The widespread occurrence of subtle trap accumulations offshore Brazil has led to the need for the development of a high resolution processing scheme that helps the delineation of these features. The process consists of three stages, the first of which is deterministic and stochastic deconvolution. The second stage is the deconvolution of the residual wavelet by means of spectral modeling. The last stage consists of the correction of the color of the reflectivity function using a model developed for the area. An important conclusion that is drawn from the model is that the acoustic impedance is not white. Rather it is as red as the corresponding reflectivity is blue. Successful results from the application of the proposed technique to real data indicate that the color compensation is of second order importance as compared with the first two stages of the proposed scheme.

At the present time, proper solutions for absorption modeling are based on wavefield extrapolation techniques which, in some instances, may be considered expensive. Two alternative, low cost, but incomplete solutions exist in the literature. The first models dispersion in the frequency domain in accordance with the Futterman dispersive relations but does not consider attenuation. The second models both attenuation and dispersion in the time domain but assumes a digital minimum‐phase formulation that results in an inadequate treatment of the dispersion. We show that this second solution can be adapted to perform attenuation and/or dispersion modeling in agreement with the Futterman attenuation‐dispersion relationships thus obviating the shortcoming mentioned above. Synthetic and real data examples are shown to illustrate the performance of the proposed algorithm.

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In this paper, we discuss the porting strategy and the achieved performance of Petrobras production code that implements Kirchhoff prestack time and depth seismic migration algorithms on a cluster of 64 GPUs and 256 CPU cores. The time migration of a real-world survey was 20 times faster in the full cluster with GPUs than in the full cluster without GPUs. The introduction of GPUs accelerated the depth migration of another real-world survey by a factor of 5. In both cases, a large fraction of the achieved gains were due to the porting strategy that privileges CPU-GPU A preliminary version of this work was published at the 21st International Symposium on Computer Architecture and High Performance Computing, SBAC-PAD 2009. 123 Int J Parallel Prog (2012) 40:290-312 291cooperation instead of pure GPU speed. Another strategy that contributed to the high gains was GPU overloading by multiple MPI processes. To cope with the heterogeneous load of real-world data, we developed a dynamic load balancing scheme that significantly speeds up computation.