A comprehensive comparison of the performance of several popular models to predict pressure drop in stratified gas–liquid flow with low liquid loading

The accurate prediction of pressure drop in gas–liquid flow through a pipeline under low liquid loading condition is the most prominent factor in designing gas-condensate transmission pipelines. The primary focus of this paper is on comparing the capabilities of several important mechanistic models introduced in the literature to predict the pressure gradient of gas–liquid flow through a pipeline in low liquid loading condition. An experiment was conducted to find the pressure gradients of air–water flow through a pipe with diameter of 25 mm at pressure of 1–3 bar for liquid holdups ranging from 0.01 to 0.08. The results of the models introduced by Taitel and Dukler (1976), Hart el al. (1989), Grolman-Fortuin (1997), Hamersma-Hart (1987), Chen et al. (1997), Baker et al. (1988), Zhang et al. (2003) and Fan (2005) were compared with the obtained experimental data for different range of liquid holdups. As a result, it was concluded that Taitel–Dukler and Zhang et al. models provided more reliable predictions than the other models did for a wider range of liquid holdups. The results also demonstrated that Zhang et al., Fan, Grolman-Fortuin, Hart et al. and Hamersma–Hart models are more successful in predicting the experimental data than Taitel–Dukler is where the liquid holdup is less than 0.02. However, there is no significant correlation between the accuracy of Taitel–Dukler model predictions and the amount of liquid holdup.