Abstract: Overview of Exploration Geophysics--Recent Breakthroughs and Challenging New Problems

Billy S. Flowers

Recent spectacular advances in geophysical technology are improving the explorationist's efficiency in his search for new hydrocarbon reserves. Each new development, however, usually points out some previously unrecognized shortcoming in geophysical techniques or the need for more precise geologic information in the interpretation of geophysical data.

For example, it is remarkable that hydrocarbons can be detected directly with "bright-spot" amplitude anomalies but the correct interpretation of these anomalies requires a more detailed knowledge of the stratigraphy than the geophysicist normally has; even the percentage of gas saturation is an important variable because low gas saturations lead to good amplitude anomalies.

Automatic migration has clarified structural configurations where the seismic-ray paths are simple, but many interesting areas have complex ray paths that are either focused or scattered by a series of "sonic lenses" of unknown geometry, velocity, and position. Correct interpretation of structures in this setting requires three-dimensional models of these parameters with some technique of model verification.

Surface arrays and common-depth-point stacking, now routine techniques, opened new areas to successful exploration by eliminating noise and multiples. Now, however, we find as our techniques improve that interesting areas still are obscured by more severe noises and by multiples beyond the reach of stacking.

Although the advances have been spectacular, they have exposed new problems, and possibly new opportunities, which are challenging indeed.

AAPG Search and Discovery Article #90971©1976 AAPG-SEPM Rocky Mountain Sections 25th Annual Meeting, Billings, Montana