A New Model for Predicting Slug Flow Liquid Holdup in Vertical Pipes with Different Viscosities

The development of heavy oil has attracted attention in recent times. With increasing fluid viscosity, slug flow has become the most common flow pattern in oil and gas pipeline flow. The accurate prediction of slug flow parameters is an urgent problem to be solved in heavy oil development. In this paper, gas–liquid two-phase flow experiments with different viscosities were carried out in a 60-mm vertical pipe. The superficial velocity ranges of gas and liquid were 0.51–7.42 m/s and 0.08–0.21 m/s, respectively. Based on the measured data, the investigation revealed that liquid holdup increases with an increase in viscosity and superficial liquid velocity. This study presents a new liquid holdup model of slug flow for viscous two-phase flow in vertical pipes. Based on the statistical analysis, the proposed correlation accurately predicts the liquid holdup of slug flow in a vertical pipe for the present measured data and performs best in comparison with existing correlations.