Centrifugal pump with thrust balance holes in diffuser
AssigneeBaker Hughes Incorporated
InventorsKetankumar K. Sheth, Brown Lyle Wilson
Life of this patent
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Abstract
A centrifugal pump has alternating impellers and diffusers. One or more vent holes extend through one or more vanes of one or more diffusers. In an upthrust condition, high pressure production fluid from an upper impeller is able to pass through the one or more vent holes, and thereby exert force on the preceding impeller. The force exerted on the preceding impeller offsets the upthrust force acting against the preceding impeller.
Claims20
An electrical submersible pump assembly, comprising:
- a centrifugal pump having a longitudinal axis;
- a motor operatively coupled to the pump for driving the pump;
- the pump having a plurality of stages, each of the stages comprising an impeller and a diffuser:
- the impeller having a central intake centered on the axis;
- the diffuser having a lower surface, an upper surface, and a plurality of diffuser passages between the lower and upper surfaces and extending toward the axis from a diffuser inlet to a diffuser outlet centered on the axis and registered with the intake of the impeller;
- and
- a vent passage extending through the diffuser from the lower surface to the upper surface, the vent passage being spaced radially outward from the diffuser outlet and below the impeller.
A method for pumping fluid from a wellbore comprising:
- providing a submersible pump in the wellbore comprising:
- a pump housing having a longitudinal axis;
- a plurality of stages within the pump housing;
- each of the stages comprising:
- a diffuser and an impeller, the diffuser having a concentric outlet registering with an inlet of the impeller;
- and
- a vent passage extending axially through the diffuser from an upper surface to a lower surface of the diffuser, the vent passage being spaced radially outward from the outlet of the diffuser;
- the method comprising:
- rotating the impeller of each of the stages to force wellbore fluid through diffuser passages of the diffuser of each of the stages;
- and
- communicating wellbore fluid pressure through the vent passage from the upper surface to a void at the lower surface of the diffuser.
An electrical submersible pump system for pumping fluid from a wellbore, the system comprising:
- a pump comprising:
- a pump housing having a longitudinal axis;
- first and second impellers coaxially stacked within the pump housing;
- a diffuser coaxially between the impellers, the diffuser having an outlet encircled by a diffuser downthrust surface, the first impeller having an inlet encircled by an impeller downthrust surface that rotatably engages the diffuser downthrust surface;
- a vent passage extending through the diffuser from a lower surface to an upper surface of the diffuser radially outward from the impeller and diffuser downthrust surfaces;
- wherein the system further comprises:
- a seal section connected to the pump;
- a motor connected to the seal section;
- and
- a shaft operably connected to the motor and the pump, the shaft passing through the seal section and operable to transfer torque from the motor to the impellers.
Dependencies are inferred from the claim text.