Velocities in Reflection Seismology

✍ Scribed by Jean-Pierre Cordier (auth.)

• Publisher: Springer Netherlands
• Year: 1985
• Tongue: English
• Leaves: 213
• Series: Seismology and Exploration Geophysics 3
• Edition: 1
• Category: Library

✦ Synopsis

Although considera bIe efforts are now being made to find new sources of energy, alI the experts are agreed that hydrocarbons will have to provide the greater part of our energy needs for a generation ahead. Exploration for and production of hydrocarbons therefore pose a serious problem for our future, as much for the quantitative satisfaction of our requirements as for our search for self-sufficiency in energy. As a direct result of improvements in technology throughout the world, geophysics has progressively enlarged its field of influence in the realms of exploration and production. But amongst the various geophysical methods available, seismic reflection has gradually become accepted as the basic tool of the oiI prospector. Reflection seismology has reached and consolidated this position because it has shown itself to be capable of adapting to the increasing complexity of the requirements of exploration. Initially directed towards geometric mapping of the sub-surface, it became the means of detection of structural traps in geotectonically quiescent regions, and thereafter in increasingly complex surroundings. It has enabled us to clothe the structural framework with a lithology, initially approximate, but becoming more and more precise, assisting the explorer to locate stratigraphic traps. Further developments enable us under favourable circumstances to estimate the quality of the deposits and to detect the presence of fluids and of their interfaces; it then becomes an unrivalled tool for the producer, both in the development of deposits and in the application of enhanced recovery methods.

✦ Table of Contents

Front Matter....Pages i-xiii
Basic Ideas on the Propagation of Seismic Waves....Pages 1-5
General Considerations on the Recording of Seismic Waves in Prospecting for Oil....Pages 6-13
Velocity of Seismic Waves, Relationships with the Theory of Elasticity, Variation Factors....Pages 14-24
Calculation of Travel Times of Seismic Signals, Definition of ΔT....Pages 25-35
Measurement of Velocities in Boreholes. Sonic Logs. Seismic Surveys of Boreholes. Pseudo Velocity Logs. Transformation of Resistivity Logs to Velocity Logs....Pages 36-46
Velocities in Seismic Reflection. Definitions. Principles of Velocity Analysis....Pages 47-58
Relationships between Stacking Velocities and Root Mean Square Velocities....Pages 59-70
Relationships between Root Mean Square Velocities, Average Velocities, and Coefficients of Heterogeneity....Pages 71-84
Investigation of the Influence of Dip on Velocity Analyses....Pages 85-100
Calculation of Interval Velocities....Pages 101-114
Velocity Analysis. Principles. Examples....Pages 115-125
Choice of Parameters in Velocity Analysis....Pages 126-128
Other Presentations of Velocity Analyses. Analyses along Horizons. Constant Velocity Stacks. Rapid Determination of Interval Velocities: G.S.I. (Geophysical Service Inc.) Graphical Method....Pages 129-134
Interpretation and Utilisation of Velocity Analyses. Accuracy Required and Causes of Inaccuracy. Advice on Positioning and Interpretation of Velocity Analyses....Pages 135-154
Influence of the “Velocity” Parameter on the Process of Migration of Seismic Sections....Pages 155-167
Studies of Velocities in Sand-Shale Series....Pages 168-197
Back Matter....Pages 199-203

✦ Subjects

Economic Geology; Geophysics/Geodesy