The effects of thermal history on the physical properties of Tu-Ha Oil in West Oil Pipeline

The influence of thermal history on the set point change laws of exported PPD-added Tu-Ha Oil in each pump station of West Oil Pipeline is researched under the condition of repeated heating with different initial temperatures. Results show that when the initial temperature is higher than 20 ℃, the effect of repeated heating on the set point of PPD-added oil is inconspicuous, or vice-versa; and when the repeated heating temperature is between 20 ℃ and 35 ℃, the oil's physical property will be worse. So, the tracking test is carried out, and the results show that when outlet temperature of the PPD-added Tu-Ha Oil is higher than 50 ℃ and its inlet temperature is higher than 20 ℃, the normal running of pipeline can be ensured. When the outlet temperature is between 20 ℃ and 35 ℃, the set point of PPD-added Tu-Ha Oil will be increased significantly and the normal running of pipeline can hardly be ensured. At present, the one-stop heater starting mode can basically provide a safety to the running of pipeline, however, if a changing throughput impacts the running safety of pipeline, the heating temperature for starting heater in intermediate heating/pumping station should keep away from the temperature range of 20 ℃ to 35 ℃.