Optimal Design For Eccentricity Flexible Pumping Units

The sucker rod pumping technology is in dominant status among all artificiallifting methods, however, the national requirements of energy saving and rational useof resources can’t be met because the problems of the beam pumping units have notresolved well owing to the irrational structure. Aiming at the problem of beampumping units, the principle of eccentric balance is researched deeply based on theflexible plunger pumping system from the perspective of how to achieve positivetorque to complete the study of eccentricity flexible pumping units, pumping systemefficiency is improved effectively to meet the requirements of the oil extraction crafton safety, environment protection and energy saving, and there is great significance topromote the development of the rod pumping technology.The related technology of new type energy saving pumping units is researchedbased on the analysis of technology characteristic of the existing pumping units. Thekinematic and dynamic model of conventional beam pumping unit, double horse headpumping unit, chain pumping unit and multi-well pumping center are established forlaying the foundation to realize the simulation study of the sucker rod pumpingsystem. The application scope, the advantages and disadvantages of the energy-savingare evaluated through the deep study on energy-saving theory of new type pumpingunits to compare with conventional pumping units on its energy saving effect.The eccentric equilibrium structure is proposed and the eccentric flexiblepumping unit is researched through the analysis on the balance and in-depthdiscussion on the torque curve of the pumping units. According to its structuralcharacteristics, the suspension point displacement, velocity, acceleration, torque andpower calculation model are established to analyze the motion law of the suspensionpoint and dynamics characteristics, the alternating amplitude of the net torque isuniform and remains within the positive range, the required reducer torque and motorpower are smaller, therefore the negative torque, big fluctuation and poor workingconditions of reducer and low motor utilization are resolved. The finite element models of key carrying components of eccentric flexiblepumping units are created by using Solidworks software to carry the finite elementstatics analysis in the maximum load conditions of design conditions. Theequivalent cloud images of stress, displacement and strain are analyzed, and theintensity is checked, the results shows that the factor of safety meets the engineeringrequirements to ensure that the pumping units operate safely and stable.The optimization design software of eccentric flexible pumping realizing theoptimization algorithm of random direction is programmed by Using of the MicrosoftVC6.0, the pumping unit and well parameters database are established to optimizesize of the eccentric flexible pumping unit aiming at the different well workconditions. Results before and after optimization were compared, and the optimizedmaximum acceleration of suspension point reduced by15.6%, peak torque decreasedby15.7%,18.5%reduction in root mean square torque, better dynamic performance,making the pumping unit more energy saving.The system efficiency of sucker rod pumping system is studied. Subsystemefficiency models are established by analyzing system efficiency composition. Factorsaffecting the system efficiency are analyzed, including ground-efficiency factors andunderground efficiency impact factors. Supporting technology which consists ofhydraulic self-sealing plunger pump, rope coiled rod and hydraulic self-sealing elasticwellhead is studied, system efficiency is increased by improving the inefficiency onesin the eccentric flexible pumping system.On the basis of theoretical studies, a prototype was made. The correctness andreliability of the eccentric equilibrium theory is verified through laboratory and fieldtest data. The indoor tests prove that the design principle of eccentric flexiblepumping unit is correct and feasible. And field application data show that the pumpingunit achieves positive torque, and reduces the installed power, and have a remarkableenergy saving effect, low power consumption, high efficiency.