大管径不同井斜油水两相流流型数值模拟

Numerical Simulation of Oil-water Two-phase Flow Pattern in Large Diameter and Different Inclined Wells

通过ICEM CFD建立倾角θ为±20°、±15°、±10°、±5°和0°(完全水平),内径为0.124m,长度为20m的井筒,利用FLUENT中的VOF多相流模型对大管径不同斜度井中的油水两相流进行数值模拟,得出不同油水混合速度、不同含水率和不同倾角时的流动变化规律;结合Trallero J L的流型分类方法,根据模拟得到的油水两相分布图划分了6种流型,并制作了以混合速度、倾角为坐标的流型图。倾角θ=0°(井筒水平)时,流型以分层流为主,随着混合速度的增加,其逐渐变为界面混杂的分层流;若含水率逐渐增大,流型将转变为油-油包水、油包水或水包油-水、水包油;倾角θ>0°(井筒上倾)时,流型随流速的增大提前发生转变,并且水相出现回流,局部持水率变大;倾角θ<0°(井筒下倾)时,水相在底部加速流动,局部持水率变小。计算结果与相关实验结果比较吻合。

Utilizing ICEM CFD,we establish wellbore whose angles are±20°、±15°、±10°、±5°and 0°(completely horizontal),inner diameter is 124 mm and length is 20 m.Using VOF multiphase flow model of FLUENT,we conduct numerical simulation of oil-water two-phase flow in different inclined wells,and obtain the regularities of oil-water two-phase flow pattern in various angles,total mixture flowrate and water-cut;Combing with Trallero's flow pattern classification,we divide 6 kinds of flow patterns oil-water two-phase distribution map by numerical simulation and plot flow pattern figures using angel and flow rates as coordinates.Whenθ=0°,the flow patterns are mainly stratified flow.With the increasing of flow rate,flow patterns turn to interface mixed stratified flow;if water flow rate gradually increases,the flow pattern will be transformed into oil-water-in-oil,water-in-oil or water-oil-in-water and oil-inwater.Whenθ>0°,the flow pattern changes ahead with flow rate and water-phase flows back and partial water-cut increases.Whenθ<0°,water flow is faster on the bottom and partial watercut declines.The calculated result is accordance with the related experimental results.