Research On Multi-parameter Measurement Technology Of Electric Submersible Pump

Electric submersible pump is a very important oil production equipment under the oil well,and the monitoring system matching with it is an important means to master the downhole production performance,which is of great significance to improve the production efficiency,reduce the production cost and realize the intelligence of oil production.In this paper,the working condition monitoring system of electric submersible pump is studied comprehensively.The system includes two parts: surface equipment and downhole equipment.Downhole equipment mainly includes all kinds of sensors and signal transmitting circuit,the physical quantities such as intake temperature,intake pressure,discharge pressure,motor winding temperature,vibration,and the water content of fluid in the wellbore will be converted into current signal and transmitted to the ground by using time-sharing method.After transmission with the above physical quantities correspond to the current signals,the downhole equipment also uploads a reference current signal which can calibrate the previously uploaded current signals.The surface equipment is mainly composed by MCU,STM32 and peripheral function circuit.It can analyze and process the current signal uploaded underground,and realize the real-time display,storage,transmission and alarm functions of the monitoring data.The power supply of the system is based on the principle of Y point equipotential,which provides +60V DC power source from surface to downhole.The current signal transmission is based on the multiplexing system of power supply and signal transmission.The current signals are transmitted to the surface through the outer armor of the power cable of the submersible motor.The surface and downhole filter circuits can prevent the common mode voltage at the Y points of the three-phase reactor and the Y points of the motor winding from causing damage to the surface and downhole circuits.The effectiveness of the downhole and surface filter circuits and the feasibility of the way of system power supply are verified through simulation experiments.Through sensor experiment,the fitting function relation between the physical quantity of each monitoring parameter and the current signal is obtained,which provides a theoretical basis for the MCU to restore the physical quantity of each monitoring parameter through the current signal.The value of the reference current is determined by the experiment of the reference current,which provides a theoretical basis for the error elimination of the system.Through the joint adjustment experiment,it is verified that the electric submersible pump working condition monitoring system developed in this project can realize the real-time monitoring of the electric submersible pump's working condition,and can make it work stably for a long time.Through various monitoring data,it can also help crude oil production enterprises to realize energy saving,consumption reduction and digital management of oil fields.