Analysis of Two-Phase Flow Through an Electric Submersible Pump Using Computational Fluid Dynamics

Abstract

Electrical submersible pumps (ESP) are widely used in the oil and gas industry as a method of artificial lift. They typically consist of multiple centrifugal pump stages that convert kinetic energy to hydraulic pressure head. ESPs frequently handle multi-phase flow including traces of gas which degrade their performance. Hence, it is essential to understand how two-phase flow affects the pump performance in order to design and size ESPs. The purpose of this project is to study two-phase flow inside an ESP with air and water as the two fluids using ANSYS Fluent. The pump is simulated at two speeds, namely 3600 rpm and 6000 rpm for fixed bubble sizes at different gas flow rates. The parameters monitored are pressure head, water velocity and air volume fraction distribution inside the pump. They are compared with results from population balance model that simulates the breakup and coalescence of bubbles. At low air volume fractions and high turbulence, bubbles of large size are not likely to exist in a flow and a fixed bubble size simulation gives good results for such a case, as is also verified from previous experimental studies. The data from this project establishes a baseline for future analyses and improves the understanding of effects of bubble sizes for multi-phase flow through an ESP.