Patent ID: 6361272
Filing Date: 2002-03-26
Classification: E21B,F04D

Abstract:
A centrifugal submersible pump comprising:a) a generally cylindrical pump casing of such diameter as to fit within a well borehole for insertion and removal of the pump; b) a pump intake in the vicinity of a base of said pump; c) an axial drive shaft extending substantially the length of said pump and adapted to be driven by a submersible motor located below said pump; d) a plurality of centrifugal impellers spaced along said axial drive shaft, each of said centrifugal impellers having a central hub attached for rotation to said axial drive shaft and having an opening adjacent said drive shaft for fluid intake; e) a plurality of diffusers corresponding, each corresponding to one of said centrifugal impellers to form a series of pump stages; f) said diffusers being supported by inward compression of said pump housing so as to remain stationary relative to said centrifugal impellers, and having a central bore of such diameter as to allow fluid to travel upward through the annulus between said central bore and said axial drive shaft and into said impeller intake; g) a pump outlet located and attached for flow to a conduit for receiving pumped fluid in the vicinity of an upper end of said pump housing for connection to a conduit for carrying said fluid to the surface, or into the casing of another immersible pump; h) a cylindrical coaxial shroud located along the lower portion of said pump housing and having a plurality of fluid inlet holes located near the upper end of said shroud, said shroud being sealed at its upper end with said pump housing and at its lower end with said pump housing at a location below said pump inlet such that all intake fluid must enter said pump through said shroud.