InterPore2021

A sequential implicit solver for two-phase subsurface flows using the Multiscale Robin Coupled Method

2 Jun 2021, 15:30

15m

Oral Presentation (MS14) Uncertainty Quantification in Porous Media MS14

Speaker

Franciane Rocha (University of Sao Paulo)

Description

Multiscale domain decomposition methods are a suitable choice when dealing with huge meshes arising from the discretization of the equations modeling multiphase flows in reservoir simulations. They allow the global solution to be computed in coarse meshes, while detailed basis functions are produced locally (usually in parallel) in a much finer grid. We are concerned with the solution of non-linear two-phase flow models using the recently developed Multiscale Robin Coupled Method (MRCM, [1]). This method allows for great flexibility on the choice of interface spaces that couple local solutions, with a clear advantage in highly heterogeneous porous media when compared to some standard multiscale mixed methods. In the presence of strong heterogeneities, it is well known that explicit schemes for the transport of saturation suffer from severe time-step restrictions. Therefore we investigate the combination of the MRCM with implicit transport schemes, allowing for the use of large time steps when compared to explicit time integration approaches. A sequential implicit strategy is proposed, with different trust-region algorithms to ensure the convergence of the transport solver. Improvement in the accuracy of the MRCM is investigated, considering alternative choices for the interface spaces other than the classical polynomials, since they are not optimal for high-contrast channelized permeability fields. Our numerical results have shown that the proposed method yields accurate and computationally efficient results for two-phase subsurface flows.

References

[1] R.T. Guiraldello, R.F. Ausas, F.S. Sousa, F. Pereira, and G.C. Buscaglia. The multiscale Robin coupled method for flows in porous media. J. Comput. Phys., 355:1-21, 2018.