水平管内水环输送模拟稠油减阻特性

Drag reduction characteristics of water annulus transportation of simulated heavy oil in horizontal pipeline

基于自主设计加工并搭建的水环输送稠油减阻模拟管路系统,采用500#白油模拟稠油,试验研究了稠油在水环作用下的水平管流阻力特性,分析了油相表观流速(0.3~1.0m/s)、水相表观流速(0.11~0.72m/s)及入口含水率(0.13~0.49)对水润滑管流流型特征及减阻效果的影响。结果表明:环状水膜可有效隔离并润滑油壁界面,油-水两相流流型总体上呈稳定的偏心环状流结构;水环输送可大幅降低管道输送过程中的压降,其压降值仅为相同油流量下纯油输送压降的1/55~1/27;当入口含水率为0.13~0.27时,水环输送的效能显著,输油效率均高于40;油相表观流速和入口含水率的增加会增大单位管长压降,降低水环输送的减阻效果和输油效能。

On the basis of self-designed and built pipeline system of drag reduction on water annulus transportation of heavy oil,the flow resistance characteristics of heavy oil simulated by 500#white oil under the action of water ring in horizontal pipe were experimentally studied.The influence of 0.3—1.0m/s oil superficial velocities,0.11—0.72m/s water superficial velocities and 0.13—0.49input water volume fractions on the flow patterns characteristics and drag reduction effect of water lubricated pipe flow was analyzed.The experimental results showed that the oil-water two-phase flow exhibits a typical eccentric annular flow pattern,where the annular water film can effectively isolate and lubricate the interface of oil phase and pipe wall.The pressure drop in the process of pipeline transportation can be substantially reduced by the water ring transportation,which is only 1/55—1/27 of the pressure drop when the oil is delivered separately under the same oil flow rate.The oil transportation efficiency was in a high level,which was all above 40,when input water fraction is in the range of 0.13—0.27.With the increase of oil superficial velocity and water input fraction,the pressure drop per unit pipe length increases,while the drag reduction effect and oil delivery efficiency of water annulus conveying decrease.