Optimization design method of multi-stage multiphase pump based on Oseen vortex

Abstract The multiphase pump is a vital equipment for exploitation of oil-gas resources on offshore platform. Multi-stage structure is essential for multiphase pump to obtain required head. In present study, a novel method is proposed to optimize performance of multi-stage multiphase pump by theoretical prediction based on Oseen vortex. The velocity moment of flow field downstream diffuser can be predicted according to established theoretical model, and it is applied to optimize inlet blade angle of next impeller. In order to validate the proposed optimization method, case study has been done on a three-stage multiphase pump. The velocity moment is accurately predicted by theoretical model based on Oseen vortex, with average deviation of 6.45%. Applying proposed optimization method, the pump head and efficiency can be improved by 0.29% and 0.19% in average, respectively.