(2022029) A Review of Heat-Related ESP Studies

Due to the ESP motor’s inefficiencies, heat is produced when converting power from electrical to shaft power. This generated heat is either transferred to the surroundings (i.e., through the producing fluids) or absorbed by the motor. In the absence of proper cooling, the motor temperature keeps increasing until either the motor fails or it reaches a temperature high enough to transfer the generated heat to its surroundings. According to the Arrhenius rule, equipment life is expected to reduce in half for every 18°C increase. Proper heat transfer not only avoids overheating failures but also improves the system’s reliability. A survey of the open literature was performed to evaluate how the industry approaches the heat transfer problem for ESP motors. The studies were divided into six different categories. A recurrent approach is to enhance temperature ratings of internal components in the motor and perform field trials to verify an increase in reliability. Although this is a sound practice from a commercial point of view, it does not provide any insight. This review recovers simple theoretical models enabling a more fundamental understanding of ESP motor heat transfer behavior in complex scenarios. It also elucidates areas where knowledge is still lacking, particularly in two-phase flow conditions around the motor.