Naturally fractured tight gas reservoir detection optimization. Quarterly report, July--September 1995

During the third quarter, processing continued at Western Geophysical. The processing was closely monitored by Palantir and Blackhawk Geosciences. Early in the processing Palantir determined that the original DMO velocities from the combined data volume were inadequate for performing the azimuthally split DMO. A series of DMO velocity scans were therefore run on each of the data sets and new velocities picked using two work stations simultaneously. This ensured uniform picking throughout the two volumes. DMO on the separated volumes and final migration demonstrated results that showed significantly clearer reflections than the total (all Azimuth) volume for certain intervals. A difference in the two velocity fields showed that the E-W data volume is consistently higher in velocity than the N-S data volume. This result would correspond to dominant, open E-W fractures at depth. This report also reviews the states of data acquisition and seismic source drilling and placement. It documents the shothole drilling design, layout, and detector placement