空心杆泵上循环热水加热降粘的数值研究

Numerical Study on Heating and Viscosity Reduction of Circulating Hot Water in Hollow Rod Top Pump

稠油开采过程中,准确预测井筒温度及原油的粘度变化对选择合适的采油工艺具有指导意义。运用计算流体力学(Computational fluid dynamics,CFD)数值模拟方法,建立空心杆泵上循环热水加热降粘数值模型,进行数值求解,得出循环热水及原油沿程温度和粘度变化规律,并建立目标函数研究平均降粘及减阻效果。结果表明,根据循环热水进口温度的不同,原油在距离进口30～35 m附近温度达到峰值,随后温度呈降低趋势;循环热水入口温度为分别为80℃、70℃和60℃时,原油全管程的降粘率分别为97.3%、96.7%和94.6%。

It is of great significance that well bore temperature and viscosity of crude oil are predicted accurately for the selection of oil production technology in the process of exploiting heavy oil.Computational fluid dynamics（CFD） numerical simulation method is used and the numerical simulation model of heating and viscosity reduction of circulating hot water in hollow rod top pump is established.The curves of oil temperature and viscosity along the tube are obtained by using numerical solution for the flow field with different circulating water inlet temperature.The viscosity reduction rate along tube is calculated and drag reduction effect is analyzed by using objective function.The results show that the temperature of crude oil reaches peak value at 30～35 m away from the inlet,then the temperature decrease;when the inlet temperature of circulating water are 80 ℃,70 ℃ and 60 ℃,the viscosity reduction rate of the tube reach 97.3%,96.7% and 94.6% respectively.