Validation and Optimization of Heat Transfer in the Electrical Submersible Pump Motor by CFD

Abstract

In oilfield applications, an electrical submersible pumping (ESP) system is placed inside the wellbore to provide the necessary energy to lift the fluids to the surface when the reservoir pressure is not sufficient. The ESP system consists of an electric motor, seal section, rotary gas separator (optional), multistage centrifugal pump, electric power cable, motor controller and transformers. The electric motor is placed on the bottom of the unit, and the production fluids are allowed to pass around the motor in order to cool it. The motor generates heat while operating. Study on the temperature rise inside the motor is important to prevent components from failing due to overheating. The temperature rise inside a motor has not been studied extensively. In this work, the temperature of components inside an electric motor was measured under different loading conditions, fluid viscosity and temperature. After testing, the computational fluid dynamic (CFD) was used to model the temperature heat rise in the same motor under the same conditions. The CFD models were validated by the test data within ± 5% error. Furthermore, the validated CFD model was used to calculate the heat rise for different insulation and bedding materials. These computational results from CFD are used to optimize the design of the electrical motor.