Ernest G Cook

US Patent:

45717109, Feb 18, 1986

Filed:

Aug 31, 1982

Appl. No.:

6/413428

Inventors:

Norman S. Neidell - Houston TX
Ernest E. Cook - Houston TX

International Classification:

G01V 130

US Classification:

367 38

Abstract:

This invention consists of producing a two-dimensional display from exploration seismic data designed to indicate zones of anomalous low velocity in the subsurface. Such zones may be indicative of porosity and the possible occurrence of hydrocarbons. They will be localized in terms of position along the seismic profile and in approximate zone of reflection arrival time. Data used in making the display are derived from both the CDP stacked seismic profile and corresponding velocity analyses used also to stack the data itself. Stacking velocity curves are plotted according to CDP location for each reflector designated by an interpreter to be of interest. These curves are overlain in pairs using calibration calculations and empirical criteria. Calibration helps smooth "noisy" values and compensates for velocity variations resulting from changes in separation or dip of the two reflectors from which the overlain velocity curves derive. In addition, it is presumed that the interval bracketed by each reflector pair taken in turn has uniform or only regional lateral variations of interval velocity--no local lateral variation is assumed.