Study On The Working Condition Diagnosis Of Screw Pump Well And Optimization And Design Method Of Sucker Rod String

Oil production by screw pump is an advanced oil production technology developed inrecent years, because of its small system size, convenient maintenance and administration andhigh pump efficiency, so it is taken into account increasingly, and is widely deployed and appliedin oil fields. The current status of screw pump, development tendency and producing principle ofscrew pump are summarily introduced in the thesis, and then according to features ofsurface-drived screw pump, the force of sucker rod string, which is used to transmit force, isanalyzed, believing that sucker rod string is impacted by compound load, bearing torque, at thesame time bearing bigger axial direction force, and the calculation methods of different loads aregiven. According to the fourth intensity theory, equal intensity design method of compoundingrod is given, namely, diameter and length of different rods are calculated according to demandand normalization, and then they are checked according to intensity condition.Methods of working condition diagnosis and parameter optimization of screw pump arestudied in order to monitor working condition of screw pump, judge malfunction reasons, tap thepotential of oil well, guarantee equipment security and reliability and efficiency and enhancescientific administration level of screw pump well. Mathematical model for production systemand working rule of sub-system of screw pump is established according to the working principleof screw pump. In the basis of analyzing working rule and flow characteristic of wholeproduction well, and considering field production data, working condition diagnosis method ofscrew pump well is given, and influential factors of working condition are analyzed and theapplication check is done.Sucker rod of surface-drived screw pump system is horizontally deformed in the course oftransmit torque, causing friction between sucker rod and inner-wall of tubing. A quantity ofcentralizers is used to reduce friction loss and elongate working life of sucker rod and tubing.Dynamic model of force of sucker rod in screw pump well is brought forward, and movementequation of sucker rod is established, cross deformation of sucker rod in the course of movementis solved according to capacity method of elasticity stability theory, and appropriate installationposition of centralizer is confirmed and rod deformation is controlled, and the earlyabandonment of tubing and sucker rod is avoid because the friction between rod and inner-wallof tubing is avoided Optimization design software of sucker rod in screw pump well iscomplied according to actual condition of oil field, and design calculation instance is given.