管输原油物性变化和加剂效果分析

Analyses of physical property changes of pipeline transporting crude oil and pour point depressant effect

津华线投产以后,经过持续监测发现,管输原油物性发生了较大的变化,同时降凝剂作用的稳定性也随之降低,管输油品凝点随着输送距离的增加而逐渐升高。首先通过对投产之前、投产初期、正常运行之后油品物性监测,揭示出津华线投产前后不加剂冀东油凝点由21℃升高至28℃,同时降凝剂的作用效果逐渐减弱的现象;而后从热处理温度、取样问题、流速变化、降凝剂失效等方面进行了现场跟踪对比测试,进一步确定降凝剂作用效果存在稳定性不足的问题,并得出管输过程中只要热处理温度足够,加剂油凝点仍可恢复到较低水平的结果;最后指出将进一步改进降凝剂以提升降凝剂的性能。

After Jinhua crude oil pipeline was put into production,it has been found by continuous monitoring that the physical properties of the crude oil in the pipeline change greatly,and the stability of the pour point depressant also decreases.With the increase of transportation distance,the freezing point of pipeline oil gradually increases.First of all,through the physical property monitoring of oil products at the stages of before production,commissioning and normal operation,it is revealed that the freezing point of the Jidong oil increases from 21℃to 28℃before and after commissioning,and the effect of pour point depressant gradually weakens.Then the field tracking and comparative tests are carried out from the aspects of heat treatment temperature,sampling problem,flow rate change,pour point depressant failure and so on.It is further determined that there is a problem of insufficient stability in the effect of pour point depressant,and the result is got that as long as the heat treatment temperature is sufficient,the pour point of oil can still be restored to a lower level in the process of pipeline transportation.