考虑三维地形及障碍的煤层气田集输系统布局优化

Layout optimization of gathering systems in CBM fields considering three dimensional terrains and obstacles

何国玺;  梁永图;  方利民;  任玉鸿;  肖俏

中国石油大学(北京)油气管道输送安全国家工程实验室/石油工程教育部重点实验室/城市油气输配技术北京市重点实验室

HE Guoxi;  LIANG Yongtu;  FANG Limin;  REN Yuhong;  XIAO Qiao

National Engineering Laboratory for Pipeline Safety/MOE Key Laboratory of Petroleum Engineering/Beijing Key Laboratory of Urban Oil and Gas Distribution Technology, China University of Petroleum(Beijing)

煤层气; 集输系统; 三维地形; 障碍; 枝状; 放射状

coalbed methane; gathering systems; three dimensional terrains; obstacles; dendritic; radial

随着煤层气田的滚动开发,集输管网复杂程度急剧增长,管网设计过程中需要考虑环境因素及可靠性,地形起伏和障碍等的存在会影响整个管网系统的管道走向、站位选择。结合"多点接入、柔性集输"和"枝上枝"集输工艺特点,研究煤层气集输管网系统在三维地形且存在障碍情况下的优化并计算优化管网的可靠度。利用3次B样条曲线插值和障碍函数叠加的方法对地形仿真,以管网系统的经济性为目标函数,以相关集输条件为约束,讨论枝状和放射状两种管网连接方式,对连接方式交叉后的4种管网布局模式的经济性进行对比,并将管网可靠性分析转化为树型网络可靠度问题进行求解。结果表明:三维地形下的绕障路径优化既可以减少距离,又可以降低路径的起伏程度,与二维平面上的绕障路径只会使距离增加有本质区别;枝状管网经济性好,放射状管网可靠度高,以总花费与可靠度比值为评价指标,"放射状+枝状"集输管网布局最优;与原模式相比,优化后的"枝状+枝状"与"放射状+枝状"集输管网布局建设投资费用均可减少约30%,且前者管网总长度比后者短约29%,验证了模型的合理性和先进性。

With the progressive development of CBM fields, the complexity of pipeline networks is increasing dramatically. The design of pipeline network should take environmental factors and reliability into account, since pipeline direction and site selection may be influenced by the terrain reflief and obstacles. In this paper, the optimization of CBM pipeline network was discussed under the conditions of three dimensional terrain with obstacles, depending on the features of "multipoint connection, flexible gathering" and "multiple branches" technologies, and the reliablity of the optimized pipeline network was calculated. Terrains were simulated by means of cubic B spline curve interpolation and obstacle function superposition. The dendritic and radial network connection modes were discussed with the economy of pipeline networks as the objective function and the related gathering conditions as the constraints. Then, four pipeline network layout modes which were established by crossing the two connection modes were compared for their economic feasibility. The reliability of pipeline network was solved after being converted into the reliability of tree network. It is shown that the optimized obstacleavoiding path in three dimensional terrain can shorten the distance, and also reduce the relief of the path, which is essentially different from the obstacle-avoiding path in two dimensional plane that could only increase the distance. The dendritic connection mode is the best in economic feasibility, the radial connection mode is the best in reliablity, and the "radial+dendritic" mode is the best when the ratio of total cost to reliability is taken as an evaluation indicator. Compared with the original modes, the optimized "dendritic+dendritic" mode and "radial+dendritic" mode both are 30% less in construction cost and "dendritic+dendritic" mode is about 29% longer than "radial+dendritic" mode in total pipeline length, verifying the rationality and advantage of the model.