Wear and Its Effect on Electrical Submersible Pump ESP Performance Degradation by Sandy Flow: Experiments and Modeling

Abstract

Multi-stage electrical submersible pump (ESP) is a frequently used artificial lift method, especially in high production wells. Severe wear and leakage can be caused by sand production from unconsolidated sandstone and proppant backflow. The loss of boosting ability and system stability under sandy flow condition is hard to be predicted, which not only reduces the production but also causes severe failures. In this study, a closed testing flow loop with a mixed type ESP is constructed to test pump performance and efficiency under water-sand flow. 64 hours total testing time is divided into several short intervals. After each interval test, the deteriorated head and efficiency of ESP with pure water were tested. More head loss was observed under low flow rate region, which is presumably caused by leakage through the secondary flow region. Head curve acquired in the test is compared to other studies to analyze the leakage effect in different regions. A leakage flow map including three different regions is provided. The seals’ ID/OD and clearances were measured after the pump was disassembled. The leakage effect in previous mechanistic ESP performance prediction model is modified based on test results. By using the appropriate geometries, the deteriorated head curve can be calculated. Compared to the test curves, the proposed model agrees well with the head degradation trend. The model can be further improved by adding abrasion and efficiency models with more available data.