An experimental investigation of the stochastic nature of slug flow

Abstract

Slug flow is widely encountered in oil and gas systems. It has an unsteady hydrodynamic behavior that motivated the development of mechanistic models to better understand and quantify the parameters of the flow. The present work investigated several slug flow conditions through an experimental campaign that was performed in a 2-in ID horizontal pipe facility. The experimental data were statistically analyzed and they indicated the suitability of a lognormal distribution to model the flow characteristics, such as slug length, film length, and frequency. Based on the mean results, slug and film lengths tend to increase as more gas is present in the flow. The mean frequency indicated that higher frequencies are obtained with lower gas fractions. All the slugs from each test were individually studied using different approaches to analyze the data. The results suggest the existence of a relationship between the slug and film lengths when the slug unit is identified starting from a film region followed by a slug region. The values of the coefficient of determination for the relation between slug length and film length indicate a possible influence of other flow parameters of stochastic nature, such as slug liquid holdup, that could affect the behavior of the slugs.