Research On Flexible Control Intelligent Optimization Technique Of Beam Pumping Unit

Because of the geometry structure simplicity,safety and reliability,the beam pumping unit plays an import role in artificial lift in the oilfield.However,due to the inherent characteristics of the beam pumping unit,the crank rotates at a constant speed under normal conditions.The crank drives sucker rod to do straight reciprocating motion.The suspension velocity is quasi sinusoidal motion.The sucker rod is subjected to unbalanced vibration load and inertia load.This will cause a very serious impact on the sucker rod.The speed distribution of pump plunger is uneven.There is a large speed peak.This will cause low yield and low pump efficiency.To solve above problems,we carry on the research of flexible control intelligent optimization technique of beam pumping unit.Through the motor changes speed in a pump cycle,to improve the pumping frequency and the distribution of speed of the plunger,to improve pump efficiency and increase oil production,to reduce the stress of sucker rod and energy consumption of motor,to reduce the fatigue of the ground transmission system and the whole sucker rod.The optimal driving speed curve of the motor is determined by the Fourier series.The Fouries coefficient is based on the maximization of the oil production.At the same time,it must meet the constraints of the given rod stress and motor torque.We can build motion and dynamics model and dynamic prediction model of the sucker rod string,to calculate oil production and sucker rod stress and motor torqe and so on.Through field test,we can achieve the goal of reducing the load of rod,increasing the oil production,and improving the working conditions of the pump by using the flexiable driving of the beam pumping unit.