含蜡原油管道再启动过程热力水力耦合特性研究

发布时间：2018-12-30 17:15

【摘要】：原油的运输是石油生产加工过程中的重要环节,在石油的生产、加工、销售等环节,自始至终都离不开管道。原油在管道输送过程中,不可避免的会发生自然灾害、管线维修和油田停电等情况;另一方面受输量影响,也可能出现被迫间歇停输现象,因此在生产操作过程中会出现计划停输和事故停输。停输后再启动过程能否顺利进行将直接影响到管线运行的安全与成本。为了保障含蜡原油管道安全稳定运行,本文研究了埋地含蜡原油管道停输再启动过程。为实现含蜡原油管道安全经济地运行,以原油管道正常运行工况为基础,建立停输工况下的传热模型,采用有限元法对模型求解,计算不同停输时间下管道的沿程温度,并绘制夏、冬两季埋地管道的土壤温度场。根据原油管道再启动工况的热力与水力、管内原油与管外介质相互耦合的特征,考虑原油收缩性、压缩性以及触变性对再启动特性的影响,以管内原油的连续性方程、动量守恒方程、能量守恒方程及相关边界条件和初始条件为基础,建立停输再启动过程非稳态热力水力耦合模型。采用冲击波理论结合特征线法对再启动过程求解,应用Matlab编制停输再启动计算程序,并对某埋地原油管道夏、冬两季进行模拟计算,分析再启动过程中管道首末端油温和沿线流量随时间的变化规律,以及再启动时管道首端的压力变化。并以管道极限承压能力为判据,确定含蜡原油管道夏冬两季安全停输时间,为管道安全运行提供了可靠的理论依据,进而指导管线的安全操作与管理。
[Abstract]:The transportation of crude oil is an important link in the process of petroleum production and processing. In the course of pipeline transportation, natural disasters, pipeline maintenance and oil field outages will inevitably occur. On the other hand, due to the influence of the quantity of transportation, the phenomenon of forced intermittent shutdown may also occur, so there will be planned shutdown and accident shutdown in the process of production and operation. The safety and cost of pipeline operation will be directly affected by the success of restart process after shutdown and transmission. In order to ensure the safe and stable operation of waxy crude oil pipeline, this paper studies the shutdown and restarting process of buried waxy crude oil pipeline. In order to realize the safe and economical operation of waxy crude oil pipeline, based on the normal operation condition of crude oil pipeline, the heat transfer model under shutdown condition is established. The finite element method is used to solve the model, and the pipeline temperature along the pipeline under different shutdown time is calculated. The soil temperature field of buried pipeline in summer and winter was plotted. According to the thermodynamic and hydraulic characteristics of the restarting condition of the crude oil pipeline and the coupling characteristics between the crude oil and the medium outside the pipe, the effects of the shrinkage, compressibility and thixotropy of the crude oil on the restarting characteristics are considered, and the continuity equation of the crude oil in the pipe is taken into account. Based on momentum conservation equation, energy conservation equation and related boundary conditions and initial conditions, the unsteady thermodynamic and hydraulic coupling model of shutdown and restarting process is established. The shock wave theory combined with the characteristic line method is used to solve the restarting process, and Matlab is used to compile the program of stopping and restarting, and to simulate the summer and winter of a buried crude oil pipeline in summer and winter. The variation of oil temperature and flow rate along the first end of the pipeline with time and the pressure variation of the first end of the pipeline during the restarting process are analyzed. Based on the limit pressure bearing capacity of pipeline, the safe shutdown time of waxy crude oil pipeline in summer and winter is determined, which provides a reliable theoretical basis for the safe operation of pipeline, and then guides the safe operation and management of pipeline.
【学位授予单位】：东北石油大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TE832

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