Prediction Model Based on the Grey Theory for Tackling Wax Deposition in Oil Pipelines

Problems involving wax deposition threaten seriously crude pipelines both economically and operationally. Wax deposition in oil pipelines is a complicated problem having a number of uncertainties and indeterminations. The Grey System Theory is a suitable theory for coping with systems in which some information is clear and some is not, so it is an adequate model for studying the process of wax deposition. In order to predict accurately wax deposition along a pipeline, the Grey Model was applied to fit the data of wax deposition rate and the thickness of the deposited wax layer on the pipe-wall, and to give accurate forecast on wax deposition in oil pipelines. The results showed that the average residential error of the Grey Prediction Model is smaller than 2%. They further showed that this model exhibited high prediction accuracy. Our investigation proved that the Grey Model is a viable means for forecasting wax deposition. These findings offer valuable references for the oil industry and for firms dealing with wax cleaning in oil pipelines.

凸台焊接对高频直缝电阻焊管残余应力的影响

在长输油气管道站场建设中,阀门、仪表和法兰的安装需要在主管道上开孔。高频直缝电阻焊管母材焊缝肉眼难以辨认,部分凸台安装位置距离电阻焊管焊缝很近甚至重合,因此凸台安装焊接对主管本身的影响程度需要深入研究分析。本文利用小孔法测量了高频直缝电阻焊管残余应力分布规律、凸台不同位置焊接对高频直缝电阻焊管原始残余应力的影响程度,发现电阻焊管开孔焊接凸台后,应力急剧上升,且凸台焊接对焊管纵焊缝上原始残余应力的影响远大于对管体的影响。