Review of internal flow characteristics and optimization design of spiral axial flow oil–gas multiphase pumps

The increasing exploitation of offshore oil and gas fields has led to a growing need for oil–gas mixed transportation technology and the associated equipment. Among the various types of multiphase flow pumps, the spiral axial flow oil–gas multiphase pump has become an indispensable component of offshore oil and gas transportation systems owing to its excellent performance in handling gas–liquid two-phase flows. This review provides a detailed exploration of the current research status and development trends of this type of pump, with a particular focus on its application in oil–gas–water multiphase transportation. By analyzing the gas–liquid separation mechanism, bubble dynamics, and flow patterns within the pump, the impact of different structural parameters on pump performance is explored, including key design factors such as the stator blade angle, blade tilt angle, and semi-cone angle. The review also covers the flow characteristics of multiphase pumps under different operating conditions, particularly in terms of gas–liquid separation, bubble motion, and the effects of turbulence. Furthermore, it discusses optimization design methods for multiphase pumps, combining genetic algorithms and computational fluid dynamics simulation techniques, and explores the optimization pathways and technological advancements achieved for pump performance. By summarizing research findings, this review provides valuable insights into the future development of spiral axial flow oil–gas multiphase pumps, and offers a theoretical foundation for improving offshore oil and gas transportation efficiency and safety.