SUMMARYAlthough time-domain depth migration techniques have been successfully ported to run on modern hardware accelerators, their ultimate obstacle is the I/O overhead present during the imaging step. Frequency-domain depth migration algorithms overcome this limitation and can exploit the full potential of new computing technologies. In particular, our implementation of Phase Shift Plus Interpolation (PSPI) method is characterized by fast running time, good quality results under lowsignal-to-noise ratio conditions and excellent results for steep dips. We provide a novel computational dataflow scheme to perform acceleration of PSPI on a generic dataflow engine. We present speedup results obtained on the state-of-the-art dataflow technology for synthetic VTI datasets. Our measurements indicate that a dataflow approach can achieve high speedups despite larger and larger computational domains, increased complexity of the anisotropic approach and the I/O overhead during angle-gathers calculation.

SummaryIncreasingly challenging exploration targets with respect to the geological complexity and data quality require more accurate seismic imaging. The common-offset CRS method provides an extension of the CRS technology to such targets as we demonstrate in this case study for complex 2D over thrust data. While both zero-and common-offset CRS stack provide similar noise reduction compared to the conventional PreSTM in areas with relatively simple structure and good coupling, the common-offset results are far superior on very poor data. Moreover, using the CO CRS stack in depth velocity model building can help in event picking and provides a better defined semblance. IntroductionExploration targets become more and more complex and standard seismic imaging methods might no longer be adequate. This also holds for time imaging techniques as they constitute the input for depth migration and velocity model building or updating. Traditional time imaging methods are often based on simplifying assumptions and might fail for complex targets and / or long offsets.

The formulation and practical implementation of methods to automatically obtain an image of the earth's interior are long-term dreams in the geophysical community. This problem has stimulated the curiosity of geophysicists, and its solution would dramatically change seismic processing and improve oil and gas exploration. Several attempts have been made in the last two decades to obtain such a result, and nowadays, every oil company and contractor is still strongly committed to achieving it. In this effort, velocity-independent time imaging, driven only by data, is possible.