Since the introduction in the early 1960s of digital recordings and processing of seismic data, the effectiveness of the seismic method as a petroleum exploration tool has improved substantially by providing better solutions to many problems such as water reverberations and resolution of discrete reflectors. Thus far, the primary emphasis has been on the development and application of new signal-processing techniques through the utilization of communication-theory concepts. With the development of large rapid-access bulk-storage devices and high-resolution on-line display capabilities, the scope of computer processing can be enlarged to include interpretation and the integration of geophysical and geological data.

Continuous interval-velocity information, with an estimated associated error, can now be extracted from seismic data on a routine basis. Examples from field tests show that, in favorable cases, lateral variations in interval velocity of the order of 1% may be detected. In addition to obtaining a major increase in the accuracy of structural information, continuous velocity data provide a means for detecting lithologic and stratigraphic variations. This capability coupled with a means for extracting and displaying quantitative information about reflector amplitude and waveform provides new possibilities for stratigraphic-trap exploration.

Examples from the Gulf of Mexico show how the computer may be utilized to obtain an interpretation of a grid of seismic data with the assistance of an interpreter to make difficult interpretation decisions and to correct the inevitable errors which can occur in the processing sequence. The capability of the computer to deal with and migrate all the relevant data in three dimensions will lead to a more accurate and complete three-dimensional model of the subsurface from seismic data. As this capability is realized, it will become useful to record seismic data on a tighter grid than is done with current practices.

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