State of the Art of Experimental Studies and Predictive Methods for Slug Liquid Holdup

Abstract

Determination of gas entrainment in slug flow is crucial for the prediction of slug flow characteristics and separator performance. A summary of all available correlations and mechanistic models for the prediction of slug liquid holdup is presented. Additionally, an experimental data base for slug liquid holdup has been collected from available literature. The data base shows a gap for large diameter pipes, high pressure systems and high viscosity liquids. A comparison between the predictions of available models and correlations against the data base is presented, identifying the range of applicability of the different methods. The correlations have been tuned with the new data showing an improved performance. Also, the uncertainties of the correlations parameters are evaluated and presented. Based on this study, a recommendation for the best method for predicting the slug liquid holdup is provided.

Prediction of slug liquid holdup in high viscosity liquid and gas two-phase flow in horizontal pipes

“…capacitance sensor, gamma ray densitometer or quick closing valve. This concept is clearly shown and thoroughly discussed in Pereyra et al (2012) comparative study.…”

“…A detailed literature review on the predictive models by revealed that there is no single accurate model for all flow conditions, and a tradeoff between simplicity and accuracy has to be considered in the selection of a predictive model. A comprehensive evaluation study of slug liquid holdup correlations and models by Pereyra et al (2012) revealed a major gap in the literature for high viscosity slug liquid holdup predictive models. In addition, based on Pereyra et al (2012) large data base for low liquid viscosity horizontal and near-horizontal conditions, Gregory et al (1978) was found to be the most accurate correlation in addition to its main advantage of simplicity.…”

“…A comprehensive evaluation study of slug liquid holdup correlations and models by Pereyra et al (2012) revealed a major gap in the literature for high viscosity slug liquid holdup predictive models. In addition, based on Pereyra et al (2012) large data base for low liquid viscosity horizontal and near-horizontal conditions, Gregory et al (1978) was found to be the most accurate correlation in addition to its main advantage of simplicity. On the other hand, the Zhang et al (2003c) slug liquid holdup mechanistic model was found to be the most accurate model for their entire data base including upward vertical flow, although it is computationally complex.…”

Unified drift velocity closure relationship for large bubbles rising in stagnant viscous fluids in pipes

“…The uncertainty of the fitted parameters can be propagated to the calculated drift velocity using series Taylor expansion, assuming that the parameters are mutually independent and normally distributed. This procedure was shown by Pereyra et al (2012).…”

Investigation and prediction of slug flow characteristics in highly viscous liquid and gas flows in horizontal pipes

“…The reason is that their correlations were developed considering liquid viscosity effects and experiments were conducted by using liquids with relative high viscosity. The correlation of Gregory et al(1978), which is proved to have a widely application in low viscosity liquid cases (Pereyra et al, 2012;Al-Safran et al, 2013), 2000Gregory 1978Kora 2011Al-Safran 2013Predicted slug liquid holdup…”