System, method and apparatus for electrical submersible pump with integrated gas separator

Abstract

A combined gas separator and pump in an electrical submersible pump assembly is disclosed. An integral discharge connector threadingly couples the gas separator and pump. The connector contains discharge ports for the discharge of the separated gas. The pump shaft and gas separator shaft are also coupled. Alternatively, a single pump shaft extends from the pump into the gas separator. In another alternative, the gas separator is completely integrated into the pump housing. The pump is modified by removing the intake of the pump and a sufficient number of pump stages to accommodate the gas separator components. A diverter tube is located in the pump housing and the pump housing is modified to include gas exit ports. All of the gas separator components are located in the modified pump housing, and the original pump intake is reattached at its original location.

1 . An electrical submersible pump (ESP) assembly, comprising:
 a pump having a pump housing;   a centrifugal gas separator having a gas separator housing with an intake and a diverter; and   a discharge connector extending between and threadingly coupled to the pump housing and the gas separator housing, the discharge connector having a plurality of discharge ports coupled to the diverter for discharging gas separated by the centrifugal gas separator.   
   
   
       2 . An ESP assembly according to  claim 1 , wherein the pump has a pump shaft, the centrifugal gas separator has a gas separator shaft, and the pump shaft is secured to the gas separator shaft with a coupling. 
   
   
       3 . An ESP assembly according to  claim 2 , wherein the discharge connector contains a bearing for stabilization of the pump shaft, the coupling and the gas separator shaft. 
   
   
       4 . An ESP assembly according to  claim 2 , wherein a downstream end of the gas separator shaft is located in the discharge connector, the diverter has an inner diameter gas passage in communication with the discharge ports in the discharge connector, an outer diameter liquid passage is located between an outer portion of the diverter and an inner portion of the discharge connector. 
   
   
       5 . An ESP assembly according to  claim 2 , wherein the coupling is located within the discharge connector downstream from the diverter. 
   
   
       6 . An ESP assembly according to  claim 1 , wherein the diverter is located completely within an axial length of the discharge connector. 
   
   
       7 . An ESP assembly according to  claim 1 , wherein the pump housing has an axis and an upstream end, the pump has a pump shaft that extends in an axial direction beyond the upstream end, through the discharge connector, and into the centrifugal gas separator, such that the pump shaft operates the pump and the centrifugal gas separator. 
   
   
       8 . An electrical submersible pump (ESP) assembly, comprising:
 a pump having a pump housing with an axis, an upstream end, a pump shaft that extends in an axial direction, a plurality of pump stages, and a plurality of discharge ports formed through a wall of the pump housing;   a centrifugal gas separator located completely inside an axial length of the pump housing and having an auger and a rotor coupled to the pump shaft for rotation therewith, and a diverter located between the rotor and the pump stages, the diverter being coupled to the discharge ports for discharging gas separated by the centrifugal gas separator through the wall of the pump housing; and   a pump intake located adjacent the upstream end of the pump housing upstream from the auger and the rotor.   
   
   
       9 . An ESP assembly according to  claim 8 , wherein the diverter is mounted to the pump housing to prevent rotation of the diverter relative to the pump housing, and the pump shaft extends out of the pump housing beyond the upstream end of the pump housing. 
   
   
       10 . An ESP assembly according to  claim 8 , wherein the diverter has an inner diameter gas passage in communication with the discharge ports, an outer diameter liquid passage is located between an outer portion of the diverter and an inner portion of the pump housing. 
   
   
       11 . A method of integrating a centrifugal gas separator and a pump, comprising:
 (a) providing an electrical submersible pump (ESP) assembly having a pump with a pump housing, a pump shaft, a plurality of pump stages, and a pump intake;   (b) removing the pump intake from the pump housing;   (c) removing at least one of the pump stages from the pump housing to accommodate components of a centrifugal gas separator;   (d) installing the centrifugal gas separator in the pump housing;   (e) forming gas discharge ports in a wall of the pump housing in communication with a gas discharge from the centrifugal gas separator; and   (f) reinstalling the pump intake on the pump housing such that the centrifugal gas separator is located completely inside an axial length of the pump housing.   
   
   
       12 . A method according to  claim 11 , wherein in step (b) the pump intake defines an original location for the pump intake on the pump housing, and step (g) comprises securing the pump intake in the original location. 
   
   
       13 . A method according to  claim 11 , wherein step (d) comprises attaching a diverter, a rotor and an auger on the pump shaft, and step (e) comprises coupling the gas discharge ports in the wall of the pump housing with an inner diameter gas passage in the diverter. 
   
   
       14 . A method according to  claim 13 , wherein the diverter is mounted to the pump housing to prevent rotation of the diverter relative to the pump housing, and the pump shaft extends out of the pump housing beyond the upstream end of the pump housing. 
   
   
       15 . A method according to  claim 13 , wherein the diverter has an inner diameter gas passage in communication with the discharge ports, an outer diameter liquid passage is located between an outer portion of the diverter and an inner portion of the pump housing.