Centrifugal pump with thrust balance holes in diffuser

摘要

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.

主权项

1. 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.