processes such as fluid flow in porous media. This framework extends the power of FWI beyond seismology to other geophysical problems such as reservoir engineering and hydrology by combining seismic observations, rock properties modeling, and flow modeling. This third topic represents a PDE-constrained inverse problem that I solve with an intelligent automatic differentiation method. The method provides three levels of user control with (1) built-in differentiable operators from modern deep-learning infrastructures, and customized operators that can either (2) encapsulate analytic adjoint gradient computation or (3) handle the forward simulation and compute the corresponding gradient for a single time step. This intelligent strategy strikes a good balance between computational efficiency and programming efficiency and would serve as a paradigm for a wide range of PDE-constrained geophysical inverse problems.

Download or read book Elements of 3D Seismology third edition written by Christopher L. Liner and published by SEG Books. This book was released on 2016-10-15 with total page 363 pages. Available in PDF, EPUB and Kindle. Book excerpt: Elements of 3D Seismology, third edition is a thorough introduction to the acquisition, processing, and interpretation of 3D seismic data. This third edition is a major update of the second edition. Sections dealing with interpretation have been greatly revised in accordance with improved understanding and availability of data and software. Practice exercises have been added, as well as a 3D seismic survey predesign exercise. Discussions include: conceptual and historical foundations of modern reflection seismology; an overview of seismic wave phenomena in acoustic, elastic, and porous media; acquisition principles for land and marine seismic surveys; methods used to create 2D and 3D seismic images from field data; concepts of dip moveout, prestack migration, and depth migration; concepts and limitations of 3D seismic interpretation for structure, stratigraphy, and rock property estimation; and the interpretation role of attributes, impedance estimation, and AVO. This book is intended as a general text on reflection seismology, including wave propagation, data acquisition, processing, and interpretation and will be of interest to entry-level geophysicists, experts in related fields (geology, petroleum engineering), and experienced geophysicists in one subfield wishing to learn about another (e.g., interpreters wanting to learn about seismic waves or data acquisition).

Download or read book Numerical Optimization written by Joseph-Frédéric Bonnans and published by Springer Science & Business Media. This book was released on 2013-03-14 with total page 421 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book starts with illustrations of the ubiquitous character of optimization, and describes numerical algorithms in a tutorial way. It covers fundamental algorithms as well as more specialized and advanced topics for unconstrained and constrained problems. This new edition contains computational exercises in the form of case studies which help understanding optimization methods beyond their theoretical description when coming to actual implementation.

Download or read book Treatise on Geophysics written by and published by Elsevier. This book was released on 2015-04-17 with total page 5604 pages. Available in PDF, EPUB and Kindle. Book excerpt: Treatise on Geophysics, Second Edition, is a comprehensive and in-depth study of the physics of the Earth beyond what any geophysics text has provided previously. Thoroughly revised and updated, it provides fundamental and state-of-the-art discussion of all aspects of geophysics. A highlight of the second edition is a new volume on Near Surface Geophysics that discusses the role of geophysics in the exploitation and conservation of natural resources and the assessment of degradation of natural systems by pollution. Additional features include new material in the Planets and Moon, Mantle Dynamics, Core Dynamics, Crustal and Lithosphere Dynamics, Evolution of the Earth, and Geodesy volumes. New material is also presented on the uses of Earth gravity measurements. This title is essential for professionals, researchers, professors, and advanced undergraduate and graduate students in the fields of Geophysics and Earth system science. Comprehensive and detailed coverage of all aspects of geophysics Fundamental and state-of-the-art discussions of all research topics Integration of topics into a coherent whole

Download or read book Elastic Wave Field Extrapolation written by C.P.A. Wapenaar and published by Elsevier. This book was released on 2014-04-14 with total page 485 pages. Available in PDF, EPUB and Kindle. Book excerpt: Extrapolation of seismic waves from the earth's surface to any level in the subsurface plays an essential role in many advanced seismic processing schemes, such as migration, inverse scattering and redatuming. At present these schemes are based on the acoustic wave equation. This means not only that S-waves (shear waves) are ignored, but also that P-waves (compressional waves) are not handled correctly. In the seismic industry there is an important trend towards multi-component data acquisition. For processing of multi-component seismic data, ignoring S-waves can no longer be justified. Wave field extrapolation should therefore be based on the full elastic wave equation.In this book the authors review acoustic one-way extrapolation of P-waves and introduce elastic one-way extrapolation of P- and S-waves. They demonstrate that elastic extrapolation of multi-component data, decomposed into P- and S-waves, is essentially equivalent to acoustic extrapolation of P-waves. This has the important practical consequence that elastic processing of multi-component seismic data need not be significantly more complicated than acoustic processing of single-component seismic data. This is demonstrated in the final chapters, which deal with the application of wave field extrapolation in the redatuming process of single- and multi-component seismic data. Geophysicists, and anyone who is interested in a review of acoustic and elastic wave theory, will find this book useful. It is also a suitable textbook for graduate students and those following courses in elastic wave field extrapolation as each subject is introduced in a relatively simple manner using the scalar acoustic wave equation. In the chapters on elastic wave field extrapolation the formulation, whenever possible, is analogous to that used in the chapters on acoustic wave field extrapolation. The text is illustrated throughout and a bibliography and keyword index are provided.