Abstract Providing geophysicists with an in-depth understanding of the theoretical and applied background for the seismic diffraction method, “Classical and Modern Diffraction Theory” covers the history and foundations of the classical theory and the key elements of the modern diffraction theory. Chapters include an overview and a historical review of classical theory, a summary of the experimental results illustrating this theory, and key principles of the modern theory of diffraction; the early cornerstones of classical diffraction theory, starting from its inception in the 17th century and an extensive introduction to reprinted works of Grimaldi, Huygens, and Young; details of the classical theory of diffractions as developed in the 19th century and reprinted works of Fresnel, Green, Helmholtz, Kirchhoff, and Rayleigh; and the cornerstones of the modern theory including Keller’s geometrical theory of diffraction, boundary-layer theory, and super-resolution. Appendices on the Cornu spiral and Babinet’s principle are also included.

Abstract The use of diffraction imaging to complement the seismic reflection method is rapidly gaining momentum in the oil and gas industry. As the industry moves toward exploiting smaller and more complex conventional reservoirs and extensive new unconventional resource plays, the application of the seismic diffraction method to image sub-wavelength features such as small-scale faults, fractures and stratigraphic pinchouts is expected to increase dramatically over the next few years. “Seismic Diffraction” covers seismic diffraction theory, modeling, observation, and imaging. Papers and discussion include an overview of seismic diffractions, including classic papers which introduced the potential of diffraction phenomena in seismic processing; papers on the forward modeling of seismic diffractions, with an emphasis on the theoretical principles; papers which describe techniques for diffraction mathematical modeling as well as laboratory experiments for the physical modeling of diffractions; key papers dealing with the observation of seismic diffractions, in near-surface-, reservoir-, as well as crustal studies; and key papers on diffraction imaging.

Abstract Seismic Petrophysics in Quantitative Interpretation is written for oil and gas industry professionals and academicians who are concerned with the use of seismic data in petroleum exploration and production. In addition, it should prove useful toward thoughtful applications of those data by geotechnical engineers. Seismic interpretation can be made simple and robust by integrating rock-physics principles with the seismic and petrophysical attributes that bear on the properties of conventional reservoirs (thickness, net/gross, lithology, porosity, permeability, and satu-ration) and of unconventional reservoirs (thickness, lithology, organic richness, and thermal maturity). Practical solutions can be used to address existing interpretation problems in rock-physics-based AVO analysis and prestack seismic inversion in order to streamline the workflows in subsurface characterization.

Abstract 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.

Abstract We begin this book with a brief discussion on the basics of seismic-wave propagation as it relates to AVO, and we follow that with the rock-physics foundation for AVO analysis — including the use of Gassmann’s equations and fluid substitution. Then, as food for the inquisitive mind, we present briefly the early seismic observations and how they led to the birth of AVO analysis. Next, we examine the various approximations for the Zoeppritz equations and identify clearly the assumptions and limitations of each approximation. We follow that with a section on the factors that affect seismic amplitudes and a discussion of the processing considerations that are important for AVO analysis. A subsequent section explores the various techniques used in AVO interpretation. Finally, we discuss topics such as the influence of anisotropy in AVO analysis, the use of AVO inversion, estimation of uncertainty in AVO analysis, converted-wave AVO, and the future of the AVO method.

Abstract “Modeling of seismic wave propagation is a core component in almost every aspect of exploration seismology, ranging from survey design methods to imaging and inversion algorithms. The last time SEG published a reprint volume on numerical modeling was in 1990. Since then, the last two decades has seen a step change in the application and use of Â"full wave equationÂ" modeling methods enabled by the tremendous increase in available computational power. Full waveform inversion, reverse time migration and 3D elastic finitedifference synthetic data generation are examples of modeling applications that are currently having a fundamental impact on our business. In Numerical Modeling of Seismic Wave Propagation: Gridded Two-way Wave-equation Methods, readers will find many of the wellknown and referenced papers from the exploration seismic community as well as some of the key papers that have impacted other fields of seismology. Because the modeling literature is vast, we have limited the scope of the reprint volume to papers over the last two decades on modeling methods based on the full wave equation. The reprint volume will be of particular interest to researchers and practitioners interested in modeling methods and their applications. The searchable CD includes the 114-page book of abstracts and the full papers.”

Abstract During the past decade, a radical change has taken place in the way seismic processing delivers a subsurface image. Previously, we employed a purely linear processing sequence, moving from data preconditioning to velocity estimation and culminating in a single time-migrated 3D image. The work of the contractor’s data processor was separate and distinct from that of the client’s interpreter.

Abstract In this chapter, we give a brief synopsis of each of the classic papers referred to in this collection. Where relevant, we reproduce the basic equations, recast in modern notation. Supporting works also are referred to. They are listed in the “General References” section. Table 1 is a quick outline of the key contributions of each paper reprinted in this book. Robert Hooke, “Potentia Restitutiva, or Spring” (Oxford, 1678) The article by Robert Hooke, “Potentia Restitutiva, or Spring,” contains the statement of the proportional relation between stress and strain universally referred to as Hooke’s law. Although the English language has evolved somewhat since 1678, the article does not require translation. Hooke describes a variety of experiments, accompanied by illustrations, confirming the stress/strain relation over a wide range of applied loads. He emphasizes the great generality of his results. Based on his experimental work from 1660 onward, Hooke first published his law in 1676 in the form of an anagram in Latin, which he later revealed to be “ut tensio sic vis.” Roughly translated, this means “as the force, so is the displacement” (Love, 1911; Boyce and DiPrima, 1976). In his treatise, Hooke examined the behavior of springs, so his first casting of the equations dealt with the restoring force on a spring, for a given displacement:

Abstract In the past decade, 3D reflection seismology has replaced 2D seismology almost entirely in the seismic industry. Recording 3D surveys has become the norm instead of the exception. The application of 2D seismology is limited mostly to reconnaissance surveys or to locations where recording 3D data is still prohibitively expensive, such as in rough mountains and wild forests. However, academic research and teaching have struggled to keep up with the 3D revolution. As a consequence of this tardiness, no books are available that introduce the theory of seismic imaging from the 3D perspective. This book is aimed at filling the gap. Seismic processing of 3D data is inherently different from 2D processing. The differences begin with data acquisition: 3D data geometries are considerably more irregular than 2D geometries. Furthermore, 3D acquisition geometries are never complete because sources and receivers are never laid out in dense areal arrays covering the surface above the target. These fundamental differences, along with the increased dimensionality of the problem, strongly influence the methods applied to process, visualize, and interpret the final images. Most 3D imaging methods and algorithms cannot be derived from their 2D equivalent by merely adding a couple of dimensions to the 2D equations. This book introduces seismic imaging from the 3D perspective, starting from a 3D earth model. However, because the reader is likely to be familiar with 2D processing methods, I discuss the connections between 3D algorithms and the corresponding 2D algorithms whenever useful. The book covers all the important aspects of 3D imaging. It links the migration methods with data acquisition and velocity estimation, because they are inextricably intertwined in practice. Data geometries strongly influence the choice of 3D imaging methods. At the beginning of the book, I present the most common acquisition geometries, and I continue to discuss the relationships between imaging methods and acquisition geometries throughout the text. The imaging algorithms are introduced assuming regular and adequate sampling. However, Chapters 8 and 9 explicitly discuss the problems and solutions related to irregular and inadequate spatial sampling of the data. Velocity estimation is an integral component of the imaging process. On one hand, we need to provide a good velocity function to the migration process to create a good image. On the other hand, velocity is estimated in complex areas by iterative migration and velocity updating. Migration methods are presented first in the book because they provide the basic understanding necessary to discuss the velocity updating process. Seismic-imaging algorithms can be divided into two broad categories, integral methods (e.g., Kirchhoff methods) and wavefield-continuation methods. Integral methods can be described by simple geometric objects such as rays and summation surfaces. Thus, they are understood more easily by intuition than wavefield-continuation methods are. My introduction of the basic principles of 3D imaging exploits the didactic advantages of integral methods. However, wavefield-continuation methods can yield more accurate images of complex subsurface structures. This book introduces wavefield-continuation imaging methods by leveraging the intuitive understanding gained during the study of integral methods. Wavefield-continuation methods are the subject of my ongoing research and that of my graduate students. Therefore, the wavefield-continuation methods described are more advanced, although less well established, than the corresponding integral methods. Seismic-imaging technology is data driven, and the book contains many examples of applications. The examples illustrate the rationale of the methods and expose their strengths and weaknesses. The data examples are drawn both from real data sets and from a realistic synthetic data set, the SEG-EAGE salt data set, which is distributed freely and used widely in the geophysical community. For the reader's convenience, a subset of this data set (known as C3 narrow-azimuth) is contained in the DVD included with this book. Appendix 2 briefly describes this data set. The software needed to produce many examples also will be distributed freely over the Internet. A reader with the necessary computer equipment (a powerful Unix workstation) and the patience to wait for weeks-long runs could reproduce the images obtained from the SEG-EAGE salt data set. Appendix A describes the foundations of SEPlib3d, the main software package needed to generate most of the results shown in this text. The book starts from the introduction of the basic concepts and methods in 3D seismic imaging. To follow the first part of the book, the reader is expected to have only an elementary understanding of 2D seismic methods. The book thus can be used for teaching a first-level graduate class as well as a short course for professionals. The second part of the book covers more complex topics and recent research advances. This material can be used in an advanced graduate class in seismic imaging. To facilitate the teaching of the material in this book, the attached DVD includes a document in PDF format that has been formatted specifically to be projected electronically during a lecture. All the figures in this electronic document can be animated by clicking on a button in the figure caption. Several of these figures are movies that provide a more cogent illustration of the concepts described in the text. All figures are included on the attached DVD as GIF files.

Abstract This first chapter sets the stage for the later technical development of Dr. Whit’s career in applied seismics. Experiments, f’wst at the Acoustics Laboratory of the Massachusetts Institute of Technology and later at Mobil Oil and Marathon Oil, provided insight into the general problems of impedance measurements, transduction, filtering, and attenuation. These papers also serve as a bridge to show geophysicists how theft own experiments in seismology naturally interface with (indeed, arose out of) the larger world of sound measurements in air and water. These experiments demonstrate the power of geometrically constrained experiments to allow verification of approximate (and in some cases, exact) theories of sound.

Abstract “This text presents explanations and definitions of many terms currently and previously used in well logging.”