Analysis on the Part-gel-shutdown Accident in Huoshaoshan-Beisantai Crude Oil Pipeline

By analyzing a waxy crude oil pipeline's part-gel-shutdown accident, following concepts are recognized: (l)For a waxy crude oil pipeline, downstream outlet temperature of the pipeline must be 3 C higher than its pour point; (2)when a part-gel-shutdown waxy crude oil pipeline will be restarted, three processes dominate the changes of pressure and flow rate as well as the speed of pipeline's normalization. First one is filling the empty space caused by shrink or weight-flow. Second is yielding the end-segment lower temperature gel crude oil that has yield stress. The last one is scouring and cleaning the part-gel crude oil nearby pipeline wall and recovering normal flow rate.