Research On Pumping Unit Energy-saving Technology Combination And Variable-speed Operation

A variety of pumping energy-saving technologies are researched in this paper, which includes balancing character of conventional beam pumping unit and the energy conservation principle, permanent magnet synchronous motor, high slip motor, dual power motor, star-delta converter power-saving box, voltage regulation power-saving box, overrunning clutch, and the frequency control technology for realizing the variable speed operation during the up and down stroke of pumping unit. Normally, various energy-saving technologies are combined used in the oilfield production. According to the characteristic, the mathematical model of the energy consumption and efficiency calculation for oil pumping system is established in this paper. This model contains the motion law and load of the suspension center, the torque on the crankshaft, the energy consumption system and efficiency of the pumping system. The software which used for the energy-saving technologies combination and the variable speed operation calculation is developed by MATLAB. Then, the prediction calculation of the indicator diagram and input power for three oilfield production wells are taken through the developed software. Through the comparison of the calculation results and the test data, the error of mathematical model is verified in a reasonable range.The calculation of system efficiency and M tons liquid power consumption for the 66 kinds of energy saving technologies about "pumping+motor+control+clutch" are carried out by the software. The energy-saving effects of different combinations are analyzed comparatively, and the result shows that the M tons liquid power consumption and system efficiency cannot be better with more combination of the energy-saving technologies. The calculation results show that the combination of "pumping+motor+control (overrunning clutch)"can also achieve the same effect as the combination of "pumping+motor+control +overrunning clutch". Meanwhile, the variable speed operation method is also researched for the up and down stroke of pumping unit. The optimal range of the speed rate for up and down stroke is given through calculating the site wells by the software under different parameters conditions. The results provide a theoretical base for the energy-saving technology combination and variable parameter operation in the process of pumping well production application.