A Comparison of Electric Motors for Electrical Submersible Pumps Used in the Oil and Gas Industry

Where the pressure in oil or gas reservoir is not sufficient, in order to increase the production rate, an artificial lift method is required. There are several methods for obtaining artificial lift, including gas injection and electrical submersible pumps. Electrical submersible pumps are more controllable, offer faster installation, and are more economic than other methods, especially for vertical and deviated wells. Electrical submersible pumps systems consist of several parts, including the pump, an electric motor, cables, and a control board. The electric motor plays an important role in an electrical submersible pumps system, and it must produce high torque under high temperature and high-pressure conditions. For small diameter wells, there is also a constraint on the motor diameter. These harsh conditions and constraints require special motors. In this article, the desired criteria for such a motor for this application are represented; then, a comparison is made among several types of motors, including induction motors and various permanent magnet motors, and the resulting best choices are proposed. (paper)