Seismic Exploration Methods

ISBN-13: 9789401163996 / Angielski / Miękka / 2012 / 296 str.

Ray L. Sengbush

Opis

This book describes the seismic methods used in geophys ical exploration for oil and gas in a comprehensive, non rigorous, mathematical manner. I have used it and its predecessors as a manual for short courses in seismic methods, and it has been extensively revised time and again to include the latest advances in our truly remark able science. I once called it, "Advanced Seismic Inter pretation," but the geophysicists who attended the courses always wondered when I was going to start dis cussing interpretation. They discovered at the end that I never did discuss interpretation as they knew it. No men tion was made of reflection picking, posting times, map ping, contouring, and things they already knew perfectly well. Instead, I discussed Fourier transforms, sampling theory, impulse responses, distortion operators, Wiener filters, noise in f-k space, velocity spectra, wave-equation migration, and direct detection of hydrocarbons as each of these topics appeared on the seismic scene. I wanted the geophysicists to think beyond the routine ofinterpre tation, to develop a better understanding of why seismic sections look as they do, to have a better feel for what digital processing is doing, for good or evil, to the seismic data. I attempted to stretch their minds. Whitehead said it best: "A mind once stretched by a new idea can never shrink to its former dimension. " May this book be a suc cessful mind-stretcher. R. L.

Spis treści

Chapters 1. Introduction to Seismic Methods.- Reflection Method.- Refraction Method.- Summary.- Chapters 2. Seismic Wave Propagation.- Elasticity.- Elastic Waves.- Raypath Theory.- Diffractions.- Summary.- Chapters 3. Seismic Signatures.- Land Sources.- Marine Sources.- Shear Sources.- Spherical Spreading.- Attenuation.- Summary.- Chapters 4. Analysis and Suppression of Seismic Noise.- Suppression of Random Noise.- Horizontally Traveling Noise.- Coherent Noise Analysis.- Patterns: Space-Domain Filters.- Pattern Design.- Velocity Filters.- Summary.- Chapters 5. The Seismic Signal Process.- The Linear Filter Model of the Seismic Reflection Process.- Simple Acoustic Impedance Functions.- Correspondence Between Depth and Time.- Comparing Synthetics with Field Records.- Summary.- Chapters 6. Multiple Reflections.- Ghosts and Reverberations.- Multiple Generation Within the Seismic Section.- Multiple Suppression.- Summary.- Chapters 7. Distortion Operators and Deconvolution.- Distortion Operators and Their Deterministic Inverse Operators.- Wiener Inverse Filter.- Wiener Processing of Play Data.- Wiener Processing of Field Data.- Wiener Deconvolution and Nonminimum-Phase Data.- Other Types of Deconvolution.- Summary.- Chapters 8. Velocity Estimation.- Shooting a Well.- Continuous Velocity Logs.- Dix’s Expanding Spread Technique.- Velocity Spectra Obtained in Conjunction with Horizontal Stacking.- Applications of Velocity Spectra in Predicting Lithology.- Summary.- Chapters 9. Migration Techniques.- Migration by the Hagedoorn Method.- Migration by Summation Methods.- Migration by Finite Differences.- Migration Using Fourier Methods.- Three-Dimensional Migration.- Summary.- Chapters 10. Direct Detection of Hydrocarbons on Seismic Data.- Direct Detection Techniques.- Theoretical Velocity and Density Calculations.- Model Studies.- Case Histories.- Information-Preserving Processing.- Summary.- Appendixes.- A. Transform Theory.- Fourier Transforms.- Laplace Transforms.- Z-Transforms.- Hilbert Transforms.- B. Linear System Theory.- Linear Systems.- Impulse Response.- Filtering in the Time Domain.- Types of Linear Systems.- Analog and Digital Filters.- C. Sampling Theory.- Time-Domain Sampling.- Aliasing: Sampling Is Not Filtering.- Frequency-Domain Sampling.- Time-Limited and Band-Limited Functions.- Mathematical Operations with Time Series.- D. Random Processes.- Theory of Probability.- Random Variables.- Ensemble Averages.- Time Averages.- Spectral Considerations.- Estimation of Power Spectrum.- Random Inputs to Linear, Time-Invariant Systems.- E. Mathematics of Wave Propagation.- Stress and Strain.- Hooke’s Law.- Wave Equation.- Boundary Conditions: Plane Waves with Normal Incidence.- Energy Relations.- References.