Dynamic Parameter Simulation And Operating Optimization Of Surface Driven Screw Pump System

The screw pump oil extraction system has gotten more and more extensiveapplication in the oil field for its advantages, which include simple structure,wide adaptability and remarkable energy saving effect etc. As the matter of fact,these advantages haven't been fully played because of the imperfection ofscrew pump product and the related technology. Along with the generalizationapplication of heavy displacement screw pump, the vibration of the screwpump system becomes the increasingly outstanding problem, so thatresearching on the dynamic characteristics and operation optimization of thescrew pump oil extraction system have significant theoretical actual meaning.The paper improved parts of computing method of the statics parameter onthe basis of mechanics analyzing sucker rod string of screw pump. Consideredthe moment of inertia of the ground drive and transmission system, which isinfluence the torsional vibration of the sucker rod, it improved the torsionalvibration mechanics pattern of the sucker rod and the computing method ofnatural frequency. A new dynamics mathematical model of the screw pump oilextraction system is created, which comprehensive considered the speedfluctuation of the dynamo rotary and the torsional vibration of the sucker rod.Using the finite difference method, it calculates and analyzes the kineticcharacteristics in the process of motor start.Carried on analysis to each pitch point power of system from thestandpoint of the system, it's improved the calculation formula of the systemeffective power, and created the computing method of each pitch point power,system effectiveness and all levels parts of efficiencies systematically. Thesimulation result shows: operating parameter and oil well parameter haveconspicuous effects upon the efficiency of system;optimizing swabbingparameter and keep the reasonable submergence is a effective way ofimproving system effectiveness.Under the condition of assumed that the crude oil mobility-thicknessproduct, transmissibility function mode, make use of measuring point fittingprocess of measuring point to deduce a new oil well productivity predictorequation. Comprehensive considered the influence of the factor(such asfeed-discharge coordination equation, sucker rod natural frequency, oil wellproductivity and sucker rod string strength) upon the efficiency of system, it iscreated the mathematical method of the optimization design, which make thesystem effectiveness be highest. Optimization example indicates: optimizingswabbing parameter is a economic and effective way to improve systemeffectiveness.Using Visual Basic 6.0 to develop " Dynamic parameter simulation andoperating optimization of surface driven screw pump system " computersoftware. Example of application indicated that the software has highlysimulation precision, and can satisfy the request of practical application.