Offset-dependent Reflectivity


Book Description

Recognizing the need for education and further research in AVO, the editors have compiled an all-encompassing treatment of this versatile technology. In addition to providing a general introduction to the subject and a review of the current state of the art, this unique volume provides useful reference materials and data plus original contributions at the leading edge of AVO technologies.













Reflection Coefficients and Azimuthal AVO Analysis in Anisotropic Media


Book Description

Observing offset-dependent seismic reflectivity has proven to be a valuable exploration tool for the direct detection of hydrocarbons. This monograph provides a comprehensive review of reflection coefficients and their approximations in isotropic media, followed by an in-depth discussion of reflection amplitudes in anisotropic media. No prior knowledge of seismic anisotropy is assumed, and considerable effort is spent to introduce wave propagation and medium parameterizations useful for surface seismic applications in the presence of anisotropy. The first anisotropic model discussed is transverse isotropy with a vertical axis of symmetry (VTI media), typically used to describe shale sequences. Then the study of VTI reflection coefficients is extended to transverse isotropy with a horizontal axis of symmetry (HTI) - the symmetry system that describes a system of parallel vertical cracks. Analysis of the "Shuey-type" approximate HTI P-wave reflection coefficient makes it possible to devise fracture-detection algorithms based on the inversion of azimuthal differences of the P-wave AVO gradient. The monograph also presents analysis of shear- and converted-wave reflection coefficients for HTI and orthorhombic models, discusses practical aspects of applying the azimuthal AVO analysis, and mentions promising recent results.




AVO


Book Description

AVO (SEG Investigations in Geophysics No. 16) by Satinder Chopra and John Castagna begins with a brief discussion on the basics of seismic-wave propagation as it relates to AVO, followed by a discussion of the rock-physics foundation for AVO analysis including the use of Gassmann’s equations and fluid substitution. Then, the early seismic observations and how they led to the birth of AVO analysis are presented. The various approximations for the Zoeppritz equations are examined, and the assumptions and limitations of each approximation are clearly identified. A section on the factors that affect seismic amplitudes and a discussion of the processing considerations important for AVO analysis are included. A subsequent section explores the various techniques used in AVO interpretation. Finally, topics including 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 are discussed. Equally helpful to new entrants into the field as well as to seasoned workers, AVO will provide readers with the most up-to-date knowledge on amplitude variation with offset.




Seismic Amplitude Interpretation


Book Description

Addresses the methodology of an amplitude interpretation and the subsequent benefits and limitations expected in rock-property settings. Included are relationships between rock properties and geophysical observations, practical problems, field examples, general rules, and case histories.




Petroleum Geoscience


Book Description

Petroleum geoscience comprises those geoscientific disciplines which are of greatest significance for the exploration and recovery of oil and gas. These include petroleum geology, of which sedimentary geology is the main foundation along with the contextual and modifying principles of regional, tectonic and structural geology. Additionally, biostratigraphy and micropalaeontology, organic geochemistry, and geophysical exploration and production techniques are all important tools for petroleum geoscientists in the 21st century. This comprehensive textbook present an overview of petroleum geoscience for geologists destined for the petroleum industry. It should also be useful for students interested in environmental geology, engineering geology and other aspects of sedimentary geology




Quantitative Seismic Interpretation


Book Description

Quantitative Seismic Interpretation demonstrates how rock physics can be applied to predict reservoir parameters, such as lithologies and pore fluids, from seismically derived attributes. The authors provide an integrated methodology and practical tools for quantitative interpretation, uncertainty assessment, and characterization of subsurface reservoirs using well-log and seismic data. They illustrate the advantages of these new methodologies, while providing advice about limitations of the methods and traditional pitfalls. This book is aimed at graduate students, academics and industry professionals working in the areas of petroleum geoscience and exploration seismology. It will also interest environmental geophysicists seeking a quantitative subsurface characterization from shallow seismic data. The book includes problem sets and a case-study, for which seismic and well-log data, and MATLAB® codes are provided on a website (http://www.cambridge.org/9780521151351). These resources will allow readers to gain a hands-on understanding of the methodologies.




Basic Theory in Reflection Seismology


Book Description

The material in this volume provides the basic theory necessary to understand the principles behind imaging the subsurface of the Earth using reflection and refraction seismology. For reflection seismology, the end product is a "record section" from a collection of "wiggly traces" that are recorded in the field from which information about the properties of subsurface structure and rock can be derived. For the most part, the principles of imaging are the same regardless of the depth to the target; the same mathematical background is necessary for targeting a shallow water table as for investigating the base of the earth's continental "crust" at a depth of 30-50 km.