Review of Electrical-Submersible-Pump Surging Correlation and Models

Abstract

Summary Head deterioration observed in electrical submersible pumps (ESPs) under two-phase flow is mild until a sudden performance breakdown is observed in the pump head curve at a certain volumetric gas fraction. This critical condition is termed surging. Consequently, the head that the pump generates with two-phase flow depends on whether the stages operate under conditions before (mild performance deterioration) or after (severe performance deterioration) the surging point. The surging, for engineering purposes, can be predicted by published correlations, but the lack of a theoretical basis is a limiting factor for their application. Mechanistic models seem to be the proper alternative. However, the poor understanding of the physical mechanism that causes the surging hinders the development of such mechanistic models. This paper reviews some of these correlations and mechanistic models by comparing the correlation predictions against experimental data acquired in a closed loop with water and air using a commercial 24-stage ESP. The data cover a wide range of volumetric gas fractions, rotational speeds, and intake pressures. As a consequence of this analysis, a new correlation has been formulated. This correlation predicts the initiation of the surging as a function of rotational speed and fluid properties.