ABSTRACT: Resolving Reservoir Complexes Below Seismic Resolution Using Color Seismic Displays and Model Studies

Norman S. Neidell, Thomas A. Smith

There are instances when hydrocarbon reservoirs are relatively thin and separated vertically, thus appearing as a thin-bed complex that cannot be properly resolved by normal seismic techniques. The properties of the thin units even including hydrocarbon presence, can vary greatly laterally and have important impact on both the exploration and production potential of such accumulations.

We show that although seismic amplitude, frequency, and other gross measures, in fact, do respond to the detailed geologic structure of the complex, that the waveform shape itself is the most important diagnostic factor. Shape changes unfortunately cannot be perceived on normal seismic displays even when the individual waveforms are magnified greatly.

In this work we show via model studies and field data that the use of color displays with greatly enhanced visual dynamic range enables us to work effectively below the normally understood resolution limits of seismic data to characterize the thin bed complex and their reservoir properties.

No new theoretical ground is broken here. We are simply taking advantage of the expanded visual dynamic range of color seismic presentations to reveal the more subtle information content of the data. Model studies enable us to test the most likely geologic configurations and recognize their signatures as geometric patterns of color contrasts directly on the original displays.

This study gives further evidence to the notion that even for conventional seismic data, our present techniques do not fully use the information content.

AAPG Search and Discovery Article #91003©1990 AAPG Annual Convention, San Francisco, California, June 3-6, 1990