抽油杆直径对井筒中混合流体压降影响分析

Effect of Sucker Rod Diameter on Pressure Drop of Gas-liquid Two-phase Pipe-flow in Wellbore

在井筒中,当抽油杆直径改变时,油管与抽油杆间的环形面积发生变化,气液混合密度、持液率、混合物沿管路流动的压降等参数也会发生变化。为研究井筒中抽油杆直径对压降的影响规律,选用Beggs-Brill模型,利用大庆油田采油一厂的生产数据,通过编程对压降进行数值计算。结果表明:随着抽油杆直径增大,重位压降逐渐减小,摩阻压降逐渐增大,总压降先减小后增大,存在最佳抽油杆直径。为抽油机井节能降耗提供理论依据。

In wellbore,as the change of sucker rod diameter,the area of annular space between sucker rod and oil tube changes and some parameters such as mixture density, liquid holdup and pressure drop along the pipe will change, too. In order to study the effect regular pattern of sucker rod diameter on pressure drop in wellbore, based on Beggs-Brill model and production data from DaQing oilfield,pressure drop was calculated numerically with programming. The result showed that with the increase of sucker rod diameter, gravitative pressure drop decreases gradually, fric- tion drop increases and the overall pressure drop decreases first and then increases,a best sucker rod diameter can be acquired. The results can provide theory basis for the research on saving ener- gy and reducing consumption in oil pumping well.