D.M. Vishnevsky
S.A. Solovyev
V.V. Lisitsa

: Lobachevskii Journal of Mathematics

Attenuation is widespread in the Earths interior. However, there are several models where viscoelastic formations comprise as few as 10 to 20 % of the volume. They include near-surface and sea-bottom formation due to the low consolidation of the sediments, oil and gas reservoirs due to fluid saturation, etc. At the same time, the major part of the medium is ideally elastic. In this situation, the use of computationally intense approaches for the viscoelastic materials throughout the computational domain is prodigal. So this paper presents an original finite-difference algorithm based on the domain decomposition technique with the individual scheme used inside subdomains. It means that the standard staggered grid scheme approximating the ideally elastic model is used in the main part of the model. In contrast, the attenuation-oriented scheme is utilized inside viscoelastic domains. As the real-size simulations are applied in parallel via domain decomposition technique, this means that the elementary domains assigned to a single core (node) should be different for elastic and viscoelastic parts of the model. The optimal domain decomposition technique minimizing the computational time (core-hours) is suggested in the paper. It is proved analytically and confirmed numerically that for the models with up to 25% of viscoelasticity, the speed-up of the hybrid algorithm is about 1.7 in comparison with purely viscoelastic simulation.