Study of an ESP's performance handling liquid-liquid flow and unstable O-W emulsions part II: Coupled CFD-PBM modelling

Abstract

The internal flow behavior of an ESP handling dispersed oil-water and emulsion flows remains quite unexplored. Previous studies have focused either on the individual droplet dynamics or on a simplified and limited modelling of the ESP's global performance. Hence, this study seeks to implement and analyze the applicability of a more robust and far-reaching CFD-PBM model which maintains a reasonable computational expenditure. Good agreement with experimental data was attained by the Eulerian-PBM framework (<10% error) and acceptable mean flow predictions were achieved with a less robust and computationally demanding VOF model (15% error). The internal flow behavior was noted to be governed by droplet size and effective viscosity variations, which induce the formation adverse pressure gradients leading to the emergence of backflow currents and eddies, particularly at higher oil fractions and lower flowrates. At higher flowrates and latter stages, well adapted flow is always attained, regardless of the mixture handled.