水平管稠油水环输送稳定性数值研究

Numerical Study on Stability of Water Annulus Transportation of Heavy Oil in Horizontal Pipe

流动稳定性问题是稠油水环输送的难点。使用CFD软件,从油水密度差、黏度差、油水两相速度几个因素出发展开研究。模拟结果表明,缩小油水密度差会减小压降梯度降低偏心率增加输油效率η,η最高可达11.54;油相黏度的增加虽然会增加压降梯度但输油效率会提高,η最高可达92.47。变水速情况下,水速过小会形成大压降的分层流,稳定水环形成后水速过大会增大管输总流量减小输油效率;变油速情况,油速增长会增加压降梯度,输油效率存在峰值,存在最优速度范围。

The stability of water annulus transportation of heavy oil poses a significant challenge.The CFD software was used to study the factors of oil-water density difference,viscosity difference and oil-water two-phase velocity.Simulation results demonstrate that reducing the oil-water density difference leads to decreased pressure gradient,reduced eccentricity,and increased oil transportation efficiency(η),and the maximumηcan reach 11.54.Although an increase in oil phase viscosity results in higher pressure gradient,it improvesηsignificantly,with a maximumηvalue reaching 92.47.In the case of variable water velocity,too small water velocity will form stratified flow with large pressure gradient.After the formation of stable water annular,too large water velocity will increase the total flux of pipeline and reduceη.The increase of oil velocity will increase the pressure gradient,and there is a peak value ofη,and there is an optimal velocity range.