Comparison of Multiphase Pumping Technologies for Subsea and Downhole Applications

Abstract

Abstract The selection criteria for multiphase boosting options remain somewhat subjective and frequently influenced by the vendors’ data, which may mask potential limitations of this emerging technology. Existing literature on multiphase pumping tends to focus on a certain pump type for a specific field application, but does not provide more generalized criteria for the selection of multiphase boosting solutions from among those available in the market. A comprehensive literature review into the working principles of the major pump types identified the intrinsic advantages and limitations of each technology for subsea and downhole applications. The survey showed that, for subsea application, both the twin-screw pump (TSP) and the helico-axial pump (HAP) can handle high suction gas volume fraction (GVF) with a fluid recycling system, or flow mixer. Thus, GVF is not a discriminating factor. The positive displacement principle allows TSPs to work with very low suction pressure, but limits their operating range because of the dependency of flowrate on their relatively low speed. However, these pumps can handle highly viscous fluid. The roto-dynamic concept enables the differential pressure of HAPs to self-adjust to any instantaneous change in suction GVF, and to achieve higher flowrate if sufficient suction pressure is maintained. As HAPs usually run at higher speed, they offer a wider operating range. For subsea application, HAPs appear to be a better option than TSPs, because they offer higher operation flexibility and have a better installation track record. For downhole applications, the electric submersible pump (ESP) and the progressing cavity pump (PCP) are the outstanding favorites, with the latter being preferred for lifting streams that are viscous or with high sand content. For GVF up to 70%, the roto-dynamic pump (RDP) is becoming a popular solution. Although it is claimed that the downhole twin-screw pump (DTSP) can handle up to 98% GVF, it is not yet widely accepted in the field.