热处理对添加防蜡剂长庆原油流动性及蜡沉积特性的影响研究

基于流变性测试和蜡沉积实验研究了热处理温度对添加EVA/PAMSQ复合防蜡剂的长庆原油的流动性和蜡沉积特性的影响。研究发现加剂原油依然具有热处理效果,50℃热处理条件下加剂原油的流动性改进效果较差,随着热处理温度升高至60、70和80℃,加剂原油的流动特性(如凝点、黏度、小振幅振荡剪切特性)显著改善。80℃热处理条件下,加剂原油的凝点已低于0℃,表明热处理与EVA/PAMSQ复合防蜡剂具有良好的协同效果。同时,随着热处理温度的升高,加剂原油的蜡沉积速率逐渐降低,但蜡沉积物的含蜡量逐渐升高,这可能不利于蜡沉积物的剥离。蜡沉积物呈现出非均质结构,表层蜡沉积物为凝油状,底层蜡沉积物具有比表层蜡沉积物更高的析蜡点和屈服强度。

Study on the Effect of Thermal Treatment on Flowablity and Wax Deposition Characteristics of Changqing Crude Oil Treated with Wax Inhibitor

The effects of thermal treatment temperature on the flowability and wax deposition characteristics of Changqing crude oil treated with EVA/PAMSQ paraffin inhibitor are investigated by means of rheological tests and wax deposition experiments.It is found that thermal treatment shows significant effects on the crude oil treated with the paraffin inhibitor.While the effect of thermal treatment is poor at 50℃,the flowability(such as freezing point,viscosity,small amplitude oscillatory shear characteristics)is significantly improved when the thermal treatment temperature is raised to 60,70,and 80℃.When the thermal treatment temperature is 80℃,the freezing point of the crude oil treated with the paraffin inhibitor is below 0℃,indicating that the thermal treatment and the EVA/PAMSQ inhibitor have a good synergistic effect.At the same time,with the increase of the thermal treatment temperature,the wax deposition rate of the crude oil treated with the paraffin inhibitor gradually decreased,but the paraffin content of the wax deposit gradually increased,which might make it more difficult to remove the wax deposit.The wax deposits showed a heterogeneous structure with tallow-like wax deposits at the surface while the bottom wax deposits had higher wax precipitation points and yield strength than the surface wax deposits.