Determining electrical submersible pump lifetime expectancy

An electrical submersible pump motor head comprising:

• a motor head case;
• a pothead coupled to the motor head case;
• one or more toroidal transformers positioned within the motor head case;
• a power cable positioned within the motor head case, the power cable coupled to the pothead and extending through the one or more toroidal transformers;
• and
• a sensor module configured to perform operations comprising:
• receiving power from the one or more toroidal transformers;
• detecting a condition of the motor;
• and
• transmitting a signal representing the condition of the motor;
• and
• a local controller contained within the motor head, the local controller coupled to the motor and the sensor module, the local controller configured to perform operations comprising:
• receiving electrical power from the one or more toroidal transformers;
• receiving the signal representing the condition of the motor;
• based on the condition of the motor, determining a mass flow rate of the motor;
• and
• based on the mass flow rate of the motor, determining a life expectancy of the motor.

The electrical submersible pump motor head of claim 18, wherein the condition of the motor is the differential temperature across the outer surface of the motor, determining the mass flow rate of the motor comprises calculating the mass flow rate by

• m
• ˙
• =
• Q
• ˙
• C
• p
• (
• T
• out
• -
• T
• in
• )
• ,
• wherein {dot over (m)} is the mass flow rate of fluids in kg/sec through the motor, {dot over (Q)} is the energy supplied to the motor in Watts, Cp is a specific heat capacity of the fluid in J/kgK in the motor, Tout is a fluid temperature at the motor uphole end in ° C., and Tin is a fluid temperature at the motor downhole end in ° C.

A method comprising:

• generating power by one or more toroidal transformers in a motor head of an electrical submersible pump;
• supplying the power to a sensor module and a local controller positioned in the motor head;
• determining a differential temperature across an outer surface of the motor;
• based on the differential temperature across the outer surface of the motor, determining a mass flow rate of a fluid flowing through the motor by
• m
• ˙
• =
• Q
• ˙
• C
• p
• (
• T
• out
• -
• T
• in
• )
• ,
• wherein {dot over (m)} is the mass flow rate of the fluid in kg/sec in the motor, {dot over (Q)} is the power supplied to the motor in Watts, Cp is a specific heat capacity of the fluid in J/kgK in the motor, Tout is a fluid temperature at a motor uphole end in ° C., and Tin is a fluid temperature at a motor downhole end in ° C.;
• and
• based on the mass flow rate of the motor, determining a life expectancy of the motor.