A quasi-Monte Carlo approach to efficient 3-D migration: Field data test

The quasi-Monte Carlo migration algorithm is applied to a 3-D seismic data set from West Texas. The field data were finely sampled at approximately 220-ft (67-m) intervals in the in-line direction but were sampled coarsely at approximately 1320-ft (402-m) intervals in the cross-line direction. The traces at the quasi-Monte Carlo points were obtained by an interpolation of the regularly sampled traces. The subsampled traces at the quasi-Monte Carlo points were migrated, and the resulting images were compared to those obtained by migrating both regular and uniform grids of traces. Results show that, consistent with theory, the quasi-Monte Carlo migration images contain fewer migration aliasing artifacts than the regular or uniform grid images. For these data, quasi-Monte Carlo migration apparently requires fewer than half the number of the traces needed by regular-grid or uniform-grid migration to give images of comparable quality. These results agree with related migration tests on synthetic data computed for point scatterer models. Our results suggest that better migration images might result from data recorded on a coarse quasi-random grid compared to regular or uniform coarse grids.