Research On Evaluation Of Pour Point Depressant And Operation Plan Of Shixi-Karamay And Karamay-Dushanzi Pipelines In Winter

Compared with previous years,the crude oil throughout of Shixi-Karamay and Karamay-Dushanzi pipelines decreased in winter,due to the reduction of crude oil production in Xinjiang oil field.In order to ensure the safe and economical operation of the pipelines in winter,the two pipelines adopt the transportation technology of adding pour point depressants(PPDs).Therefore,the pipeline transportation technology is optimized by conducting experimental studies using the PPDs with good stability.Finally,a safer and more economical operation plan is determined.In this paper,indoor evaluation experiments are conducted to evaluate the stability of the PPDs used in Shixi-Karamay and Karamay-Dushanzi pipelines.Operation plans of pipelines adding PPDs in winter are simulated through pipeline transportation simulation experiment.Before the winter,the pipelines are subjected to the field experiments of adding PPDs and the operation plans in winter are determined.The experimental results show the stability of the PPDs used in Shixi-Karamay and Karamay-Dushanzi pipelines is good.Pipeline transportation simulation experiments also show that the PPDs have better modification effect.When adding the PPD to the Shixi-Karamay pipeline in winter,the outlet temperature of Shixi station should be controlled at 55°C or higher.The dosage should be controlled at 30 ppm or more.There is no need to use the furnace at the Shike intermediate station during the winter.When adding the PPD to the Karamay-Dushanzi pipeline in winter,the outlet temperature of Zongzhan station and Si pump station should be controlled at 55°C or higher.The dosage should be controlled at 20 ppm or more.According to the actual situation,it can be judged whether the Six pump station needs to use the furnace.After optimizing the winter operation plans of the Shixi-Karamay and Karamay-Dushanzi pipelines,at least 784.6 thousand yuan in operating costs can be saved each year.Furthermore,in this paper,BP neural network models based on Bayesian regularization algorithm(BRANN)are established to predict the gel point and viscosity of PPD treated crude oil affected by shear.The mean absolute error(MAE)of the gel point predicted by the BRANN model is not greater than 0.86°C.The mean absolute percentage error(MAPE)of the viscosity or apparent viscosity(1140 sets of data)predicted by the BRANN model is 13.93%.