Permanent Magnet Synchronous Motors (PMSM) Are Powering Many Oilfield Operations, Mostly Production, but Also Drilling and Pipeline Transport

      Permanent magnet synchronous motors (PMSMs), also known as just permanent magnet motors (PMMs), are becoming more common in the oil & gas industry, especially for well production and artificial lift. Induction motors are the main type of motors used in oil & gas, but PMMs are replacing them in several areas.  Induction motors require current to be sent to the motor, but PMMs do not. Instead, the permanent magnets are mounted on the motors, which leads to increased efficiency through reduced power losses and higher power density. These motors can drive pumps, compressors, and other equipment. PMMs are typically used to power electric submersible pump (ESP) systems. According to UK PMM manufacturer Enneng:

“The adoption of PMSMs in the oil and gas industry marks one of the major recent technology shifts toward higher-value, more sustainable motor technologies. With inherent high torque density, precision speed control, and low maintenance requirements, PMSM motors are aptly suited to power critical equipment during oil exploration, extraction, and transportation.”

     The main advantages of PMMs over induction motors are improved reliability, increased well production, and improved efficiency. Improved efficiency means less energy use, lower operational costs, and lower emissions. PMMs have fewer moving parts than induction motors and lower maintenance requirements. Less maintenance means less downtime. They are better at operating at variable speeds. This means they are better at pump speed adjustments against flow rate variations in oil recovery. Enneng notes:

“Further integration with PMSM using advanced control algorithms and monitoring systems enhances the reliability of the latter during the operation in oilfield applications. Real-time monitoring and diagnostics permit quick detection of developing problems, allowing proactive measures in respect to maintenance. Thus, finding the problem well in advance and rectifying it will also improve the reliability of PMSM and overall operational efficiency in an oil field activity.”

     PMMs offer precise control of speed and torque. They are also resistant to vibrations, temperature, and corrosion. These abilities make them superior to induction motors. According to motor manufacturer Horizon Technology

“A 50 kW (about 70 HP) permanent motor typically weighs less than 30 lbs. At any given frequency, the rotational speed of the permanent magnet motor is always greater than that of its induction counterpart due to the inherent slippage necessary in the induction design.”

     According to a recent webcast on PMMs by World Oil, there are 1100 PMMs installed globally, with over 200 installed in the Permian Basin. The webcast was conducted by Baker Hughes personnel and highlights Baker Hughes’ Magnefficient PMMs. These are offered in several different horsepower (HP) versions. These motors are smaller than similar HP induction motors. On average, they are 30-50% shorter. This means they can be set deeper in wellbores. The smaller size makes them more applicable for slim holes. They also eliminate the need for tandem connections that larger induction motors have when adding HP. PMMs are easier to set up than IMs. They have also shown a 10% increase in uptime over IMs. They have been shown to be more stable in gas slugging events. Peak power usage is also lower, putting less stress on the power system. Pressure drawdown in wells also improved slightly. They are also more stable at lower loads. Power consumption is decreased by 15-30% on average. They have a broader optimal capacity range. They can reduce Scope 2 emissions. A Baker Hughes Magnefficient PMM is shown below with a list of advantages. Below that is a PMM made by SLB.

Source: SLB

     In the Permian installations, there have been no safety issues and no motor failures. Ops are moving from pilot to full commercialization in the Permian. Drive integration is important. Baker Hughes has their own drives, variable speed drives (VSDs), which are the most compatible with their PMMs, but they can be integrated with third-party drives. PMMs are currently up to 1200 HP, but new models up to 2000-3000 HP are in the works, mainly for geothermal applications.

     Electrical safety is an important issue. The use of the right PPE and proper training is emphasized. Determining the presence or absence of current during installation is important. Preventing the pump from spinning the motor during installation is important. Testing includes a 1) Power Generation Curve, which evaluates efficiency, 2) Fast Varying Load Test - determines how a PMM reacts to load changes, 3) High Load Start Test – simulates and ensures that required torque is correct, and 4) Grounded Leg Test makes sure it operates with a grounded leg. Baker Hughes offers in-house training for PMM installation.

     Well production increases of 10-12% have been shown with PMMs. Some is due to psi drawdown. One questioner asked why the adoption rate was so low. They answered that it is starting to grow faster. There is some distrust of electric motors. Results of studies showing improvements with PMM installations are just coming in. Training and safety requirements slow down adoption rates. The rate of adoption has grown faster globally than in the U.S., but that is likely to change as the benefits are more widely confirmed.

  

 

References:

 

Permanent Magnet Synchronous Motors for Oilfield Applications. Enneng. December 22, 2023. Permanent Magnet Synchronous Motors for Oilfield Applications

Induction vs. Permanent Magnet Motor Efficiency | Electrification. Fran Hanejko. Horizon Technology. November 29, 2022. Permanent Magnet vs Induction Motor: Torque, Losses, Material

Permanent Magnet Motors for REDA ESP pumps: Reduce electricity consumption and parasitic load while increasing the range of operations. SLB. Permanent Magnet Motors for REDA ESP Pumps

Unlocking the Potential of PMMs: Lessons Learned in the Permian. Webcast. World Oil. June 18, 2025. (Baker Hughes).

Permanent Magnet Motors for REDA ESP pumps. SLB. Permanent Magnet Motors for REDA ESP Pumps

Magnefficient permanent magnet motor. Baker Hughes. Magnefficient permanent magnet motor | Baker Hughes