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Seismic amplitude inversion in reflection tomography [electronic resource]

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Time-frequency analysis of seismic signals

"Time-frequency analysis is an important physics-driven technology in seismic data processing for the interpretation of the geological properties of natural fuels such as coal or gas. The technology can be applied not only for assistance in exploring natural mineral resources, but also for environmental monitoring, such as natural hazards, and in environmental protection."--A practical and insightful discussion of time-frequency analysis methods and technologies Time-frequency analysis of seismic signals aims to reveal the local properties of nonstationary signals. The local properties, such as time-period, frequency, and spectral content, vary with time, and the time of a seismic signal is a proxy of geologic depth. Therefore, the time-frequency spectrum is composed of the frequency spectra that are generated by using the classic Fourier transform at different time positions. Different time-frequency analysis methods are distinguished in the construction of the local kernel prior to using the Fourier transform. Based on the difference in constructing the Fourier transform kernel, this book categorises time-frequency analysis methods into two groups: Gabor transform-type methods and energy density distribution methods. This book systematically presents time-frequency analysis methods, including technologies which have not been previously discussed in print or in which the author has been instrumental in developing. In the presentation of each method, the fundamental theory and mathematical concepts are summarised, with an emphasis on the engineering aspects. This book also provides a practical guide to geophysicists who attempt to generate geophysically meaningful time-frequency spectra, who attempt to process seismic data with time-dependent operations for the fidelity of nonstationary signals, and who attempt to exploit the time-frequency space seismic attributes for quantitative characterisation of hydrocarbon reservoirs.

Online Wiley Online Library

Seismic inversion : theory and applications

Seismic inversion aims to reconstruct a quantitative model of the Earth subsurface, by solving an inverse problem based on seismic measurements. There are at least three fundamental issues to be solved simultaneously: non-linearity, non-uniqueness, and instability. This book covers the basic theory and techniques used in seismic inversion, corresponding to these three issues, emphasising the physical interpretation of theoretical concepts and practical solutions. This book is written for master and doctoral students who need to understand the mathematical tools and the engineering aspects of the inverse problem needed to obtain geophysically meaningful solutions. Building on the basic theory of linear inverse problems, the methodologies of seismic inversion are explained in detail, including ray-impedance inversion and waveform tomography etc. The application methodologies are categorised into convolutional and wave-equation based groups. This systematic presentation simplifies the subject and enables an in-depth understanding of seismic inversion. This book also provides a practical guide to reservoir geophysicists who are attempting quantitative reservoir characterisation based on seismic data. Philosophically, the seismic inverse problem allows for a range of possible solutions, but the techniques described herein enable geophysicists to exclude models that cannot satisfy the available data. This book summarises the author s extensive experience in both industry and academia and includes innovative techniques not previously published.

Online Wiley Online Library