Study on the Pressure Drop Variation and Prediction Model of Heavy Oil Gas-Liquid Two-Phase Flow

Shanzhi Shi,Jie Li,Congping Liu,Xingkai Zhang,Ruiquan Liao,Xinke Yang,Jiadong Liao,Reza Rezaee

doi:10.1155/2021/8813167

Abstract

To explore the pressure drop variation with the viscosity of heavy oil gas-liquid two-phase flow, experiments with different viscosity gas-liquid two-phase flows are carried out. The experimental results show that the total pressure drop increases with increasing liquid viscosity when the superficial gas and liquid flow rates are the same. The liquid superficial velocity is 0.52 m/s, and the superficial gas velocity is 12 m/s in the vertical and inclined pipes, as there is a negative friction pressure drop when the superficial gas and liquid velocities are small. Additionally, the increased range of the total pressure drop decreases with increasing liquid viscosity. Considering the heavy oil gas-liquid two-phase flow, a prediction model of the pressure drop in high-viscosity liquid-gas two-phase flow is established. The new model is verified by experimental data and compared with existing models. The new model has the smallest error, basically within 15%. Based on the prediction of the wellbore pressure distribution of four wells in the BeiA oilfield, the new model prediction results are closer to the measured results, and the error is the smallest. The new model can be used to predict pressure drops in high-viscosity gas-liquid two-phase flow.

Highlights

As recoverable reserves of conventional crude oil are decreasing worldwide, heavy oil plays an important role in the energy supply
When the apparent gas and liquid flow rates are small and a negative friction pressure drop occurs, the negative value of the negative friction pressure drop increases with increasing viscosity of the liquid because the gravity pressure drop increases with increasing viscosity and the increased range of the total pressure drop decreases with increasing liquid viscosity
Analysis of the experimental data shows that the total pressure drop increases with increasing liquid viscosity when the superficial gas and liquid flow rates are the same and that the liquid superficial velocity is 0.52 m/s and the superficial gas velocity is 12 m/s in the vertical and inclined pipes

Summary

Introduction

As recoverable reserves of conventional crude oil are decreasing worldwide, heavy oil plays an important role in the energy supply. Schmidt et al [4] conducted an experimental study on the phase and velocity distributions of the gas-liquid two-phase flow of a high-viscosity fluid (viscosity up to 7000 mPa∙s) in a vertical upward pipe. Zhang et al [5] summarized the research progress of high-viscosity oil and compared it with the multiphase flow of low-viscosity oil (including the flow pattern, pressure gradient, and liquid holdup). The experimental results indicate that the flow behaviors of high-viscosity oil and low-viscosity oil are quite different. Jeyachandra et al [6] studied the effects of high viscosity and pipe diameter on the drift velocity of horizontal and upward inclined pipes by conducting gas-liquid twophase flow experiments and proposed a new high-viscosity drift velocity model suitable for horizontal to vertical pipes.

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