Study On Analysis And Optimization Of Submersible Direct Drive Screw Pump System

With the development of green oil fields and the transformation of development methods,the number of high-angle deviated wells and platform wells has increased rapidly.The traditional sucker rod lifting methods such as pumping units are worn seriously.The sucker rodless lifting equipments such as electric submersible pumps are not suitable for the production of low-production wells in China.As a new type of rodless lifting technology,the submersible direct drive screw pump has been rapidly applied.However,there is no systematic optimization and diagnosis method and related software to guide the production,which limits the promotion and application of the submersible direct drive screw pump.In this paper,considering the factors such as stator swelling and temperature,through analysing the operating law of subsurface progressive cavity's torque,efficiency and power,the equipment characteristic curve is established.Based on the principle of supply and discharge coordination,the optimal design method of submersible direct drive screw pump is formed.Aiming at the output and system efficiency,this method achieves the optimization of pump type,speed and pump depth.Considering the interaction between the stator,rotor and well fluid,this paper establishes the calculation model of electric power.By comparing the electrical power curve between theoretical analysis and the measured curve,the fault diagnosis chart is formed,applying the K-means clustering algorithm,this paper realize the intelligent fault identification.A computer program module named “submersible direct drive screw pump optimization design and condition diagnosis system” finally comes out.15 submersible direct drive screw pump wells are optimized in T oilfield.The system efficiency is improved by 2.5% than before.12 submersible direct drive screw pump wells in D Oilfield are diagnosed by condition diagnosing module.The accuracy of this program is up to 90%.Through studying the optimization and diagnosis methods of submersible direct drive screw pump wells,this paper forms the related software,which promotes the popularization and application of this technology in oilfields.