Design And Optimization Of Pressurization Scheme For Oilfield Water Injection Underinjection Well Cluster

Injection flooding is an effective way to maintain efficient production in oilfields.However,in the same set of injection pipe network,due to the different distribution of injection Wells and the different formation structure and properties of injection water,the injection pressure varies greatly.In order to ensure that all injection Wells can meet the injection distribution requirements,the system pressure must be greater than or equal to the pressure of the few Wells with the highest injection pressure.However,for most low.pressure Wells in the system,the pressure provided by the system is far greater than the pressure required for normal operation,and the pressure needs to be adjusted by adjusting the wellhead valve of the injection well,so there is a high loss of wellhead throttling energy consumption.In addition,in the long.term operation under high pressure conditions,the leakage phenomenon of the pipe network system and the cost of safety maintenance will increase,and the probability of pipe network failure will also increase.Therefore,it is necessary to carry out the overall depressurization transformation of the water injection system and implement partial pressure water injection.On the basis of ensuring the water injection demand of a few high pressure Wells,Reduce the operating pressure of the whole water injection pipe network to achieve energy saving,improve system efficiency and improve the operation safety of the pipe network.Based on the investigation of the relevant oil field production units,and on the basis of fully demonstrating the formation reasons and solutions of under-injection Wells,the solution of using partial pressure and partial injection is put forward: to separately boost and inject water into high-pressure under-injection Wells,and to depressurize most low-pressure well patterns.Combined with relevant theoretical knowledge,this paper demonstrates the superiority and feasibility of pressurized water injection,introduces the common basic mode of pressurized water injection in detail,and carries out the pressurized water injection design in the underinjection well area: According to the geographical distribution characteristics of underinjection Wells,a reasonable booster model is selected,the location and number of booster stations are obtained by using clustering algorithm,and the topological relationship of well stations is optimized according to the shortest weighted distance of pipeline laying.Then the design scale of booster stations is determined.Finally,each booster station is connected to the main line of water injection pipe network based on the principle of shortest connecting pipelines,thus completing the preliminary design of booster water injection.The main influencing factors of operation energy consumption are analyzed,and the pipe diameter and the minimum booster head of the booster station are optimized,and then the booster water injection design scheme is optimized.The pressurized water injection system is part of the overall water injection system.In order to achieve the optimal reduction in energy consumption of the injection water injection system,the injection water station in the low pressure area is adjusted accordingly.After long-term operation,the relevant parameters of the injection water station are different from the original parameters,and the parameters of the pump characteristic curve are corrected by using big production data.To achieve the optimization of each injection pump displacement with the goal of minimum single consumption;Draw the characteristic curve of the water injection station and select the appropriate pumping mode according to the total injection flow.Using Python language to write the optimal design program of the pressurization scheme of the underinjection well group,and using the program to analyze the example of the ordinary water injection system,the results show that the implementation of pressurization water injection can effectively improve the efficiency of the water injection system with underinjection well group and reduce the water injection per unit consumption.