Theoretical Analysis And Experimental Research On Variable Parameter For Stiffness Of Sucker-rod System

As a fine elastic rod string of alternating load in the presence of elastic deformation under the action, how to use this rod deformation, so that the effective plunger stroke pump horse head hanging point of stroke is greater than that obtained effect of certain ultra-stroke, has been engaged in mechanical production engineering technical staff is one of the problems. Theoretical study rod string from the stiffness and the relationship between the pumping parameters to improve system efficiency of pumping wells on the field of energy saving is important.In order to study sucker rod pumping system stiffness parameters and the relationship between the integrated system of rod sucker rod string, string, three liquid column vibration rod system to establish the mathematical model of motion. Solution using the difference method the numerical solution of this mathematical model, using delphi language preparation rod system motion simulation program and verified by actual well data correctness of the program.The preparation of the simulation program using a different stroke, stroke simulation parameters, by comparing the simulation results of system stiffness on the pump rod stroke, rod load change rate, input power and the suspension point of the specific impact of underground system efficiency. Considering the rate of change of suspension point, input power factor and efficiency of underground systems, through multiple simulation analysis of stroke in 12min-1,3m stroke combinations can be achieved when the stiffness is 0.5×1011 obvious super-stroke phenomena, and this combination conventional rod system of relative stiffness, can significantly improve system efficiency.Build the indoor pump test system. Change the stiffness of sucker rod and polished rod pumping, measuring and collecting the effective pump stroke pump and the rod load, rod load to calculate the rate of change and system efficiency, obtained by comparing the stiffness of the pump stroke, rod load the rate of change and the underground system efficiency are investigated. By analyzing the results to find a variety of combinations to improve system efficiency, ultra-stroke-stroke pumping stiffness combined to verify the simulation results.