Research and Evaluation of Variable Speed Optimization Operation Technologies for Pumping Unit in Y Oilfield

In order to solve the problems of poor balance, high system energy consumption and low efficiency for operation of conventional pumping units, several variable speed optimization operation technologies have been studied and applied in Y oilfield. Through the research of variable speed kinematic model of pumping unit, based on the saddle-shaped law of ‘large load deceleration, small load acceleration’, the balanced power operation mode is formed. Through the system dynamics analysis under different operating parameters, the combined optimization mode of crank continuous rotation and crank swing is formed. According to the optimization demand of variable speed within a single cycle of oil well, the segmented speed regulating operation mode is formed. Field test results have shown that the spike power of the power curve of the pumping unit is decreased by 56.0% and the spike torque is decreased by 3.3%, and the vibration of the pumping unit is decreased obviously for the balanced power operation. The spike power of the crank shaft is decreased by 77.6% and the spike torque of the crank shaft is decreased by 66.5% for the crank swing operation. The spike value of active power is increased by 39.6%, the spike value of crank shaft torque increases by 10.5%, and the maximum load of suspension point increases, and the vibration amplitude of pumping unit increases for the segmented speed regulating operation, All the field test would provide important technical guidance for the optimization of variable speed operation and energy saving of pumping unit.