MH油田常温转输系统含水原油黏壁温度研究

Study on Viscous Wall Temperature of Water-containing Crude Oil in Ambient Temperature Transfer System of MH Oilfield

MH油田原油含蜡易凝,冬季极寒(-40℃)环境下常温集输过程中原油黏壁概率增大,威胁管道安全运行。因此,亟需判断MH油田在实际运行工况以及未来工况下的常温转输可能性。通过改进后的冷指实验测得MH油田各转油站油品在不同含水率和不同流速下的黏壁温度,并采用极端梯度上升(XGBOOST)算法开展黏壁温度预测。其结果表明,M131、M18、BL、M2转油站原油在55%~80%含水率和0.90~2.72 m/s流速下的黏壁温度均低于凝点0.25~11.01℃,随含水率和流速增大,原油黏壁倾向减弱,黏壁温度降低。不同工况下XGBOOST算法黏壁温度预测结果与实验结果平均误差仅为8.36%。原油黏壁温度与各因素的重要度排序为含水率、原油凝点、流速,XGBOOST算法可用于预测MH油田转输系统变工况下常温转输的可行性。

The crude oil in MH oilfield contains wax and is easy to condense,and the probability of crude oil sticking to the wall increases in the process of ambient temperature gathering and transportation in winter extreme cold(-40℃),which threatens the safe operation of pipeline.Therefore,there is an urgent need to determine the possibility of ambient temperature transfer in the MH field under actual operating conditions as well as under future conditions.The viscous wall temperatures of oils from various transfer stations in the MH field at different water contents and different flow rates were measured by a modified cold finger experiment,and the extreme gradient ascent(XGBOOST)algorithm was used to carry out viscous wall temperature prediction.The results show that viscous wall temperatures of crude oil at M131,M18,BL and M2 transfer stations at 55%-80%water content and 0.90-2.72 m/s flow rate are all lower than the freezing point by 0.25-11.01℃,and the tendency to viscous wall of the crude oil decreases with the increase of the water content and mobility,and the viscous wall temperature decreases.The average error between the viscous wall temperature prediction results of XGBOOST algorithm and the experimental results under different working conditions is only 8.36%.The importance of crude oil viscous wall temperature with respect to each factor is ranked as follows:water content,crude oil freezing point,flow rate,and the XGBOOST algorithm can be used to predict the feasibility of ambient temperature transfer under variable operating conditions in the MH oilfield transfer system.