Abstract: Understanding Seismically Derived Impedance Logs

R. M. Cone, D. D. Thompson, J. E. Beitzel, J. L. Dees

The conversion of high-resolution reflection seismic data to an acoustic impedance log format (seismic logs) relieves the geophysical interpreter of much of the uncertainty involved in inferring subsurface geology from conventional seismic data. In producing these seismic logs particular emphasis is placed on their nonlinear relation to seismic traces. Although the fundamentals of seismically derived impedance logs are well known throughout the industry, the various factors affecting their quality have not been comprehensively demonstrated. These factors can be broadly separated into categories such as programmed gain, deconvolution phase and amplitude distortion, signal-to-noise ratio, and bandwidth. Through the use of an instructional array of synthetic and real example , the current capabilities and limitations of this process are demonstrated, thus illuminating some of the potential areas which could benefit most from further advances in data collection and processing technology. Under a favorable combination of the above factors, seismic logs provide the interpreter with otherwise obscure subsurface information.

AAPG Search and Discovery Article #90961©1978 AAPG Annual Convention and Exhibition, Oklahoma City, Oklahoma