Study On Safe Running Technology Of Lianluoxian Pipeline At Low-throughput Condition

Lianluoxian pipeline is currently at low-throughput condition and the out-station temperature of each station is relatively high, which lead to lack of the safe and economical operation scheme.Prior to drawing up the safe and economical operation scheme of Lianluoxian pipeline, the analysis of the physical and rheological property of crude oils should be done. The relationship between the pour point and the heat treatment temperature, between the density and the temperature, the heat absorption capacity and temperature, and the gum level, the asphaltine level, the wax level, the rheological property of crude oil can be gotten through indoor experiment. The simulation of Lianluoxian pipeline can be realized by using Stoner Pipeline Simulator, namely SPS. After mastering the analytical methods of steady operation state and transient operation state using SPS and combining the software modeling characteristics, Lianluoxian pipeline simulation model can be built according to field data. Afterwards, it is convenient to compare the simulation results with actual working state.The minimum throughput of pipeline allowed by thermodynamic conditions and the minimum throughput allowed by pipeline considering the maximum allowable solidifying time of shutdown can be calculated respectively by using formula method and simulation software. The methods to draw up the safe and economical operation scheme are determined. Meanwhile, the safe and economical operation schemes in different months and under different throughput are drew up by taking advantage of these methods. After comparing the safe and economical operation schemes with the actual working states on the scene in terms of economical efficiency, the shutdown and restart analysis of Lianluoxian pipeline can be realized using the simulation software, which includes the analysis of the temperature drop during pipeline shutdown and factors that influence the temperature drop, such as the pipe diameter, the soil thermal coefficient, the thermal coefficient of insulating course. The starting pressure and the time that the pressure and temperature are back to normal during the pipeline restart are also analyzed. At the same time, the calculated result using SPS will be compared with that of other software.And having a further understanding on the pipeline simulation software.