Optimal Time-Step for Coupled CFD-DEM Model in Sand Production

Abstract

The coupled Computational Fluid Dynamics and Discrete Element Method (CFD-DEM) is a useful tool for modeling the dynam ics of sand production that occurs in oil and gas reservoirs. To perform accurate, physically relevant and efficient calculations, the optimal size of the simulation time-step should be selected. In this study, we investi gate the selection of an appropriate time-step interval between CFD and DEM models in sand production simulations. The CPU time, speedup and root mean squared relative error of the obtained results are exam ined to compare the sand production phenomenon at different coupling numbers. Most of the results including the final sand production rate, bond number and bond ratio indicate that the simulations with coupling numbers of N = 10 and N = 100 produce more accurate results. More over, these outcomes demonstrate significant improvements in terms of acceleration of the modeling process.