高含蜡原油管道低输量状态下的安全经济运行技术研究

发布时间：2018-01-07 09:16

本文关键词：高含蜡原油管道低输量状态下的安全经济运行技术研究　出处：《东北石油大学》2017年硕士论文　论文类型：学位论文

【摘要】：低输量运行是指输油管道在低于设计输量的工况下运行,而且我国所产原油多为高含蜡原油。在低输量状态下运行时,管道沿线温降较大,结蜡严重,易造成蜡堵事故的发生,另外,为防止凝管事故发生,需大幅度提升出站温度,能耗增大,高含蜡原油在低输量状态下运行既不安全有不经济。因此需要对高含蜡原油管道低输量状态下的安全经济运行技术进行研究。本文在前人科研成果的基础上,综合考虑高含蜡原油管道低输量运行的热力、水力特性及蜡沉积规律,结合蜡沉积室内环道实验,应用相关向量机算法构建蜡沉积速率预测模型。以大庆油田某输油管道为例与蜡沉积动力学模型及神经网络算法模型的蜡沉积速率预测结果进行对比分析。结果表明,本文所提出的蜡沉积预测模型平均误差为1.27%,均方根误差为0.3,相关系数达到0.921,预测精度高,稳定性好,能够较为准确的描述原油管道实际运行工况中的蜡沉积现象。其次,在理论蜡沉积规律研究及热力、水力特性研究的基础之上,引入区间数方法,对与大庆油田某管道运行安全性有关的各影响参数进行了重要性分析,确定了各影响参数的重要性排序,得到了各影响参数的概率分布。然后,对各影响参数进行抽样,得出了在进站温度一定的条件下所对应的最小安全输量概率分布规律符合正态分布的结论。同时,结合实例给出了计算不同运行输量大于最小允许输量概率的方法,进一步依据管道运行安全性评价标准对大庆油田某原油管道运行的安全性进行了评价,结果显示该输油管道全年各季节运行工况安全等级均≥2,安全性较高。之后,综合考虑最优输油温度,最优输油压力及最优清蜡周期之间的相互耦合,以一定时间内的总输油成本最小为目标,以管道低输量运行的安全性为约束条件,三种经济指标为决策变量,提出了同时求解三种经济指标的安全经济运行优化数学模型,并给出了迭代求解方法。以大庆油田某输油管道为例,计算得到了各经济指标的区间数,通过统计分析得到了各经济指标的概率分布。最后,在此基础上结合之前的重要性分析,首次提出了综合考虑最优出站温度,最优出站压力及最优清蜡周期三种经济指标的管道稳定运行经济指数(SOEI)的概念及计算方法,使得管道稳定运行经济指数(SOEI)可以对高含蜡原油管道在低输量运行时的经济性进行综合评价。以大庆油田某输油管道为例,安全经济性评价结果表明,由于出站温度经济指数较低,管道运行工况在2、8月份时经济性评价指数SOEI等级为3,已偏离运行工况的经济运行区间,应有针对性对出站温度进行相应调节,使其恢复到运行工况的经济区间范围内,并给出了各经济指标的最优的经济运行区间。
[Abstract]:Low throughput operation refers to the pipeline below the design output conditions of operation, but also China's production of crude oil is high wax crude oil. In low flow condition, large temperature drop along the pipeline, wax, wax, easy to cause the blocking accident in order to prevent the occurrence of coagulation the accident of tube, need to greatly enhance the temperature of the station, and increases energy consumption in low flow condition is not safe and not economic wax crude oil containing high. So it is necessary to study the low throughput under the condition of safe and economic operation of high waxy crude oil pipeline. In this paper based on the previous research, comprehensive consideration high waxy crude oil pipeline running of low flux thermal hydraulic characteristics and wax deposition, with wax deposition indoor loop experiment, application of relevance vector machine algorithm to construct prediction model of wax deposition rate. With the dynamic model of wax deposition in Daqing oilfield and pipelines The wax deposition rate prediction model of neural network algorithm were analyzed. The results show that the average error of wax deposition model proposed in this paper is forecast to be 1.27%, the RMS error is 0.3, the correlation coefficient reached 0.921, high accuracy, good stability, can wax deposition in the actual operation condition of phenomenon description of crude oil pipeline accurately. Secondly, in the study of theory and thermal wax deposition, based on the research of the hydraulic characteristics, introduced the interval method, with the parameters of Daqing oilfield pipeline safety operation of each related to the importance of analysis, to determine the importance of each parameter's influence ranking, get the probability distribution of parameters. Then, sampling the effect of each parameter, the minimum output probability distribution with normal distribution of the corresponding conclusion in the same temperature. At the same time, combined with the real Patients given different operation of transmission is greater than the minimum allowable throughput probability method, on the basis of operation safety evaluation safety of pipeline operation standards for Daqing oilfield crude oil pipeline were evaluated. The results show that the oil pipeline in all seasons operating security level greater than or equal to 2, high security. After comprehensive consideration the optimal oil temperature, oil pressure and optimal optimal coupling between the clear wax cycle, in order to minimize the total transportation cost in a certain period of time, with low throughputrunning safety of pipeline operation as constraint conditions, three economic indicators as decision variables, is proposed to simultaneously solve three economic indicators in safe and economic operation optimization the model, and gives the iterative solution method. An oil pipeline in Daqing oilfield as an example, the interval number of each economic index calculation, through statistical analysis of various economic indicators The probability distribution. Finally, combined with the previous analysis of the importance on the basis of this, put forward for the first time considering the optimal temperature of the station, the optimal pipeline stable economic operation index and the optimal pressure pigging period of three economic indicators (SOEI) concept and calculation method, the economic index of pipeline stability (SOEI) can be carried out comprehensive evaluation of economy of high waxy crude oil pipeline oil transportation at low. An oil pipeline in Daqing oilfield as an example, the safety and economy of the evaluation results show that the temperature of the station economic index is low, the pipeline operating conditions in the 2,8 month when the economic evaluation index of SOEI grade 3, has deviated from the operating conditions the range of economic operation, should be targeted to the corresponding adjustment to the temperature of the station, bring it back to the range of operating conditions in the economy, and gives the optimal economic indicators of the economic operation range.

【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】：TE88

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