Research On Operating Parameter Intelligent Control Technology Of Beam Pumping Well In Low Permeability Oil Field

As a new energy-saving control technology, motor variable frequency drive technology had been widely used in lots of oil field. At present we adopt this new technology mainly base on field data and experience instead of research on pumping system dynamic simulation theory. Based on the domestic and foreign thesis of sucker rod pumping, a kinematic and mathematic model was developed for the mechanism of beam pumping unit in order to obtain the movement variation of the various components of pumping unit when motor variable frequency drive technology was adopted. A Pumping unit system dynamics simulation model was also developed including an equation to describe crank movement and the other was established to describe down hole sucker rod longitudinal fluctuations, fluctuation equation in differential form was detailed deduced and the above tow highly coupled equation were solved using iterative methods. By comparison with field data, the model has sufficient accuracy. Based on the above, a new pumping unit dynamic operation simulation model when motor variable frequency drive technology was adopted was established by studying the effects of pumping systems for the change of motor speed. The simulation result proved that variation in motor speed within a stroke can significantly improve the operating parameters of pumping unit. In order to satisfy pumping unit operating parameter optimization plan for low permeability oil field, two different frequency optimization design were developed including one was based on dynamic liquid level and the other was established by the principle of minimum rms torque of every each pumping cycle in the paper. Pumping parameter optimization program was designed including optimization objective function and constrains. At the meantime, the design principle, system components and control method of pumping unit automatic control system was detailed discussed in this paper. The field data of pumping unit using motor variable frequency drive technology in Daqing oilfield were analyzed to prove using motor variable frequency drive technology can also significant improve motor condition when the pumping unit is starting. An evaluation report of the application effect of improving the state of pumping unit was discussed, and several impact factors that were related to improvement effect of variable frequency drive were also stated in the paper. At last, the pumping unit operation parameter optimization and control application software was developed according to the above research.