PMM-PCP system comprising permanent magnet motor-driven submersible progressing cavity pump allows all the benefits of PCP without the safety and abrasion risks associated with a steel rod string to surface. The PMM-PCP system is ideal, where it is desirable to minimize the surface footprint of the well for environmental impact reasons. The system has a proven ability to reduce the number of costly workovers associated with rod or tubing wear. Specific examples save 3 - 5 pull in a system life span saving customers thousands of good costs.
The PMM-PCP opens up the range in which PCP can be applied. This allows operators to take advantage of the efficiency and solids handling ability of the PCP in wells where this technology was not an option due to wellbore geometry. In these challenging conditions, the PMM-PCP system can be the artificial lift of choice to improve economics in projects that proves to be difficult to produce economically. Submersible PCP systems are considered where traditional rod-driven systems are limited by depth or where deviated or crooked wells have caused premature rod/tubing wear as submersible PCP systems have no rods. A major limitation of conventional ESPCP is that it requires running a gearbox that proved to be the most unreliable and costly component in the system. The introduction of a 10 pole PMM, which has specifically been designed to operate at PCP pump speeds between 350- 750 rpm, allows a submersible PCP system to operate with no need for a gearbox. The PMM has a higher electrical efficiency when compared to that of a conventional induction motor.
PMM utilizes powerful rare earth magnets embedded in the rotor, this allows the rotor to rotate at the same speed as the magnetic field produced by the stator making it an asynchronous motor and eliminating slip. PMM has a much higher power density allowing the motor to be shorter than a comparable IM. The PMMs also have the ability to output higher starting torque than a comparable induction motor. PMM-PCP system allows producing deviated wells at lower rates than historically deemed feasible with ESPs.PMM-PCP systems offer improved performance and efficiency in oil wells.