Performance degradation and wearing of Electrical Submersible Pump (ESP) with gas-liquid-solid flow: Experiments and mechanistic modeling

Abstract

Electrical Submersible Pump (ESP), one of the most profitable artificial lift methods in the petroleum industry, is sensitive to flow conditions, especially under solid-particle flow. Compared to the sand produced from the unconsolidated sandstone, the proppant backflow in hydraulic fractured wells is more erosive to ESPs due to its higher hardness and larger diameter. As a result, the pump geometry is jeopardized, and the boosting pressure is affected. Therefore, the sand-water-air tests were conducted in this study to investigate the performance degradation and wearing damage in ESPs. For the first time, a semi-mechanistic model based on Achard law was proposed to predict the abrasion damage in the second flow passage of an ESP. A new mechanistic model was established to predict pump boosting pressure and describe the pump leakage effect under gas-liquid flow conditions. Considering the rotational effect, the leakage flow rate was calculated in three stage seal clearances, skirt ring, balance ring, and inter-stage. The change of the clearance calculated by the proposed abrasion equation agrees well with the experimental measurement. With the original and eroded pump geometries, the predicted ESP two-phase boosting pressure matches the measured pump curves, while the flow pattern transition from bubbly flow to intermittent flow is also captured.