Improved Holdup and Pressure Drop Predictions for Multiphase Flow with Gas and High Viscosity Oil

In this paper we present a new set of experiments with high density gas and two different viscous oils. Furthermore a new steady state model is proposed for two-phase gas liquid flow with viscous oil. The experiments were obtained in a 69 mm ID horizontal pipe using high-density SF6 gas at 4 and 8 bara. The oils were Nexbase 3080 and a mixture of Nexbase 3080 and Exxsol D80, with viscosities of 100 cP and 32 cP. The experiments focused on the transition from laminar to turbulent flow, and the transition from stratified to slug flow. The measured quantities include the liquid holdup, pressure drop and flow regime. The model framework includes stratified, slug and dispersed bubble flow. Suitable existing closure laws have been identified and they were improved where necessary. Predictions with the new model are compared to the new experimental data.