Research On Optimization Technology Of Pump Combination In Oilfield Water Injection Pumping Station

Water injection is often used to help increase production of oil in oilfield.Because of the huge amount of water injected into the well every day,water injection accounts for a great proportion of energy utilization in oilfield.As the power source of water injection system,the operation efficiency of pumping station directly affects the energy consumption of water injection system and even the whole oilfield production.The pump is the core equipment of pumping station and its combination and parameters of operating affect the operation efficiency of the pumping station.In order to improve operating efficiency of water injection,the optimization algorithm of centrifugal pump series-parallel combination and reciprocating pump parallel combination are established respectively,with the lowest energy consumption as the objective function,considering centrifugal pump and reciprocating pump in pumping station in this paper.Pump station optimizing module of the optimized software of pump and pipeline network of water injection surface system is compiled,which provides suggestions for optimum operation of pumps.The characteristic curve of pump is the basic data in the operating optimization process.This paper analyses the actual characteristics of water injection pump,obtained its fitting formula by least square fitting method,and converted the theoretical characteristics to the actual characteristics according to the liquid characteristics used in water injection and oil production.In addition,the characteristics of series-parallel combination of centrifugal pump and parallel combination of reciprocating pump are analyzed,and the mathematical method of its high efficiency zone is established.At present,the research on the optimization of pumping stations is relatively single,which means that the parameters of the optimizing only include the start-stop of pumps and the series-parallel combination of pumps.In view of this,this paper studies the series-parallel high efficiency zone under the speed regulation of centrifugal pump,and establishes the optimization algorithm of series-parallel combination of centrifugal pump.By solving the optimization algorithm,the combination of centrifugal pump with the lowest energy consumption and its parameters of operating can be obtained.In addition,this paper also studies the parallel high efficiency area under the speed regulation of reciprocating pumps,and establishes the optimization model of parallel combination of reciprocating pumps.By solving the optimization algorithm,the combination of reciprocating pumps with the lowest energy consumption and its operation parameters can be obtained.At present,there are many factors to be considered when optimizing the pumping station,which makes the optimizing prccess inconsistient with the actual situation.In this paper,based on the known data of pump's outlet,the operation optimization of pumping station is studied separately based on pump combination optimization.With the lowest cost as the objective function,the operation optimization method of pumping station is obtained,and its solving process is given.