| Based on the domestic and foreign thesises of sucker rod pumping,this paper established a simulation model of surface beam pumping systemincludes the mechanical characteristics of motor, reducer simulationsystem,the movement of pumping unit and polished-rod and thesimulation of downhole pump etc. To determine the accuracy of the waveequation rod displacement boundary conditions, Vector and othermathematical means were applied for establishing four typical Pumpingprecision movement models, which contained traditional beam pumpingunit, double horse head beam pumping unit, rocking beam pumping unitand belt-and-chain driven pumping unit. By analyzing sucker-rod loadcycle changes, a simply downhole dynamometer card was gained, whichwas tested by practical data. Discussion of the acceleration due to gravityeffects on the model of the wave equation, a fast solution of the waveequation is derived by using finite difference method. After establishedthree rod vibration models, which include damped oscillationunconsidered gravity effects, undamped and damped oscillationconsidered gravity effects, the relations of the displacement, vibration andload as time changing were analyzed. Three 3D simulation pictures ofthese relations were obtained by computer. Two kinds of valve simulationmodel were established and the pump fluid flow equations were derivedby applying the changes of load in the end of sucker-rod. Studying theimpact of the various components of the simulation of sucker-rod system,based on the establishment of an integrated oil pumping system which iscoupled with each son system model, a simulation program of sucker-rodmechanics was compiled, and it has been applied in Dagang Oilfield and Qinghai Oilfield. With application of the procedure, the calculatedprecision of dynamometer displacement, the dynamic analysis ofsucker-rod, the surface dynamometer card and downhole card of oil wellsmatched well with the data got from Oilfield.
|
PDF Full Text Request