Migrating from hydraulic to electric motor solutions on wireline tools offers numerous benefits, including a significant reduction in maintenance as well as a significant increase in control / “programmability” of tooling functions. However, the inherently low efficiency of traditional induction motors severely limits the number of motors that can be deployed per tool due to overall limitations on available tool string power, and motor life can be unacceptably short due to the high ambient temperature. These challenges, and others, have been overcome in permanent magnet BLDC electric motors from Windings.
A design study conducted by Windings’ engineers revealed that induction motor topology is not capable of meeting the needs of wireline service companies for higher power density and high efficiency over the entire operating envelope. Because permanent magnet-based rotors do not require induction of a magnetic field, motors based on this topology have efficiencies greater than 90% over a wide speed / torque range and offer up to twice the power density of a comparable induction-based motor design.
Windings electric motor solution for wireline hydraulic pump applications provides 5kW of power at 8,000RPM while operating continuously at 200°C ambient temperature. Efficiency is over 90% higher than traditional induction motors, almost doubling the productive working time. And at 3-1/8” in diameter and 11” long, the overall tool string package length can be reduced by up to 2/3. Relative to a typical induction motor solution, the Windings permanent magnet motor provides:
50% reduction in motor package size
Over 90% increase in efficiency, almost doubling the productive time between battery swaps