Partial discharge and partial discharge testing for ESP motors

Oil recovery in subsea and other applications with high intervention costs are becoming more common. These wells require downhole equipment to have a high level of reliability. Oil companies subsequently are continually searching for further means of testing prior to downhole deployment. This paper is a review of issues related to testing of one segment of downhole production equipment, electrical submersible pumping (ESP) motors. The particular testing reviewed in this paper is partial discharge (PD) testing. ESP motors operate in a pressure range that minimizes the risk of partial discharge-initiated failures, yet many ESP customers ask for partial discharge testing. Understanding partial discharge and how it affects ESP motors is important to understanding when and where PD testing is proper for a particular application. This paper is a review of issues related to partial discharge and testing for partial discharge in electrical submersible pumping motors.