The dynamic prediction and optimization of side stream reducing load pump for lift system

Using the Gibbs equation to describe the mechanical behavior of slender rod in this paper,considering the change of its material quality and the influence of rod collar,and based on the rule of suspension point of chain pumping unit and working character of side stream reducing load pump,the upper and lower boundary condition of axial vibration rod string is got and the model of dynamic prediction of ultra-deep pumping system is establish.The result of example calculation shows that predicting indicator diagram is ex-tremely identical with the measured value.The errors of predicting maximum and minimum loads of suspension point are respectively 2.7% and 2.2%.The strength check of rod strings is following finished and the rod string is designed again.As a result,the maximum load of suspension point falls by 26.8% and lifting efficiency rises 15.3%.All of these provide a dynamic prediction method for the system of ultra-deep pumping well.