|
چکیده
|
The Common-Reflection-Surface (CRS) stack method parameterizes and stacks seismic reflection events in a generalized stacking velocity analysis. It considers a discrete number of events contributing to a given stack sample such that conflicting dip situations can be handled. The reliable detection of such situations is difficult and missed contributions to the stacked section cause artifacts in a subsequent poststack migration. This is deleterious for complex data where prestack migration is no viable option due to its demands on velocity model accuracy, such that we might have to rely on poststack migration. As an alternative, the conflicting dip problem has been addressed by explicitly considering a virtually continuous range of dips with a simplified stacking operator in a process termed Common-Diffraction-Surface (CDS) stack. In analogy to the CRS stack, the CDS stack has been implemented and successfully applied in a data-driven manner based on coherence analysis in the prestack data. In view of the computational costs, we present a more efficient model-based approach to the CDS stack designed to generate stack sections optimized to image discontinuities by poststack migration. This approach only requires a smooth macro-velocity model of minor accuracy. We present our results for the synthetic Sigsbee 2A data and compare them to the results of CRS stack and datadriven CDS stack.
|