Seismology of Azimuthally Anisotropic Media and Seismic Fracture Characterization

Seismology of Azimuthally Anisotropic Media and Seismic Fracture Characterization PDF

Author: I. D. T︠S︡vankin

Publisher: SEG Books

Published: 2011

Total Pages: 512

ISBN-13: 1560802286

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Presents an analysis of seismic signatures for azimuthally anisotropic media and shows anisotropic inversion/processing methods for wide-azimuth reflection data and VSP surveys. The focus is kinematic parameter-estimation techniques; the prestack amplitudes section includes AVO and attenuation coefficients; field examples are included.

Seismic Fracture Characterization

Seismic Fracture Characterization PDF

Author: Enru Liu

Publisher:

Published: 2012

Total Pages: 279

ISBN-13: 9789073834408

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During the last three decades, seismic anisotropy has evolved from a purely academic research topic into applications in the mainstream of applied geophysics. Today, nobody doubts that the earth is anisotropic and most (if not all) hydrocarbon reservoirs are anisotropic. Since shale accounts for 70% of sedimentary basins and fractures exist in all reservoirs, seismic anisotropy may be even more extensive than we think. Taking anisotropy into account in seismic processing has improved the quality of seismic images, even though it makes seismic processing more challenging since additional parameters are needed. At the same time, fracture characterization using the concept of seismic anisotropy has added value in reservoir characterization, reservoir management, and has increased recovery and optimized well locations. This book and the associated course provide an introduction to the fundamental concepts of seismic fracture characterization by introducing seismic anisotropy, equivalent-medium representation theories of fractured rock and methodologies for extracting fracture parameters from seismic data. We focus on practical applications using extensive field data examples. Includes cast studies demonstrating the applicability, workflow and limitations of this technologyContains physical laboratory 3D experiments where fracture distributions are known, a Middle East fractured carbonate reservoir and a fractured tight gas reservoir. Builds discrete fracture network models incorporating all data. These models should not only be geologically consistent but also geophysically and geomechanically consistent, so that the models can be used to forecast the behaviour and performance of fractured reservoirs.

Seismic Fracture Characterization

Seismic Fracture Characterization PDF

Author: Enru Liu

Publisher: Academic Press

Published: 2013-12-06

Total Pages:

ISBN-13: 9073834503

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During the last three decades, seismic anisotropy has evolved from a purely academic research topic into applications in the mainstream of applied geophysics. Today, nobody doubts that the earth is anisotropic and most (if not all) hydrocarbon reservoirs are anisotropic. Since shale accounts for 70% of sedimentary basins and fractures exist in all reservoirs, seismic anisotropy may be even more extensive than we think. Taking anisotropy into account in seismic processing has improved the quality of seismic images, even though it makes seismic processing more challenging since additional parameters are needed. At the same time, fracture characterization using the concept of seismic anisotropy has added value in reservoir characterization, reservoir management, and has increased recovery and optimized well locations. This book and the associated course provide an introduction to the fundamental concepts of seismic fracture characterization by introducing seismic anisotropy, equivalent-medium representation theories of fractured rock and methodologies for extracting fracture parameters from seismic data. We focus on practical applications using extensive field data examples. Includes cast studies demonstrating the applicability, workflow and limitations of this technology Contains physical laboratory 3D experiments where fracture distributions are known, a Middle East fractured carbonate reservoir and a fractured tight gas reservoir. Builds discrete fracture network models incorporating all data. These models should not only be geologically consistent but also geophysically and geomechanically consistent, so that the models can be used to forecast the behaviour and performance of fractured reservoirs.

Seismic Signatures and Analysis of Reflection Data in Anisotropic Media

Seismic Signatures and Analysis of Reflection Data in Anisotropic Media PDF

Author: I. Tsvankin

Publisher: Elsevier

Published: 2005-06-13

Total Pages: 472

ISBN-13: 9780080446189

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Following the breakthrough in the last decade in identifying the key parameters for time and depth imaging in anisotropic media and developing practical methodologies for estimating them from seismic data, Seismic Signatures and Analysis of Reflection Data in Anisotropic Media primarily focuses on the far reaching exploration benefits of anisotropic processing. This volume provides the first comprehensive description of reflection seismic signatures and processing methods in anisotropic media. It identifies the key parameters for time and depth imaging in transversely isotropic media and describes practical methodologies for estimating them from seismic data. Also, it contains a thorough discussion of the important issues of uniqueness and stability of seismic velocity analysis in the presence of anisotropy. The book contains a complete description of anisotropic imaging methods, from the theoretical background to algorithms to implementation issues. Numerous applications to synthetic and field data illustrate the improvements achieved by the anisotropic processing and the possibility of using the estimated anisotropic parameters in lithology discrimination. Focuses on the far reaching exploration benefits of anisotropic processing First comprehensive description of reflection seismic signatures and processing methods in anisotropic media

Understanding Seismic Anisotropy in Exploration and Exploitation, Second Edition

Understanding Seismic Anisotropy in Exploration and Exploitation, Second Edition PDF

Author: Leon Thomsen

Publisher: SEG Books

Published: 2014-10-01

Total Pages: 305

ISBN-13: 1560803266

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Understanding Seismic Anisotropy in Exploration and Exploitation (second edition) by Leon Thomsen is designed to show you how to recognize the effects of anisotropy in your data and to provide you with the intuitive concepts that you will need to analyze it. Since its original publication in 2002, seismic anisotropy has become a mainstream topic in exploration geophysics. With the emergence of the shale resource play, the issues of seismic anisotropy have become central, because all shales are seismically anisotropic, whether fractured or not. With the advent of wide-azimuth surveying, it has become apparent that most rocks are azimuthally anisotropic, with P-wave velocities and P-AVO gradients varying with source-receiver azimuth. What this means is that analysis of such data with narrow-azimuth algorithms and concepts will necessarily fail to get the most out of this expensively acquired data. The issues include not only seismic wave propagation, but also seismic rock physics. Isotropic concepts including velocity, Young’s modulus, and Poisson’s ratio have no place in the discussion of anisotropic rocks, unless qualified in some directional way (e.g., vertical Young’s modulus). Likewise, fluid substitution in anisotropic rocks, using the isotropic Biot/Gassmann formula, leads to formal errors, because the bulk modulus does not appear, in a natural way, within the anisotropic P-wave velocity. This updated edition is now current as of 2014.

3C Seismic and VSP: Converted waves and vector wavefield applications

3C Seismic and VSP: Converted waves and vector wavefield applications PDF

Author: James Gaiser

Publisher: SEG Books

Published: 2016-06-30

Total Pages: 637

ISBN-13: 1560803355

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3C seismic applications provide enhanced rock property characterization of the reservoir that can complement P-wave methods. Continued interest in converted P- to S-waves (PS-waves) and vertical seismic profiles (VSPs) has resulted in the steady development of advanced vector wavefield techniques. PS-wave images along with VSP data can be used to help P-wave interpretation of structure in gas obscured zones, of elastic and fluid properties for lithology discrimination from S-wave impedance and density inversion in unconventional reservoirs, and of fracture characterization and stress monitoring from S-wave birefringence (splitting) analysis. The book, which accompanies the 2016 SEG Distinguished Instructor Short Course, presents an overview of 3C seismic theory and practical application: from fundamentals of PS-waves and VSPs, through to acquisition and processing including interpretation techniques. The emphasis is on unique aspects of vector wavefields, anisotropy, and the important relationships that unify S-waves and P-waves. Various applications and case studies demonstrate image benefits from PS-waves, elastic properties and fluid discrimination from joint inversion of amplitude variations with offset/angle (AVO/A), and VSP methods for anisotropic velocity model building and improved reservoir imaging. The book will be of interest to geophysicists, geologists, and engineers, especially those involved with or considering the use of AVO/A inversion, fracture/stress characterization analyses, or interpretation in gas-obscured reservoirs.

Microseismic Monitoring

Microseismic Monitoring PDF

Author: Vladimir Grechka

Publisher: SEG Books

Published: 2017-09-01

Total Pages: 471

ISBN-13: 1560803479

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Over the past decade, microseismic monitoring, a technology developed for evaluating completions of wells drilled to produce hydrocarbons from unconventional reservoirs, has grown increasingly popular among oil and gas companies. Microseismic Monitoring, by Vladimir Grechka and Werner M. Heigl, discusses how to process microseismic data, what can and cannot be inferred from such data, and to what level of certainty this might be possible. The narrative of the book follows the passage of seismic waves: from a source triggered by hydraulic fracture stimulation, through hydrocarbon-bearing formations, towards motion sensors. The waves’ characteristics encode the location of their source and its focal mechanism. The analysis of various approaches to harvesting the source-related information from microseismic records has singled out the accuracy of the velocity model, fully accounting for the strong elastic anisotropy of hydraulically fractured shales, as the most critical ingredient for obtaining precise source locations and interpretable moment tensors. The ray theory complemented by its modern extensions, paraxial and Fréchet ray tracing, provides the only practical means available today for building such models. The book is written for geophysicists interested in learning and applying advanced microseismic data-processing techniques.