| dc.description.abstract | The Electric Submersible Pump (ESP) is used in the oil wells where the reservoir pressure is insufficient to push the fluid to the surface. Conventional ESP consists of a series of centrifugal pumps. However, the improvement of twin screw technology leads to the invention of a type of novel ESP, Electric Submersible Twin Screw Pump (ESTSP). To determine the performance of the ESTSP, multiphase tests have been performed with different working conditions and different working fluids.
In this research, the effect of the pressure rise, Gas Volumetric Fraction (GVF) and pump rotating speed on the behavior of the ESTSP has been studied. The pump was tested with a maximum pressure rise of 1000 psig. Hydraulic oil and water were selected as the working fluid to test the pump. The GVF varies from 0% to 85%. To evaluate the performance of the ESTSP, the pressure and temperature distribution, the flow rate capacity and the power consumption were recorded during the test. The performance of the ESTSP was compared with that of a Colfax pump to investigate the difference between the multistage pump and the one-stage pump.
The performance prediction of multiphase twin screw pumps has been a challenge. A new model is proposed to study the leakage flow in the twin screw pump. Adiabatic compressible flow is assumed in the circumferential clearance. The acceleration of the two-phase flow is taken into account in the new model. The change of Mach number of the leakage flow in the clearance and the possibility of choked flow at the outlet of the clearance will be studied.
To verify the leakage model, experimental data of four different twin screw pumps is used to compare with the prediction by the model. | en |
