Parallel 3D prestack depth migration using recursive Kirchhoff extrapolation
Hugh D. Geiger, Gary F. Margrave, Darren S. Foltinek, J. Marc Langlois
We have designed and implemented a parallel 3D prestack depth migration algorithm based on recursive Kirchhoff extrapolators. Recursive Kirchhoff wavefield extrapolation in the frequency-space domain allows us to use the Weyl formulation, which should give better estimates of the phase than either the GPSPI (generalized phase shift plus interpolation) or NSPS (non-stationary phase shift) formulations, and hence reconstruct the extrapolated wavefield with greater accuracy. The algorithm has been coded for single- and multiple-node processing in both MATLAB and C. Simple synthetics tests have greatly accelerated the testing and debugging phase of the software development. This project lays the foundation for the POTSI research-friendly framework for parallel seismic processing and imaging, which will allow us to efficiently investigate a variety of compute-intensive problems in seismic processing and imaging. Key features of the research framework are: full integration with existing software including the CREWES MATLAB seismic toolbox, Seismic Unix, USP, and ProMAX; concurrent design and coding in MATLAB and C/FORTRAN; and semi-automated archiving. Research plans for the upcoming year include depth migration of selected 2D and 3D synthetic datasets (e.g. SEG/EAGE Salt and SIGSBEE dataset), followed by a shift in focus to depth imaging of 3D land seismic datasets.