Publications

The projected goals of geophysical exploration have been shifting steadily toward more quantitative and sophisticated geologic estimates. Where a decade ago we might have been satisfied to map the gross structure in the zone of interest, we now hope to determine reliable estimates of such rock parameters as velocity, density, and, ultimately, hydrocarbon content.The trend toward quantitative lithologic measurement is well expressed in the onedimensional case by the process of converting a seismic trace into a simulated borehole acoustic log. Coupled with the structural objectives, the ideal geophysical output data, ready for interpretation, would then consist of an areal array of such logs.To extract such precise geometric and lithologic information from surface geophysical methods places heavy demands on both the recording and processing technology. The temporal and spatial resolution required now and in the future would have been considered unattainable a few years ago. Finer sampling in time and space, simultaneous individual recording and real-time processing of hundreds of channels, source and receiver improvements, three-dimensional recording geometry, shear wave sources and receivers, are but a few of the features of the current recording trend.Processing has kept pace, aided by a trend toward industry-academic research and development projects. Developments include everexpanding wave equation processing, wavelet processing, coherency enhancement, attenuation analysis, multi-parameter color displays, forward and inverse modeling, and interpretive processing (seismic signature analysis, ",geologic", computer contouring, lithologic mapping).As these high resolution trends continue, the explorationist's confidence in the geophysical tool as a quantitative hydrocarbon predictor grows accordingly.