Seismic Refraction Prospecting

This volume is a compilation of the newer techniques of refraction seismic surveying. It contains a series of articles written principally by members of SEG who are specialist in refraction techniques. The volume contains only new materials with a bibliography of references to other refraction materials available. The majority of the papers are of a "technique type" which describe some particular interpretation technique that may be used for better interpretation of special refraction data.

The papers in this volume describe various techniques for separating out special raypath solutions and making approximations that give us a structural geologic picture from the study of these approximations or specializations.

Basic Seismic Refraction Survey and Data Interpretation Techniques This book is written to impart knowledge on seismic refraction method, which covers data acquisition, processing and interpretation techniques. The discussion in this book is about seismic waves and their characteristics, theory of seismic refraction and field procedures. Examples of seismic refraction data and simple calculation are also provided to enable readers to better visualize and aid their understanding on the seismic refraction method. Rosli Saad is currently a lecturer at School of Physics, Universiti Sains Malaysia, Pulau Pinang with 30 years of experience in geophysics. His expertises is in the areas of Ground Penetrating Radar (GPR), gravity, magnetic, seismic and electrical methods. His main research is in engineering and environmental studies. He has published three research book chapters, four research books and more than 250 journal papers. Recently, he was appointed as head of geophysics section at the Centre of Tropical Geoengineering (GEOTROPIK), Universiti Teknologi Malaysia.

OF EXPLORATION METHODS COMMONLY USED: Library studies -- Surface geology -- Core drilling -- Aerial mapping -- Magnetomenter surveys -- Gravity surveys -- Seismic reflection exploration -- Seismic refraction exploration -- Wildcat drilling -- Miscellaneous methods -- SUMMARY OF SEISMIC METHODS COMMONLY USED: Seismic dip work -- Continuous profiling -- The reflection correlation method -- Reflection strike dip surveys -- Refraction surveys -- Reconnaissance surveys -- Detailed surveys -- ROUTINE SEISMIC CREW OPERATION COST REDUCTION: Equipment and personnel overhead -- Geared and ungeared operations -- Functional analysis of geared operations -- Maximum recording efficiency -- Miscellaneous field efficiency considerations -- Office routine -- Danger of losing sight of the purpose of the geared work -- EFFICIENT EXPLORATION PROGRAMS: Synthesis organization of exploration programs -- What is exploration information -- Probability of finding oil -- Expected efficiency -- An analogy -- The place of seismic prospecting in the overall picture -- BASIC TECHNICAL TOOLS: Terminology and use of figures -- Pulse fronts rays -- Snells law -- Apparent velocity -- DATUM CORRECTIONS: Corrections based on short offset geophone locations -- Corrections based on long or medium offset geophone data -- Up hole shooting for weathering velocity -- Calculations based on weathering shots -- Differential weathering correction -- Corrections for point plotting -- Corrections to a deeper datum -- Interrelation of methods preferences.

In the geophysics of oil exploration and reservoir studies, the surface seismic method is the most commonly used method to obtain a subsurface model in 2 or 3 dimensions. This method plays an increasingly important role in soil investigations for geotechnical, hydrogeological and site characterization studies regarding seismic hazard issues. The goal of this book is to provide a practical guide, using examples from the field, to the application of seismic methods to surface imaging. After reviewing the current state of knowledge in seismic wave propagation, refraction and reflection seismic methods, the book aims to describe how seismic tomography and fullwave form inversion methods can be used to obtain seismic images of the subsurface. Through various synthetic and field examples, the book highlights the benefit of combining different sets of data: refracted waves with reflected waves, and body waves with surface waves. With field data targeting shallow structures, it shows how more accurate geophysical models can be obtained by using the proposed hybrid methods. Finally, it shows how the integration of seismic data (3D survey and VSP), logging data (acoustic logging) and core measurements, combined with a succession of specific and advanced processing techniques, enables the development of a 3D high resolution geological model in depth. In addition to these examples, the authors provide readers with guidelines to carry out these operations, in terms of acquisition, as well as processing and interpretation. In each chapter, the reader will find theoretical concepts, practical rules and, above all, actual application examples. For this reason, the book can be used as a text to accompany course lectures or continuing education seminars. This book aims to promote the exchange of information among geologists, geophysicists, and engineers in geotechnical fields.