Gas-lock re-prime device for submersible pumps

A submersible pump assembly for pumping well fluids to a surface location, the pump assembly comprising:

• a string of production conduit;
• a centrifugal pump having an inlet and an outlet;
• a valve housing connected between the pump outlet and the production conduit, the valve housing having a valve inlet, a valve outlet, and a priming outlet;
• a valve member carried in the valve housing and axially movable in response to pump pressure from a pumping position to a priming position, the valve member being biased toward the priming position;
• a priming conduit connecting the priming outlet of the valve housing to the inlet of the pump;
• and wherein
• when the pump stage is pumping well fluid, the valve member is moved by pump pressure to the pumping position, in which well fluids flow from the inlet of the valve housing to the production conduit and well fluids are prevented from flowing into the priming conduit;
• and
• when the pump stage ceases to pump well fluid at a desired rate, the valve member returns to the priming position, in which well fluids flow from the production conduit into the priming conduit and into the pump inlet for priming the pump.

A submersible pump assembly for pumping well fluids, the pump assembly comprising:

• a pump having an inlet and an outlet;
• a valve housing connected to the pump outlet, the valve housing having upper and lower chambers separated by a partition having an orifice, a valve inlet in the lower chamber connected to the pump, a valve outlet in the upper chamber adapted to be connected to a production conduit, and a priming outlet located in the upper chamber;
• a priming conduit extending from the priming outlet to the inlet of the pump;
• a spool valve member having a central portion that sealingly engages the orifice;
• a spring that urges the valve member to a lower position, with the central portion blocking fluid flow through the orifice and allowing flow from the upper chamber into the priming conduit;
• and wherein
• pump pressure overcomes the force exerted by the spring and pushes the valve member to an upper position, the central portion blocking the priming outlet and allowing fluid flow through the orifice from the lower chamber into the upper chamber.

A method of priming a pump of a submersible pump assembly, the method comprising:

• (a) suspending a submersible pump assembly on a production conduit;
• (b) pumping well fluids with the pump up the conduit;
• (c) sensing the pump pressure;
• and
• (d) if the pump pressure ceases, diverting well fluid in the production conduit around the pump to a pump inlet to prime the pump.

A method of priming a pump of a submersible pump assembly, the method comprising:

• (a) connecting a valve housing to an outlet of a submersible pump, the valve housing having a valve outlet connected to a production conduit and a priming outlet connected by a priming conduit to an inlet of the pump;
• (b) pumping well fluids with the pump from the inlet of the pump to the valve housing, the fluid pressure moving a valve member in the valve housing to a pumping position to open a production path between the pump and the production conduit;
• and
• (c) if the pump ceases to pump fluids, moving the valve member to a priming position to close the production path and open a priming path, the priming path connecting the production conduit to the inlet of the pump via the priming conduit for priming the pump.