Patent attributes
An assembly and a method for lubricating an electric submersible pump assembly disposed in a wellbore are described. The assembly includes a pump to pressurize a wellbore fluid and an electric motor to rotate the pump. The electric motor is lubricated by a dielectric oil. A sensor is coupled to the electric motor to sense a condition of the electric motor and transmit a signal including a value representing the condition. A controller is coupled to the electric motor and the sensor. The controller receives the signal from the sensor, compares the value to a threshold value, determines when the value is greater than the threshold value, and responsive to determining that the value is greater than a threshold value indicating a presence of contaminated dielectric oil, flows a clean dielectric oil from an accumulator to the electric motor to expel the contaminated dielectric oil out of the electric motor.
