苏嵯输油管道正反输运行工艺优化技术研究

发布时间：2019-06-06 02:19

【摘要】：随呼伦贝尔油田产量递减,承担其原油外输任务的苏嵯输油管道逐渐进入低输量运行阶段,为保证其安全运行,该管道于2013年建立了正反输运行工艺。但由于缺少系统的理论研究,导致该管道正反输工艺方案的制定主要凭人为主观经验,运行过程的安全性和经济性得不到保障。为了保证苏嵯输油管道的安全和经济运行,针对该管道开展了正反输工艺条件下的热力、水力特性及优化运行技术研究。取得的主要成果如下:首先,建立了表征输油管道稳态和非稳态运行过程热力特性的数学模型,采用有限元结合有限差分法进行求解。针对稳态运行工况,采用反算法计算得到苏嵯输油管道全年不同月份的总传热系数,使稳定运行状态下不同管段的温降计算误差降低为2.41%和3.25%,提高了管道的热力计算精度。针对管道反输开始阶段的非稳态运行工况,数值计算得到管道沿线不同管段的“总传热系数”,以此对不同反输时间、反输温度和输量下管道沿线的散热损失和油温变化规律进行了分析,同时以原油凝点以上3度为温度界限,确定了苏嵯输油管道不同工况下的最低反输输量。其次,结合输油管道蜡沉积随时间的变化规律,按运行时间的不同将清管后苏嵯输油管道的运行过程分为四个不同的阶段。针对每个运行阶段,以雷诺数为依据,采用两阶聚类方法将其划分为多个不同的运行工况,以非线性最小二乘估计法回归分析得到不同工况下管道的水力摩阻系数计算模型,最终形成能够全面表征含蜡原油管输过程水力特性的计算模型。与理论模型相比,“首站-中二站”管道清管后不同运行阶段的总压降计算误差由21.64%、17.26%、17.04%、19.53%降低为10.43%、11.99%、14.16%和3.87%。“中二站-末站”管道的总压降计算误差由23.31%、24.27%、27.84%、21.07%降低为6.02%、6.22%、11.98%和4.01%。最后,在对苏嵯输油管道正反输过程水力、热力特性研究基础上,以一定时间内苏嵯输油管道正反输运行过程的总能耗费用最小为目标,以管道安全完成输油任务为约束条件,管道正反输运行时间、输量和运行参数为决策变量,建立了苏嵯输油管道正反输运行工艺方案优化数学模型。实例计算结果表明,通过优化可以使管道正反输过程的运行成本降低12.16%。按照同样的方法优化得到苏嵯输油管道全年不同季节、不同输量下的正反输运行方案,为苏嵯输油管道的安全经济运行提供了有效的技术保障。
[Abstract]:With the decline of production in Hulunbeier Oilfield, the Su-Yu pipeline, which undertakes the task of crude oil transportation, has gradually entered the stage of low transportation volume. In order to ensure its safe operation, the pipeline established a forward and negative transportation operation process in 2013. However, due to the lack of systematic theoretical research, the formulation of the forward and negative pipeline transportation process scheme is mainly based on artificial subjective experience, and the safety and economy of the operation process can not be guaranteed. In order to ensure the safe and economic operation of Su Yi oil pipeline, the thermal and hydraulic characteristics and optimal operation technology of the pipeline under the condition of positive and negative transportation process were studied. The main results are as follows: firstly, a mathematical model is established to characterize the thermal characteristics of oil pipeline in steady and unstable operation, and the finite element method combined with finite difference method is used to solve the problem. According to the steady-state operation condition, the total heat transfer coefficient of Soviet oil pipeline in different months of the year is calculated by inverse algorithm, which reduces the calculation error of temperature drop of different pipe segments to 2.41% and 3.25% under stable operation condition. The thermodynamic calculation accuracy of the pipeline is improved. According to the unstable operating conditions in the initial stage of pipeline reverse transportation, the "total heat transfer coefficient" of different pipe segments along the pipeline is calculated by numerical calculation, so as to calculate the "total heat transfer coefficient" of different reverse transportation time. The heat dissipation loss and oil temperature variation along the pipeline under reverse transportation temperature and transportation volume are analyzed. At the same time, taking the temperature limit above 3 degrees above the freezing point of crude oil as the temperature limit, the minimum reverse transportation capacity of Su-ao oil pipeline under different working conditions is determined. Secondly, according to the change of pipeline wax deposition with time, the operation process of Sui oil pipeline after pipe cleaning is divided into four different stages according to the different operation time. For each operation stage, based on Reynolds number, the two-order clustering method is used to divide it into several different operating conditions, and the nonlinear least square estimation method is used to regression analysis to obtain the calculation model of hydraulic friction coefficient of pipeline under different working conditions. Finally, a calculation model is formed, which can comprehensively characterize the hydraulic characteristics of waxy crude oil pipeline transportation process. Compared with the theoretical model, the calculation error of total pressure drop in different operation stages of "first station-second station" pipeline is from 21.64%, 17.26%, 17.04%, 19.53% to 10.43% and 11.99%, respectively. 14.16% and 3.87%. The calculation error of the total pressure drop of the "second and last station" pipeline decreased from 23.31%, 24.27%, 27.84%, 21.07% to 6.02%, 6.22%, 11.98% and 4.01%, respectively, from 23.31%, 24.27%, 27.84%, 21.07% to 6.02%, 6.22%, 11.98% and 4.01%, respectively. Finally, on the basis of the study of the hydraulic and thermodynamic characteristics of the positive and negative transportation process of the Soviet oil pipeline, the total energy consumption cost of the positive and negative transportation process of the Soviet oil pipeline is taken as the goal, and the safe completion of the oil transportation task of the pipeline is taken as the constraint condition. The operation time, transportation volume and operation parameters of positive and negative pipeline are decision variables, and the mathematical model of forward and negative pipeline operation process is established. The calculation results of an example show that the operation cost of pipeline forward and negative transportation process can be reduced by 12.16% by optimization. According to the same method, the operation scheme of positive and negative transportation of Jiangsu oil pipeline in different seasons and different volume of the year is optimized, which provides an effective technical guarantee for the safe and economic operation of Soviet oil 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】：2016
【分类号】：TE832.3

【相似文献】