Artificial lift pump

Abstract

A pump comprising a plurality of impellers stacked on top of each other via a pump shaft, a diffuser corresponding to each impeller, a body housing the impellers, the diffusers, and the pump shaft, and a protector thrust bearing at one end of the pump shaft.

What is claimed is: 
     
         1 . A pump for pumping fluid, the pump comprising: 
 a plurality of impellers stacked on top of each other via a pump shaft;    a diffuser corresponding to each impeller;    a body housing the plurality of impellers, each diffuser corresponding to each impeller, and the pump shaft; and    a protector thrust bearing at a first end of the pump shaft.   
     
     
         2 . The pump of  claim 1 , further comprising a gap at a second end of the pump shaft, wherein the gap is configured to allow at least one of the plurality of impellers to float when one or more stage deflections exceed a shaft lift. 
     
     
         3 . The pump of  claim 1 , further comprising a spring at a second end of the pump shaft, wherein the spring is configured to secure the plurality of impellers. 
     
     
         4 . The pump of  claim 1 , wherein the plurality of impellers are stacked hub-to-hub. 
     
     
         5 . The pump of  claim 1 , wherein the plurality of impellers are configured to move along the shaft in an upward direction. 
     
     
         6 . The pump of  claim 1 , wherein a downthrust generated by the plurality of impellers is configured to be transferred to the protector thrust bearing through the shaft. 
     
     
         7 . The pump of  claim 1 , wherein the pump is configured to limit a transfer of a thrust load such that when a deflection exceeds a shaft lift, the thrust load from the stages where the deflection exceeds the shaft lift stage is transferred to an adjacent diffuser. 
     
     
         8 . The pump of  claim 1 , wherein the pump is part of an electric submersible pump (ESP) system. 
     
     
         9 . The pump of  claim 1 , wherein the bottom of the pump shaft or an impeller hub comprises a two-piece ring held in place with a spacer and a retaining ring. 
     
     
         10 . An electrical submersible pump (ESP), the ESP comprising: 
 a plurality of impellers;    a plurality of diffusers corresponding to each of the plurality of impellers;    a pump shaft connecting the plurality of impellers;    a protector thrust bearing at a bottom end of the pump shaft; and    a clearance or spring at a top end of the pump shaft configured to allow limited impeller movement during stage deflection in order to reduce thrust transfer.   
     
     
         11 . The ESP of  claim 10 , further comprising a gap at a second end of the pump shaft, wherein the gap is configured to allow at least one of the plurality of impellers to float when one or more stage deflections exceed a shaft lift. 
     
     
         12 . The ESP of  claim 10 , further comprising a spring at a second end of the pump shaft, wherein the spring is configured to secure the plurality of impellers. 
     
     
         13 . The ESP of  claim 10 , wherein the plurality of impellers is configured to float at a top end of the pump shaft via a gap. 
     
     
         14 . The ESP of  claim 10 , wherein a downthrust generated by one or more of the plurality of impellers is configured to be transferred to the protector thrust bearing through the shaft. 
     
     
         15 . The ESP of  claim 10 , wherein the ESP is configured to limit a transfer of a thrust load such that when a deflection exceeds a shaft lift, the thrust load from the stages where the deflection exceeds the shaft lift stage is transferred to an adjacent diffuser. 
     
     
         16 . The ESP of  claim 10 , further comprising a retaining ring, a spacer, and a two-piece ring to transfer thrust load from one or more of the plurality of impellers to the pump shaft. 
     
     
         17 . The ESP of  claim 16 , further comprising an unconstrained end on the one or more of the plurality of impellers. 
     
     
         18 . A method of reducing wear in a pump, the method comprising: 
 stacking a plurality of impellers on a pump shaft;    providing a diffuser corresponding to each impeller;    housing the plurality of impellers, each corresponding diffuser, and the pump shaft in a body;    providing a protector thrust bearing at one end of the pump shaft; and    providing a clearance or spring at the other end of the pump shaft to allow for impeller float during deflection.   
     
     
         19 . The method of  claim 18 , further comprising allowing one or more of the plurality of impellers to float, via a gap, when one or more stage deflections exceed a shaft lift. 
     
     
         20 . The method of  claim 18 , further comprising limiting a transfer of a thrust load such that when a deflection exceeds a shaft lift, the thrust load from only one stage is transferred to an adjacent diffuser.