Upward gas–liquid two-phase flow after a U-bend in a large-diameter serpentine pipe

Abstract

We present an experimental study on the flow behaviour of gas and liquid in the upward section of a vertical pipe system with an internal diameter of 101.6 mm and a serpentine geometry. The experimental matrix consists of superficial gas and liquid velocities in ranges of 0.15 to 30 m/s and from 0.07 to 1.5 m/s, respectively, which cover bubbly to annular flow. The effects on the flow behaviours downstream of the 180° return bend are significantly reduced when the flow reaches an axial distance of 47 pipe diameters from the U-bend. Therefore, reasonably developed flow is attained at this development length downstream of the bend. Other published measurements for large-diameter film thickness show similar trends with respect to the superficial gas velocity. However, the trends differ from those of small-diameter pipes, with which the film thickness decreases much faster with increasing gas flow. As a result, only a few of the published correlations for small pipe data agreed with the experimental data for large pipe film thickness. We therefore modified one of the bestperforming correlations, which produced a better fit. Qualitative and statistical analyses show that the new correlation provides improved predictions for two-phase flow film thickness in large-diameter pipes.

Wall Slip and Flow Characteristics of Gas–Liquid–Solid Phase Coupling Flowing in Horizontal Pipelines

“…Most existing research focuses on the shape, average size, and other parameters of solid particles, and also discusses their influence on the flow characteristics of solid–liquid mixtures while ignoring the effects of flow velocity, pipe size, and wall roughness. − Moreover, oil exploitation is often accompanied by the production of natural gases. Research on gas–liquid two-phase pipe flow based on this background is quite mature, and a variety of flow parameter testing technologies have been developed to study the conventional gas–liquid two-phase flow pattern conversion, pressure fluctuation, and phase distribution. − With the development of unconventional resources in the petroleum industry, research on the flow law of multiphase in pipelines has gradually become an important research topic. It is therefore very important to study the critical parameters of the flow pattern transition under different flow conditions.…”

Sand minimum transport conditions in gas–solid–liquid three-phase stratified flow in a horizontal pipe at low particle concentrations

“…It consists of a horizontal pipe with an inner diameter of 0.0504 m. The 2-inch test rig constitutes a loop length of 25 m; 10.5 m of that is PVC pipe that serves as the water supply inlet and the remainder is of a Perspex pipe material. Two flush-mounted conductivitybased sand monitoring sensors (uncertainty of ±3.3% and identical to those employed by(Aliyu et al, 2017bAliyu et al, 2017;Almabrok et al, 2016) in measuring liquid film thickness), given inFigure 1 (b)and (c) were installed about 6 m after the air and sand injection point along the horizontal pipe but 0.21 m apart from each other. The second sand sensor was placed within the conductivity ring sensors (Fajemidupe, 2016).…”