Electric Submersible Plunger Pump Optimized Design And Diagnosis

With the increasing number of high inclined wells and horizontal wells in China,the serious problem of eccentric wear of rod string in traditional beam sucker rod pumping system is becoming more and more serious.As an important new type of rodless lifting equipment,ESPP has good application prospects.However,with the wide application of ESPP system in petroleum exploitation,many problems such as low system efficiency,numerous faults and difficult to diagnose are becoming more and more serious.In the actual production process,there is a lack of a systematic optimization diagnosis method and related software to guide production,which limits the popularization and application of ESPP.In this paper,the structure and basic principle of ESPP are briefly introduced.Aiming at system efficiency,the optimization design model of ESPP wells is established.The parameters of ESPP wells,such as pump diameter,stroke,pump depth and linear motor type,are optimized,and the system efficiency of ESPP wells is improved.Various common working conditions of ESPP wells are studied,their causes and pressure variation in the pump are analyzed,and simulation dynamometer diagrams under different working conditions are obtained.Motion law and power variation law of linear motor are studied.A model for solving downhole pump dynamometer diagrams based on input power is established.Fault diagnosis is realized by comparing with simulation dynamometer diagrams.Through theoretical research,the software for optimum design and condition diagnosis of ESPP system is compiled.After optimizing the design of 10 ESPP wells in a production plant of S oilfield,the system efficiency increased by 6.28 percentage points on average.The working conditions of 8 ESPP wells with possible faults were analyzed and diagnosed,and the accuracy rate was 75%.This paper studies the optimization design and diagnosis method of ESPP wells,and forms corresponding software,which promotes the popularization and application of this lifting technology in oilfields.