Design challenge of high-speed high-power density motor for advanced electrical submersible pump

Electrical Submersible Pumps (ESP) have been widely used in oil and gas extraction as a reliable and efficient method of artificial lift to enhance flow rate of oil and gas from a well. However, as the world shifts towards a less fossil-fuel based future, the role of ESP will need to evolve in order to continue to play an important role in the transitional period. One key challenge facing ESP technology is the increasing depth of exploitable oil reserves, with many new ones located at depths of 3km-4km. This implies the need for more advanced ESP technology that operates at high-speed and high-power density to generate additional artificial lift while keeping a compact and robust structure. These competing features demand a disciplined design methodology. This paper presents the electromagnetic design considerations of a 150kW permanent magnet (PM) motor driving an advanced centrifugal pump at 10,000rpm through a 90mm tubing. Three motor designs are undertaken, and their performances are compared. The results show all three designs meet the target specifications. However, the most optimal option will be dependent on its adaptability in integrating thermal management on the cable length and the operating voltage.