Design And Development Of Intelligent Controller For Beam Pumping Unit

Beam pumping unit,as the main oil production equipment,is widely used in major oil fields at home and abroad.However,in the process of oil production,the working condition of the beam pumping unit is complex and changeable,and the load fluctuates violently,which leads to the long-term light load operation of the motor,resulting in low system efficiency,serious energy consumption and other problems.Especially when the oil well is short of liquid supply,the excess swabbing capacity will reduce the fullness of the pump,resulting in different degrees of "pump empty" or "dry pumping" phenomenon,further increasing the energy loss.Therefore,it is of great significance to study the adaptive control method of oil well economic operation combined with oil well conditions to ensure the continuous and efficient operation of oil well.Aiming at the problems of low system efficiency and serious energy consumption when the supply and discharge of oil wells do not match,this paper analyzes the load characteristics of beam pumping unit and the principle of variable frequency speed regulation,and puts forward a self-adaptive optimal control model of stroke number and stroke speed based on pump fullness and energy consumption.The system collects the production parameters of the pumping unit in real time,analyzes the working conditions of the oil well,determines the operation times of the oil well,changes the operation state of the pumping unit,and realizes the adaptive variable speed operation of the system.At the same time,aiming at the characteristics of low impact well,the system designs three operation modes,namely frequency conversion constant speed,up-down asymmetry and power follow-up,to realize the flexible operation of oil well and improve the control performance of the system without changing the impact.Due to the strong nonlinear and uncertain load disturbance of beam pumping unit,it is difficult to establish an accurate mathematical control model.Therefore,after analyzing the liquid production and system efficiency of oil wells under different strokes,this paper proposes an adaptive control strategy to maintain a certain pump fullness,and establishes a solution model of pump fullness based on indicator diagram.Then,the software and hardware of the control system are designed respectively.Taking PLC as the core processor,the signal is collected by proximity switch,load sensor and electrical parameter acquisition module.According to the operating conditions of the oil well,the frequency converter is controlled and the motor speed is adjusted to form a closed-loop adaptive control system to realize the intelligent control of the beam pumping unit.After completing the design of software and hardware of the system,the software and hardware of the system are built in the oilfield.Then,flexible start-up test,flexible operation test and supply discharge matching test are carried out in different oil wells respectively.By comparing the experimental data before and after the intelligent control,it is found that the pump filling degree of the system is always in a reasonable range after the intelligent optimization control of oil wells,and the system efficiency is improved.The experimental results show that the system achieves the goal of reducing cost and improving efficiency,and has a certain reference value.