Kirjahaku

This book is about exploration for oil and gas and focuses particularly on seismic exploration in the hunt for hydrocarbons. The first part, "The Hunt for Hydrocarbons," gives general background informa­ tion, with an introductory chapter on the beginnings of the oil business followed by three chapters that in­ clude elements of petroleum geology, geophysical methods, and drilling and logging. The second part, "Seismic Exploration for Hydrocarbons," consists of two chapters that describe rudiments of the seismic method and velocity measurements; two chapters dis­ cussing theory based on wave propagation and the convolutional model; and a chapter devoted to each of the three phases of seismic exploration: acquisi­ tion, processing, and interpretation. I have concen­ trated on seismic exploration because most of the oil and gas that has been found has been located by this method, and it is the only method that has the poten­ tial for the increased precision needed in what Hal­ bouty (1982) calls "the deliberate search for the subtle trap. " In contrast to elementary and introductory books that present the seismic method superficially and qualitatively, this book develops the method quanti­ tatively, using only elementary mathematics (algebra and trigonometry), so that readers should be able to do things afterwards that they couldn't do before, and thereby get a deeper appreciation of the business of hunting for hydrocarbons. The book also probes into some sophisticated topics that wouldn't be mentioned IX x use in short courses at a variety of levels.

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.