Experimental Study on the Flow Regimes and Pressure Gradients of Air-Oil-Water Three-Phase Flow in Horizontal Pipes

Luai M Al-Hadhrami,S M Shaahid,A Al-Sarkhi,Lukman O Tunde

doi:10.1155/2014/810527

Luai M Al-Hadhrami, S M Shaahid + Show 2 more

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https://doi.org/10.1155/2014/810527

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Abstract

An experimental investigation has been carried out to study the flow regimes and pressure gradients of air-oil-water three-phase flows in 2.25 ID horizontal pipe at different flow conditions. The effects of water cuts, liquid and gas velocities on flow patterns and pressure gradients have been studied. The experiments have been conducted at 20°C using low viscosity Safrasol D80 oil, tap water and air. Superficial water and oil velocities were varied from 0.3 m/s to 3 m/s and air velocity varied from 0.29 m/s to 52.5 m/s to cover wide range of flow patterns. The experiments were performed for 10% to 90% water cuts. The flow patterns were observed and recorded using high speed video camera while the pressure drops were measured using pressure transducers and U-tube manometers. The flow patterns show strong dependence on water fraction, gas velocities, and liquid velocities. The observed flow patterns are stratified (smooth and wavy), elongated bubble, slug, dispersed bubble, and annular flow patterns. The pressure gradients have been found to increase with the increase in gas flow rates. Also, for a given superficial gas velocity, the pressure gradients increased with the increase in the superficial liquid velocity. The pressure gradient first increases and then decreases with increasing water cut. In general, phase inversion was observed with increase in the water cut. The experimental results have been compared with the existing unified Model and a good agreement has been noticed.

Highlights

Multiphase flow occurs in oil/gas, chemical, civil, and nuclear industries
It is imperative to fully understand and study the flow rates, flow regimes/patterns, liquid-hold-up/ water cut (WC), pressure gradients, and volume fractions of gas, oil, and water going into the pipelines during transportation of petroleum products
The three different fluids were passed into the horizontal pipeline and the flow patterns were observed while the pressure gradients were measured/recorded

Summary

Introduction

Multiphase flow occurs in oil/gas, chemical, civil, and nuclear industries. The dominant occurrence of gas-oil-water threephase flow in the petroleum industry requires sound knowledge of the behavior of multiphase flow. The most important characteristic of multiphase flow is its flow pattern (physical distribution of the phases within the enclosure they flow through) and the pressure gradient along the horizontal pipeline. In this regard, it is imperative to fully understand and study the flow rates, flow regimes/patterns, liquid-hold-up/ water cut (WC), pressure gradients, and volume fractions of gas, oil, and water going into the pipelines during transportation of petroleum products. It is important to better understand/predict/investigate the flow characteristics during petroleum production at different flow conditions such as the geometrical configuration of the pipeline, the physical properties of the fluids, and flow rates. There is a need to‘accurately investigate and predict the flow configurations and the pressure drop [1, 2]

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