Induction Vs. permanent magnet motors for electric submersible pumps field and laboratory comparisons

Most hydrocarbon production using submersible pumps requires the pumping of fluid that is 95% water or higher. Energy used to produce salt water is wasted, and disposal is expensive. Electricity costs are significant and system efficiency is a major concern. In this application induction motors are less efficient than permanent magnet motors. Laboratory tests measured efficiency, power factor, kilowatts, current and speed at various loads and frequencies. Field-tests measured input power and flow, using the same pump for both systems with negligible well drawdown. On average the permanent magnet motor used 20% less power than the induction motor.