English abstract
Electrical submersible pumps (ESPs) are used in oil production as effective means of artificial lift. The design of ESP components is very special because of its long and slender shape and the stringent operational requirement within the oil well borehole. The requirement of high power ESPs for high capacity wells is pushing the design process even further requiring careful consideration of all major components like the electric motor, the seal, the gas separator and the pump.
A rotordynamic model for an entire electric submersible pump (ESP) typically used in an oil well consisting of the motor, the seal, the intake and the pump sections has been developed using finite element method (FEM) taking into consideration the lateral and torsional dynamics. The stiffness and damping coefficients of the bearings and seals have been estimated based on the dimensions and the operating conditions. The model has been used to study the existing configuration of the ESP and to validate its dynamic behavior under the current operating conditions. The model is next used to simulate the ESP rotor-dynamic behavior under various speeds within the operating range. Critical speed maps, stability analysis, unbalance responses and transients of the system are investigated for evaluating the suitability of the ESP for the intended operation. The effects of different design parameters on the system performance are also examined. The study helps in identifying the operation envelope of the ESP.
