A Study on the Shutdown and Restart Course of Dong-Huang Looping Line

With rheological change of the oil from Shengli Oilfield studied and the mathematical model for pipeline shutdown and restart established, the paper calculates the shutdown and restart course of Dong-Huang Looping Line using numerical method. Industrial field test is made successfully with its actual measured data basically in conformation with the data calculated. It.can be noted through calculation that a heavy rain along oil pipeline route may result in low soil temperature, increased heat leak from oil flow, and a small drop of oil temperature after 30-40h shutdown, and that, due to soil damping, the oil in.buried pipeline has no change in temperature 30h after, shutdown in winter with the atmospheric temperature having a drop of 10 ℃. When restarted after shutdown of heated oil pipeline, an initial changing period will be experienced because of oil's cold contact effect. In this period, pump discharge shall be controlled to prevent difficult pumping.