Study On Adjustment And Optimization Of Surface Gathering And Transferring System In Old Oilfields

With the development of oil fields,China's oil fields have gradually entered a period of extremely high water cuts,and the amount of oil produced and gas production have been continuously reduced,and the water content of produced fluids has increased dramatically.Oil and gas gathering system have problems such as the large number of transferring stations,unbalanced loads,and the mismatch between the original design and actual production,which makes the energy consumption of the gathering and transferring system high,which seriously affects the economic benefits of the oilfield.Therefore,it is necessary to carry out adjustment and optimization research on the old oilfield gathering and transferring system,and on the basis of the optimization of the traditional topological structure,comprehensive consideration shall be given to the withdrawal of existing pipelines and transferring stations.In this paper,the layout structure is firstly studied for simplification and optimization.The article takes the minimum construction cost and operating cost as the objective function,and considers various constraints such as hydraulic constraints,technical constraints and economic constraints to establish the MINLP model.The piecewise linearization method is used to approximate the nonlinear term in the MINLP model and converted into the MILP model.The branch-and-bound algorithm is used to solve the nonlinear term.Through the model optimization results,the adjustment plan of the transferring station and the connection scheme between the transferring station and the testing station can be obtained.Secondly,considering the economy,reliability and production adaptability of the gathering and transferring system,the fuzzy evaluation hierarchy process is used to establish a comprehensive evaluation system and comprehensively evaluate the system.By comparing the evaluation results of the system before and after optimization,the simplified optimization effect of the system topology is tested.In addition,for the newly-built pipelines in the process of layout adjustment,path planning optimization research is conducted,and the risk level is transformed into an obstacle in the study area.The A-star algorithm is used to solve and the optimal path of the pipeline is determined.Finally,a simplified optimization software module for the oilfield gathering and transferring system was developed.The software module was successfully applied to a system and achieved good results.It is of great significance to further guide the adjustment and reconstruction of oilfield gathering and transferring system.