Layout optimization of tree-tree gas pipeline network

With the development of petroleum industry and the exploitation of unconventional gas reservoir, the topological form of surface pipeline network is changing gradually and a tree-tree structure is put forward in gas field. Therefore, optimization of the tree-tree pipeline network becomes urgent and indispensable. In this paper, a comprehensive optimization objective function and constraints is established to allow layout design. In view of the characteristics of the model comprising numerous discrete variables (e.g. location, number, allocation relationship, connection decision variable etc), a hierarchical optimization strategy is proposed to decompose it into three sub-problems. On the basis of the proposed model, an optimization program based on Delaunay triangulation has been presented to solve the non-linear constrained optimization problem which contains connection decision variable between wells in clusters on the constraint condition of path length restriction. Further, the reason of using Delaunay triangulation is analyzed and the optimization process of the essential sub-problem has been illustrated. Moreover, the developed program has been applied to a practical coalbed methane field project. The model and method in this paper is shown to be feasible and effective to solve layout optimization on two-level tree-tree pipeline network.