Title:study On The Technology Of Improving The Efficiency Of Mechanical Production In Oil Production Well Site

In the "oil for electricity" well site,mechanical production is the most direct effective,potential and economic means to reduce cost and increase efficiency in cold winter with low oil price.Conventional methods such as changing the characteristics of pumping unit driving motor and working process of mechanical production system are easy to be affected by the change of well conditions,and the engineering applicability is poor,especially the phenomenon of empty pump can not be effectively avoided,which seriously affects the effect of mechanical production.Guided by the problem of empty pumping,this thesis studies a new technology of improving the efficiency of mechanical production in oil production well site.The main research contents and conclusions are as follows.This thesis studies the composition and working principle of the mechanical production system of oil well,analyzes the problems existing in its working process,expounds the necessity of improving the efficiency of mechanical production in oil production well site,points out the defects and shortcomings of the existing methods and control methods of improving the efficiency of mechanical production,and studies the development trend of the technology of improving the efficiency of mechanical production.The definition and theoretical calculation method of mechanical mining system efficiency are studied,which provides the basis for calculation;The system efficiency of the pumping system is divided into the sub efficiency of each unit,the efficiency loss and energy consumption distribution of each unit are analyzed,and the node with large energy loss,the oil well pump,is found out,which makes clear the direction for the energy saving and consumption reduction of the pumping system.The soft sensing method of suspension load of beam pumping unit is studied.The polished rod load of pumping unit is one of the important parameters to analyze the problem of empty pumping and optimize the efficiency of mechanical production system.Aiming at the problems of low accuracy and poor stability of the existing methods for measuring the polished rod load of pumping units,a new soft sensing method for polished rod load by using input electrical parameters is proposed.In this method,firstly,the inclination angle of beam is used to directly replace the crank angle,and a new mathematical model of torque factor of pumping unit is established.Secondly,the relationship among the input electrical parameters of motor,the parameters of four-bar linkage and the load of polished rod of pumping unit is established.Finally,the input electrical parameters of motor are substituted into the calculation,and the bad values and the load of polished rod of pumping unit are eliminated by shawler criterion After further processing and correction with the mean filtering method,the online measurement value of the suspension load is obtained.Finally,the accuracy of the method is verified by simulation.The grey control technology of pumping between oil wells is studied,which combines electric parameters and suspension load.Firstly,the law of liquid level change in low permeability and low production oil wells is studied.Secondly,the principle of detecting air pumping in oil wells based on power integration theory is analyzed.On this basis,the fusion method of air pumping characteristics based on electrical parameters and suspension load is studied,and the grey prediction algorithm is applied to the control of inter well pumping.Finally,the grey control model of inter well pumping based on electrical parameters and suspension load is proposed,Finally,the feasibility of this method is verified by simulation.This thesis studies the technical realization of mechanical production efficiency improvement technology in oil production well site.The overall scheme of intelligent measurement and control system for oil production well site is designed;The hardware design and software flow design of the system core intelligent measurement and control unit are completed.The functions of electrical parameter acquisition,soft sensing of suspension load and grey control of pumping between oil wells are realized respectively.The soft sensing method of polished rod load and the grey control model of inter well pumping based on electrical parameters and polished rod load are verified by experiments.The results of field test in No.1 oil production plant of Changqing Oilfield show that the soft sensing method proposed in this thesis can realize on-line accurate soft sensing of polished rod load with good stability and strong engineering practicability.Taking the measured value of load sensor as the standard,the average relative error of maximum load is 2.34%,and the average relative error of minimum load is 3.87%,It can meet the production requirements of oil field;The proposed grey control algorithm for inter well pumping based on electric parameters and suspension load can dynamically optimize the matching between oil swabbing process and wellbore seepage law,realize the coordination of supply and drainage,and increase the efficiency of mechanical production system by 2.73%on average.It can effectively reduce the waste of electric energy,improve the efficiency of mechanical production system,and has high engineering practical value.