US 11,913,464 B2
Lubricating an electric submersible pump
Christopher Wrighton, Inverurie (GB); and Sakethraman Mahalingam, Aberdeen (GB)
Assigned to Saudi Arabian Oil Company, Dhahran (SA)
Filed by Saudi Arabian Oil Company, Dhahran (SA)
Filed on Apr. 15, 2021, as Appl. No. 17/231,955.
Prior Publication US 2022/0333608 A1, Oct. 20, 2022
Int. Cl. F04D 29/06 (2006.01); F04D 1/06 (2006.01); F04D 13/08 (2006.01); E21B 43/12 (2006.01)
CPC F04D 29/061 (2013.01) [E21B 43/128 (2013.01); F04D 1/06 (2013.01); F04D 13/086 (2013.01)] 15 Claims
OG exemplary drawing
 
1. An assembly comprising:
an electric submersible pump configured to be disposed in a wellbore, the electric submersible pump comprising:
a pump configured to pressurize a wellbore fluid;
an electric motor coupled to the pump and configured to rotate the pump, the electric motor lubricated by a dielectric oil; and
a seal coupled to and disposed between the pump and the electric motor, the seal configured to prevent a wellbore fluid from the wellbore to enter into the electric motor and mix with the dielectric oil in the electric motor;
a sensor sub-assembly comprising one or more sensors, the sensor sub-assembly coupled to the electric motor and the seal between the electric motor and the seal, the one or more sensors configured to sense a condition of the dielectric oil in the electric motor and transmit a signal including a value representing the condition; and
a controller coupled to the electric motor and the one or more sensors, the controller configured to:
receive the signal including the value from the one or more sensors;
compare the value of the condition of the dielectric oil to a threshold value;
determine when the value of the condition of the dielectric oil is greater than the threshold value; and
responsive to determining that the value included in the signal is greater than a threshold value indicating a presence of contaminated dielectric oil, flow a clean dielectric oil from an accumulator to the electric motor to expel the contaminated dielectric oil out of the electric motor by the sensor sub-assembly and the seal into the wellbore.