Permanent Magnet Motors Help Reduce Carbon Footprint in Artificial Lift Systems
Authors: Carpenter Chris 
Published: April 2023

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This article, written by JPT Technology Editor Chris Carpenter, contains highlights of paper SPE 209736, “Carbon-Footprint Reduction Using Permanent Magnet Motors in Artificial Lift Systems,” by Luis F. Ararat, Ronald F. Herrera, and Sergio A. Parra, SierraCol Energy, et al. The paper has not been peer reviewed.

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Permanent-magnet-motor (PMM) technology was evaluated and implemented in the different artificial lift systems in the Llanos Norte (LLN) and La Cira Infantas (LCI) fields in Colombia, aiming to find a more-efficient motor to generate energy consumption savings and reduce carbon footprint. The complete paper shares technical details of the evaluation of tests performed in the field to validate the implementation of PMM technology in the artificial lift systems, the calculation of reduction of tons of carbon dioxide (CO2), and the main challenges in its application as an energy-efficient solution for future projects.

Field Background
The Llanos Orientales basin has 482 installed electrical-submersible-pump (ESP) and 24 sucker-rod-pump (SRP) wells at the time of writing, at an average depth of 7,450 ft true vertical depth (TVD). LCI, the other field under study, is Colombia’s first producing field and has three different artificial lift systems to produce its wells: 215 progressive-cavity-pump (PCP) installations, 691 SRP installations, and 257 ESP installations. The average depth of the field is 3,500 ft TVD.

Background for PMM Technology in the Operator’s Energy Fields
In 2016, the first attempt to implement PMM technology for ESP equipment in the LLN and LCI fields was made. The project began in November of the same year with a trial test in LLN with the installation of PMMs in two ESP wells. During the next 2 years, the testing conditions were adjusted, resulting in an energy-savings average of 15%, which validated its large-scale implementation, with more than 250 installations in LCI and LLN. Given the results obtained with ESP installations, the implementation of PMMs was considered for the PCP systems on the surface. The trial test began in 2019 by installing PMMs in two PCP wells in LCI, resulting in a 35% energy savings. The promising results spurred large-scale implementation in PCP initial completions since 2021. At the time of the paper’s writing, 12 wells have been installed. The field trial for SRP systems ran from 2020 to 2021, seeing the installation of five wells in LCI with an average energy savings of 18%.

Applications of PMM Technology in Artificial Lift Systems
ESP PMM. The ESP PMM features permanent magnets mounted in the rotor. The rotor flux is supplied by the magnets and therefore does not require an electrical power supply to generate this magnetic field. Permanent magnets installed in the motor rotor provide key advantages:
- By only using energy to generate the magnetic field in the stator, less energy is required for PPM operation.
- Slippage in magnetic flux between rotor and stator is zero.
- High efficiency (90–93%) over a wider operating range is achieved.
- Higher power density is seen than in conventional rotors.
- Electrical losses are reduced, a lower operating current is used, and less heat generation is experienced.