Turbine powered electrical submersible pump system

A method for artificially lifting fluid from a wellbore, the method comprising:

• activating a battery of an artificial lift unit disposed downhole at a predetermined pump setting depth inside a tubular space of a production tubing of a wellbore;
• supplying power from the activated battery to a prime mover of the artificial lift unit to power the prime mover with battery power;
• driving a pump of the artificial lift unit with the prime mover to pressurize wellbore fluid flowing in from an intake port of the pump, and discharge the pressurized wellbore fluid from a discharge port of the pump;
• generating electric power from the pressurized wellbore fluid by flowing the pressurized wellbore fluid discharged from the discharge port of the pump through a flow passage of a turbine generator of the artificial lift unit;
• and
• supplying the electric power generated by the turbine generator to the prime mover to power the prime mover with the turbine generator electric power.

A turbine-powered electrical submersible pump unit, comprising:

• an electrical submersible pump (ESP) that has a pump intake port and a pump discharge port, wherein the ESP is adapted to intake wellbore fluid from the pump intake port at a pump intake pressure, pressurize the wellbore fluid, and discharge the wellbore fluid from the pump discharge port at a pump discharge pressure that is higher than the pump intake pressure;
• a motor that is coupled to the ESP and that drives the ESP;
• a turbine generator that has a flow passage for the pressurized wellbore fluid, the flow passage being disposed between a turbine intake port and a turbine discharge port of the turbine generator, wherein the turbine intake port is fluidly coupled to the pump discharge port, wherein the turbine generator is configured to generate electric power from the pressurized wellbore fluid flowing through the flow passage of the turbine generator, and wherein the turbine generator is electrically coupled to the motor and is configured to power the motor with the electric power generated from the flowing pressurized wellbore fluid;
• and
• a battery that is electrically coupled to the motor and is configured to initially power the motor, wherein the turbine generator is further electrically coupled to the battery and is configured to recharge the battery.