Research On Digital Pumping Unit Energy-saving Control System

As the main source of energy, oil field consumed a large amount of electric energy whileensure energy supply. The pumping unit consumed more than40%electric energy of the oilfield total power consumption. It’s a typical mode of “energy consumption for energy”. Alongwith our country moves forward “energy saving and emission reduction”, how to reduce theenergy consumption of the large number of beam pumping unit has become a problem inneed of solution urgently. Research aimed at pumping unit energy-saving control system hasbecome a hot research field.The main reason causing beam pumping unit excessive consumption is that the mainmotor power is much larger in initial stage of oil pumping when the downhole fluid supply issufficient. As developing time continues, the oil fields gradually into the mid-late periodwhen the downhole fluid supply is shortage, pump efficiency is lower, the phenomenon of“half-pumping” and “empty-pumping” is serious, and the degree of balance is unreasonable,pumping unit and well’s parameter is mismatch, which caused “the horse’s huge capabilitieswasted on a petty cart” phenomenon.Aimed at the phenomenon of “half-pumping” and “empty-pumping”, in this paper, weformulated frequency of stroke’s automatic regulation strategy and intelligent intermissivepumping control strategy according to the indicator diagram area. Aimed at the error injudgement of degree of balance using current method because of which can’t recognizetransient power state in down stroke, we use power method to judge degree of balance inorder to improving accuracy. In this paper, we realized the parameter match of pumping unitand well, greatly reduce energy consumption of beam pumping units.Because of the deficiency in reflecting the underground working conditions usingground indicator diagram, we give the specific method to calculate pump indicator diagramfrom ground indicator diagram, which provide a theoretical basis for pumping unit faultdiagnosis technology based on pump indicator diagram. In order to enchance the paper’spractical guiding significance, we also analysised of19kinds of typical indicator diagramsdetailedly.Firstly, I made a module partition according software and hardware function in the specific implementation process. Secondly, I made detail design and equipment selection foreach modle. Finally, I developed a “digital intelligent pumping unit frequency conversioncontrol cabinet” successfully and finished the algorithms’ design of data acquisition ofground indicator diagram, frequency of stroke’s automatic regulation, intelligent intermissivepumping control, power method to judge degree of balance, the specific method to calculatepump indicator diagram from ground indicator diagram and C language implementation. Atthe same time, I designed the “Remote Terminal Unit (RTU)” cooperated with teammembers.At the end of this article, we debugged and tested the energy-saving control systemcoordinated with the seventh oil production plant of Changqing Oilfield Company indigitization management demonstration area of Changqing Oilfield. In these tests, weacquired the data of frequency of stroke, length of intermissive pumping time, degree ofbalance, power factor, power consumption to exploit one ton oil, active power-saving rate ofsingle well and so on. The test results shown that the project we made was feasible. Finally,the experimental datas showed that the system has an excellent energy saving effect inpremise of stable yield, and we obtained a lot of conclusions with guiding significance toproduction.