Seismic Amplitude Interpretation

With interest in reducing exploration risk, this interactive presentation addresses the methodology of amplitude interpretation and benefits and limitations expected in rock-property settings. Included are relationships between rock properties and geophysical observations, practical problems, field examples, general rules, and case histories.

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This is a computer-based, interactive presentation of the 2001 SEG/EAGE Distinguished Instructor Short Course, "Seismic Amplitude Interpretation." Catalog #224A is the accompanying DISC book. During the last 30 years, seismic interpreters routinely have applied bright-spot and AVO technology for recognizing prospects and predicting lithology. New amplitude attributes were added to this technology as new exploration problems were defined. R & D continues in the field of amplitude interpretation, especially when E & P costs escalate as more severe environments are explored, such as ultradeepwater plays. With the high interest in reducing exploration risk, this course addresses the methodology of an amplitude interpretation and the subsequent benefits and limitations that one can expect in various rock-property settings. This book begins with a review of the relationships between rock properties and geophysical observations. Practical problems illustrate the assumptions and limitations of commonly used empirical transforms, and procedures for conducting and verifying fluid-substitution techniques are presented. The book identifies components of the seismic response best suited for differentiating pore fluid from lithologic effects. Field examples emphasize what combination of seismic signatures should be expected for different rock-property environments. To help select the best seismic attribute for calibrating amplitude to rock properties, general rules are provided for predicting AVO responses and interpreting lithology from observed responses. A case history also is provided. The last part examines the numerous amplitude attributes that can be extracted from seismic data to quantify an interpretation. Benefits and limitations of these attributes in soft- to hard-rock environments are discussed with model data and in case histories.