Design And Experimental Research Of Hydraulically Driven Beam Pumping Unit

With the continuous deeply development in oil and gas field,the old oil field exploitation is becoming much more difficult,machine system energy consumption is high with the low work efficiency.As the main part of system efficiency,the efficiency of the whole machine adopt on the ground is essential,therefore,the optimization and reconstruction of the ground equipment is imperative.As the most important part of ground equipment,beam pumping unit is the most important link that affects the mechanical production efficiency.It is necessary to optimize the traditional beam pumping unit.Among them,the hydraulic driven beam pumping unit will become an important direction because of its stable operation and high working efficiency.Pumping unit is a component of the system,for the characteristics of the work is cyclical,the key parts of hydraulic beam pumping unit,such as hydraulic rod,spinning spindle,will produce the fatigue failure under the action of alternating load in the process of work.The current domestic for these components are generally using the statics analysis,or a simulation with time steps applied load,which does not conform to the method and the actual production operation situation.So the dynamics analysis of key parts for pumping unit and the study of the fatigue properties under the periodic motion is very meaningful.In this paper,the five-type rear crank beam pumping unit produced by Xinjiang oilfield machinery factory was taken as the research object,and the reform designment and optimization study of its hydraulic system were carried out:(1)Use the analytical method to analyze the mechanical principle of the pumping unit,determine the motion characteristics of the structure,analyze the composition of the suspended point load of the pumping unit.Use the balance principle of theoretical mechanics,calculate the theoretical safety coefficient of components and the matching degree of hydraulic system components and the structural designment of the hydraulic part.(2)Establish 3d model based on Proe,determine design parameters,and conduct reasonable simplified modeling.In Solidworks,the rigid body kinematics of the mechanism is analyzed to study the motion characteristics of parts of the mechanism,including the influence of variables such as acceleration of the suspension point,rod displacement and contact force on independent variables such as the load at the suspension point,counterweight and the relative position of the hydraulic rod.(3)Based on the coupled theory,use ANSYS transient dynamics part to analyze the key parts of pumping unit in the coupled dynamics simulation,calculate the shaft,bearing,and the kinetic parameters of hydraulic components,hydraulic lever to prone to injury,rotating shaft and the main bearing stress and strain,stress distribution,stress concentration and cycle change rule,the modal analysis of the key parts.Do the analysis of Fatigue analysist based on the modal analysis results,obtain the research results of the Fatigue life and reliability of the key parts,determine the fatigue damage location of key parts.Calculate hydraulic rod and beam joint mechanics as a result,import to AMESim as the boundary condition of hydraulic rod to do the simulation analysis making it more close to the production condition.On this basis,the testing movement parameters and the parameters of the hydraulic system provides changing rules of modification for hydraulic beam pumping unit simulation analysis.(4)According to production requirements,a 1d simulation model of the pumping unit hydraulic system is established in AMESm and the hydraulic system is built with the piston's travel displacement as the target.At the same time,an auxiliary signal feedback loop is set up to monitor the displacement of the hydraulic lever to achieve the goal of smooth response.In the process of setting up,the energy saving of the whole mechanism and the self-locking function of the mechanism in case of sudden emergency stop were considered.The influence factors of hydraulic variables,such as pump displacement,rod displacement and system response speed,as well as their variation rules were studied.A comparative experiment between the traditional beam pumping unit and the hydraulic driven beam pumping unit was established,and the pumping unit group was tested.A number of data were recorded and the results were compared to analyze the experimental results.The results of this paper provide a reference basis for the transformation and design of the hydraulic driven beam pumping unit,which have a reference significance for improving the service life of the hydraulic structure and reasonably setting prociuction parameters.