Geophysical References – serie

The fourth edition of SEG’s best seller is a valuable, comprehensive reference that is a must for every geophysicist, geologist, explorationist, engineer, energy adviser, economist, editor, and student involved in the field. Hundreds of terms have been added since publication of the third edition in 1991, reflecting rapid evolution of the science, especially in the areas of engineering and production problems, 3D (including multicomponent) acquisition and processing, visualization, S- and converted waves, interpretation, anisotropy, AVO, geostatistics, geohazards, neural networks, tomography, downhole measurements, horizontal drilling, and deepwater work. Definitions of hundreds of other terms have been updated. The dictionary’s title has been modified slightly to reflect growth in application of geophysical methods, with the word Applied replacing the word Exploration. The dictionary includes a guide to pronunciation and a list of reference figures and tables. A CD containing the dictionary in searchable PDF format also is included.

Because most sedimentary rocks encountered in oil and gas exploration are effectively anisotropic, it is imperative to properly estimate seismic anisotropy and incorporate it into data-processing and imaging algorithms. Seismology of Azimuthally Anisotropic Media and Seismic Fracture Characterization (SEG Geophysical References Series No. 17) presents a systematic analysis of seismic signatures for azimuthally anisotropic media and describes anisotropic inversion/processing methods for wide-azimuth reflection data and VSP (vertical seismic profiling) surveys. The main focus is on kinematic parameter-estimation techniques operating with P-waves as well as with the combination of PP and PS (mode-converted) data. The part devoted to prestack amplitudes includes azimuthal AVO (amplitude variation with offset) analysis and a concise treatment of attenuation coefficients, which are highly sensitive to the presence of anisotropy. Discussion of fracture characterization is based on modern effective media theories and illustrates both the potential and limitations of seismic methods. Field-data examples highlight the improvements achieved by accounting for anisotropy in seismic processing, imaging, and fracture detection.

Filling the gap between theoretical literature and the routine activities of geophysicists in the oil industry, The Seismic Signal and Its Meaning is a translation of the second edition of Análise do Sinal Sísmico, published in Portuguese by Sociedade Brasileira de Geofísica (SBGf). For those performing acquisition, processing, and/or interpretation, this book will aid an understanding of how practical problems may have important links to seismic data analysis theory. With an emphasis on providing an objective description of the physical and mathematical aspects that support these links, the rules necessary for robust reservoir characterization are presented. With an extensive development of Gassmann’s (and Biot) theory and its relevance, the book concentrates on phase and amplitude distortions to the seismic signal, the physical processes that it undergoes, and the interpretation methods to recover rock physics properties. Capturing 30 years of teaching and improvement as a part of Petrobras internal courses, the book is a modern treatment, reflecting the many advances that have occurred in geophysics. The book serves as both a text and a reference.

Over the past decade, microseismic monitoring, a technology used to evaluate the 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, presents a thorough description of how to process microseismic data and the underlying theory, of what can and cannot be inferred, and to what level of certainty. The layout of the book follows the passage of a seismic wave – from a source triggered by hydraulic stimulation, through hydrocarbon-bearing formations, towards motion sensors. The analysis of various approaches to harvesting the source-related information from microseismic records has singled out the accuracy of the velocity model as the most critical ingredient for the quality of microseismic deliverables and our understanding of the information contained in those. An accurate velocity model, fully accounting for the strong elastic anisotropy of hydraulically fractured shales, is a prerequisite for obtaining precise event hypocenters and interpretable seismic moment tensors. The ray theory complemented by its modern extensions, the paraxial ray tracing and Frechet ray tracing, provides the only practical means available today for building such models. This book was written for geophysicists interested in learning advanced microseismic data-processing techniques.