ABSTRACT: Geologic Information and Seismic Data-How Much Do We Need?

NEIDELL, NORMAN, and ROSEMARY MULLIN , N.S. Neidell Associates, Houston, Texas

Much effort has gone into jointly using geologic information and seismic data. At the same time the variety of tasks addressed using such data has expanded quite significantly. We have moved from simple correlations for mapping structures to detailed analysis of reservoirs including defining flow units and parameter distributions. We are also building intricate velocity models for sophisticated methods of depth imagery.

It seems quite reasonable to seek great detail where there is an available database of geologic information to accompany seismic values. Such goals like optimizing reservoir performance or fully understanding stratigraphic systems make detail analysis clearly worthwhile. In fact, several geostatistical tools exist for addressing such projects and these are often coupled with advanced neural network approaches to enhance decision making.

For the case of velocity models to guide depth. imaging, the quest for detailed geologic information is often unrealistic in view of the stage when such tools are sometimes applied. Depth imaging is frequently used in preliminary studies to assist in basic understanding and mapping. At such times geologic information is sparse or even non-existent. Hence approaches requiring significant a priori geologic inputs are not likely to perform well.

We advocate balancing what we are attempting to accomplish with the degree of geologic information available. Methods that recognize such balance are illustrated. Recommendations are also given for attaining both reasonable and reliable results.

 

AAPG Search and Discovery Article #90908©2000 GCAGS, Houston, Texas