Luke Hebert, Weatherford
Koda Resources
In response to rising demands for operational efficiency, power challenges, environmental responsibility, and workplace safety, this paper presents a case study on the integration of high-efficiency Permanent Magnet Motors (PMMs) and Power Regenerative Variable Speed Drive systems on long-stroke and conventional pumping units. This initiative was the result of a strategic collaboration between Weatherford and the operators, aimed at optimizing artificial lift operations while reducing energy consumption and enhancing safety performance.
The technical approach involved retrofitting existing rod lift systems with Weatherford’s Permanent Magnetic Motor’s and the Power Regenerative (PRSi) Variable Speed Drive system. Unlike conventional induction motor systems that dissipate regenerative energy as heat, the PRSi system captures and stores excess energy using ultra-capacitor technology and redistributes it during peak load demand. This dual-technology integration provides a more efficient energy management process and improves motor control during both acceleration and deceleration cycles of the pumping unit. While conventional regenerative drive technology pushes excess power back into the grid, the PRSi system is a closed loop approach that ensures its viability for greenfield applications running on genset power.
A field implementation for a Bakken operator demonstrated up to 49% reduction of power consumption, resulting in an estimated annual reduction of 106,230 kg of COâ‚‚ emissions and a field implementation for a Permian operator demonstrated 37% reduction of power consumption. Additionally, the system enhanced operational safety by decreasing the need for manual intervention, thereby keeping personnel out of high-risk zones. Operational performance data is presented to validate improvements in energy utilization, equipment longevity, and process control.
This paper offers novel insights into how existing rod lift assets can be transformed into highly efficient, regenerative systems through advanced motor technology and intelligent energy capture. The results support a broader industry shift toward sustainable production practices while delivering tangible value in operational cost savings and safety enhancements.