Motorized pump

Abstract

A motorized pump to pump fluid. The motorized pump includes a shaft disposed in a center portion of the motorized pump, a motor having a motor stator, and a pump having an internal diffuser and an external impeller, wherein the motor stator radially surrounds the pump. A housing radially encloses the motor stator, the internal diffuser, and the external impeller. The motor stator is disposed adjacent the housing.

1 . A motorized pump to pump fluid, comprising:
 a shaft disposed in a center portion of the motorized pump, wherein the shaft does not rotate in operation;   a motor comprising a motor stator comprising laminations and windings;   a pump comprising an internal diffuser and an external impeller, wherein the motor stator radially surrounds the pump, and wherein an axial length of the shaft is greater than an axial length of the external impeller; and   a housing radially enclosing the motor stator, the internal diffuser, and the external impeller, wherein the motor stator is disposed adjacent the housing.   
     
     
         2 . The motorized pump of  claim 1 , wherein the pump comprises a multi-stage centrifugal pump, wherein the shaft extends through a stage of the multi-stage centrifugal pump, and wherein the motorized pump is an electrical submersible pump (ESP) motor and ESP pump and does not comprise an ESP motor protector. 
     
     
         3 . The motorized pump of  claim 1 , wherein the external impeller comprises permanent magnets to engage the motor stator via electromagnetic coupling to rotate the external impeller about the shaft, the external impeller comprising a flow path for fluid pumped by the motorized pump. 
     
     
         4 . The motorized pump of  claim 3 , wherein the permanent magnets of the external impeller comprise a motor rotor of the motor. 
     
     
         5 . The motorized pump of  claim 1 , wherein the motor comprises an annular motor rotor mechanically coupled to the external impeller, wherein an axial length of the annular motor rotor is longer than an axial length of the external impeller, the annular motor rotor comprising permanent magnets to engage the motor stator to rotate the annular motor rotor and the external impeller about the shaft. 
     
     
         6 . The motorized pump of  claim 5 , wherein the permanent magnets to engage magnetic fields of the motor stator generated by electrical power delivered to the motor via a power cable, and wherein the motor radially encloses the pump. 
     
     
         7 . The motorized pump of  claim 1 , wherein the internal diffuser is disposed adjacent the shaft and comprises a hydraulic protrusion. 
     
     
         8 . The motorized pump of  claim 7 , wherein the hydraulic protrusion comprises a blade. 
     
     
         9 . A motorized pump comprising:
 a shaft disposed at a center portion of the motorized pump, wherein the shaft does not rotate in operation;   a motor comprising a motor stator comprising laminations and windings;   a pump comprising a multi-stage centrifugal pump comprising multiple hydraulic stages, each stage comprising an internal diffuser and an external impeller, the external impeller for fluid pumped by the motorized pump, wherein an axial length of the shaft is greater than an axial length of the external impeller; and   a housing radially enclosing the motor stator, the internal diffusers, and the external impellers, wherein the motor stator radially encloses the pump.   
     
     
         10 . The motorized pump of  claim 9 , wherein the internal diffuser comprises a blade. 
     
     
         11 . The motorized pump of  claim 9 , wherein the external impeller comprises permanent magnets to engage the motor stator via electromagnetic coupling to rotate the external impeller about the shaft. 
     
     
         12 . The motorized pump of  claim 9 , wherein the motor comprises an annular motor rotor mechanically coupled to the external impeller, the annular motor rotor comprising permanent magnets to engage the motor stator via electromagnetic coupling to rotate the annular motor rotor and the external impeller about the shaft. 
     
     
         13 . The motorized pump of  claim 12 , wherein the motor radially surrounds the pump. 
     
     
         14 . The motorized pump of  claim 9 , wherein the motor comprises an annular motor rotor comprising permanent magnets to engage the motor stator via electromagnetic coupling to rotate the annular motor rotor around the shaft, wherein the external impeller is mechanically coupled to the annular motor rotor to rotate with the annular motor rotor around the shaft, and wherein the annular motor rotor comprises steel laminations. 
     
     
         15 . The motorized pump of  claim 9 , wherein the motorized pump is an electrical submersible pump (ESP) motorized pump and does not comprise an ESP motor protector. 
     
     
         16 . A method of operating an electrical submersible pump (ESP) comprising a motorized pump, the method comprising:
 pumping, by the motorized pump of the ESP, production fluid from a wellbore, wherein the motorized pump comprises a pump and a motor stator radially enclosing the pump, the pump comprising an external impeller and an internal diffuser, wherein the pumping comprises:
 receiving the production fluid at an inlet of the pump; 
 receiving the production fluid at the external impeller and rotating the external impeller around a shaft of the motorized pump, wherein the shaft does not rotate in operation, and wherein an axial length of the shaft is greater than an axial length of the external impeller; 
 flowing the production fluid through a flow path of the internal diffuser. 
   
     
     
         17 . The method of  claim 16 , comprising lowering the motorized pump into the wellbore, wherein the motor stator comprises windings, wherein the ESP does not comprise a motor protector, wherein receiving the production fluid at the inlet comprises receiving the production fluid from perforations in a casing of the wellbore, and wherein the production fluid comprises hydrocarbon. 
     
     
         18 . The method of  claim 16 , wherein the pump comprises a multi-stage centrifugal pump, wherein the pumping comprises discharging the production fluid through a production conduit to an Earth surface, wherein the production fluid comprises oil and gas, and wherein the motorized pump does not comprise a motor protector section. 
     
     
         19 . The method of  claim 16 , wherein rotating the external impeller comprises engaging permanent magnets of the external impeller with the motor stator via electromagnetic coupling to rotate the external impeller around the shaft. 
     
     
         20 . The method of  claim 16 , wherein the motor comprises an annular rotor motor mechanically coupled to the external impeller, wherein rotating the external impeller comprises engaging permanent magnets of the annular motor rotor via electromagnetic coupling to rotate the annular motor rotor and the external impeller around the shaft, and wherein the motor radially surrounds the pump. 
     
     
         21 . The method of  claim 16 , comprising:
 receiving electricity via a power cable to the motor;   generating, via the electricity, magnetic fields of the motor stator, wherein the internal diffuser is disposed adjacent the shaft and comprises a vane or blade.