Failure Analysis of Seal Lock Plates in Electric Submersible Pumps

Electric submersible pumps (ESPs) are used in oil production as effective means of artificial lift. All the major componets of an ESP are put in a long and slender housing. Seal section, located between the motor and the pump, consists of a number of chambers. All the chambers, the base and the head of the seal are connected to the ESP housing through threaded joints between the seal guide and the housing. Lock plates are welded to the housing over each threaded connection to provide additional constraint. The paper presents experimental results to examine different configuration options for lock plates on a type of high power ESP seal housing failed during operation. The paper summarizes the results of mechanical and metallurgical tests, mechanical strength and vibration analyses along with appropriate recommendations. This paper brings into focus the importance and necessity of analyzing even relatively simple and minor components like seal lock plates for safe operation of ESPs.