Gas-lock re-prime shaft passage in submersible well pump and method of re-priming the pump

An apparatus for pumping well fluid from a well, comprising:

• a centrifugal pump assembly having a shaft with a longitudinal axis, impellers mounted to the shaft for rotation therewith, a discharge adapter at an upper end of the pump assembly with a discharge adapter bore into which well fluid discharged by the impellers flows;
• a shaft passage in the shaft, the shaft passage having an open upper end above the impellers and a closed lower end below the impellers;
• at least one outlet port extending laterally from the shaft passage below the impellers;
• and
• a gas-lock re-priming device in the shaft passage for diverting a portion of well fluid in the discharge adapter bore through the shaft passage and out the outlet port.

A method for pumping well fluid from a well with a centrifugal pump assembly having a shaft, impellers mounted to the shaft for rotation therewith, and a discharge adapter at a first end of the pump assembly into which well fluid discharged by the impellers flows, the method comprising;

• providing the shaft with a shaft passage along a longitudinal axis of the pump assembly and at least one outlet port extending laterally from the shaft passage to an inlet of at least one of the impellers;
• installing in the shaft passage a gas-lock re-priming device;
• and
• diverting a portion of well fluid in the discharge adapter through the shaft passage and out the outlet port.