Abstract: An electrical submersible pump assembly has a pressure equalizer coupled to a lower end of a motor. The equalizer has a motor lubricant passage through which lubricant in the motor communicates with motor lubricant in the equalizing element. A valve element in the motor lubricant passage has a closed upper position and an open lower position. The valve element has a drive member on an upper end that mates with a shaft drive member on a lower end of the motor shaft while the valve element is in the upper position and disengages from the shaft drive member while the valve element is in the lower position. A locking feature between the valve element and the motor lubricant passage retains the valve element in the upper position and is releasable in response to rotation of the motor shaft in a selected direction.

Abstract: A well pump assembly has a submersible well fluid pump, motor, and seal section with a seal section shaft for transferring rotation of a motor drive shaft to a pump drive shaft. The seal section has a shaft passage through which the seal section shaft extends. A movable compensating element has an interior containing motor lubricant that is in fluid communication with motor lubricant in the motor and also in fluid communication with motor lubricant in the shaft passage. A shaft seal restricts well fluid from entry into the shaft passage. A lubricant pump driven by the shaft has a discharge within the shaft passage below the shaft seal. A recirculation passage extends from the shaft passage at a point between the discharge of the lubricant pump and the shaft seal to the interior of the compensating element.

Abstract: Upper and lower pressure equalizers couple to a lower end of a motor of an electrical submersible pump assembly. An intermediate connection having a liquid flow passage connects the pressure equalizers. A connection valve located in the liquid flow passage closes the liquid flow passage prior to connecting the pressure equalizers with each other, and opens the liquid flow passage after the connection between the pressure equalizers is made. A sensor lower equalizer wire extends from a sensor unit through the lower pressure equalizer to a lower electrical terminal at the upper end of the lower pressure equalizer. A sensor upper equalizer wire connects to the lower electrical terminal and extends through the upper pressure equalizer to an upper electrical terminal at the upper end of the upper pressure equalizer. A sensor motor wire extends downward from the motor into engagement with the upper electrical terminal.

Abstract: A bellows position monitoring arrangement to determine the axial position of a bellows assembly within the outer housing of a seal section or equalizer. The position can be correlated to an amount of motor oil being retained within the bellows assembly.

Abstract: An electrical submersible pump assembly has a thrust bearing mechanism with first and second thrust runners axially and rotationally secured to the shaft and located within a housing. First and second thrust receiving structures are rigidly mounted in the housing to receive thrust from the first and second thrust transferring devices. A deflectable member located in the first thrust transfer thrust device decreases in axial thickness in response to thrust of a selected level. The second thrust transfer thrust device has an axial length less than an axial distance from the second thrust receiving structure to the second thrust runner, defining an initial axial gap. During operation of the pump, the shaft and the first and second thrust runners move axially a limited extent, closing the gap and transferring thrust from the second thrust transfer device to the second thrust receiving structure.

Abstract: Seal sections for electric submersible pumps. Seal sections are described which include a combination of a barrier fluid to protect a seal from unfavorable ingress and control of differential pressure across the face of the seal.

Abstract: A well pump assembly has a submersible well fluid pump, motor, and seal section with a seal section shaft for transferring rotation of a motor drive shaft to a pump drive shaft. The seal section has a shaft passage through which the seal section shaft extends. A movable compensating element has an interior containing motor lubricant that is in fluid communication with motor lubricant in the motor and also in fluid communication with motor lubricant in the shaft passage. A shaft seal restricts well fluid from entry into the shaft passage. A lubricant pump driven by the shaft has a discharge within the shaft passage below the shaft seal. A recirculation passage extends from the shaft passage at a point between the discharge of the lubricant pump and the shaft seal to the interior of the compensating element.

Abstract: An electrical submersible pump assembly has a centrifugal pump with stages, each having an impeller and a diffuser. A shaft extending from an electrical motor rotates the impellers. In the stages, a thrust runner is coupled to the shaft for rotation in unison. A bushing is non rotatably mounted in a receptacle in the diffuser. The bushing has a bore that receives the body of the runner in sliding, rotating engagement. The bushing has a thrust receiving end engaged by the thrust face of the runner in rotating, sliding engagement to transfer thrust from the runner to the diffuser. An elastomeric compliant member between a cylindrical exterior of the bushing and the receptacle allows limited radial movement of the bushing relative to the diffuser.

Abstract: Upper and lower pressure equalizers couple to a lower end of a motor of an electrical, submersible pump assembly. An intermediate connection having a liquid flow passage connects the pressure equalizers. A connection valve located in the liquid flow passage closes the liquid flow passage prior to connecting the pressure equalizers with each other, and opens the liquid flow passage after the connection between the pressure equalizers is made. A sensor lower equalizer wire extends from a sensor unit through the lower pressure equalizer to a lower electrical terminal at the upper end of the lower pressure equalizer. A sensor upper equalizer wire connects to the lower electrical terminal and extends through, the upper pressure equalizer to an upper electrical terminal at the upper end of the upper pressure equalizer. A sensor motor wire extends downward from the motor into engagement with the upper electrical terminal.

Abstract: An electrical submersible pump assembly has a thrust bearing mechanism with first and second thrust runners axially and rotationally secured to the shaft and located within a housing. First and second thrust receiving structures are rigidly mounted in the housing to receive thrust from the first and second thrust transferring devices. A deflectable member located in the first thrust transfer thrust device decreases in axial thickness in response to thrust of a selected level. The second thrust transfer thrust device has an axial length less than an axial distance from the second thrust receiving structure to the second thrust runner, defining an initial axial gap. During operation of the pump, the shaft and the first and second thrust runners move axially a limited extent, closing the gap and transferring thrust from the second thrust transfer device to the second thrust receiving structure.

Abstract: An electrical submersible pump assembly has a pressure equalizer coupled to a lower end of a motor. The equalizer has a motor lubricant passage through which lubricant in the motor communicates with motor lubricant in the equalizing element. A valve element in the motor lubricant passage has a closed upper position and an open lower position. The valve element has a drive member on an upper end that mates with a shaft drive member on a lower end of the motor shaft while the valve element is in the upper position and disengages from the shaft drive member while the valve element is in the lower position. A locking feature between the valve element and the motor lubricant passage retains the valve element in the upper position and is releasable in response to rotation of the motor shaft in a selected direction.

Abstract: A bellows position monitoring arrangement to determine the axial position of a bellows assembly within the outer housing of a seal section or equalizer. The position can be correlated to an amount of motor oil being retained within the bellows assembly.

Abstract: Seal sections for electric submersible pumps. Seal sections are described which include a combination of a barrier fluid to protect a seal from unfavorable ingress and control of differential pressure across the face of the seal.

Abstract: An electrical submersible pump assembly has a centrifugal pump with stages, each having an impeller and a diffuser. A shaft extending from an electrical motor rotates the impellers. In the stages, a thrust runner is coupled to the shaft for rotation in unison. A bushing is non rotatably mounted in a receptacle in the diffuser. The bushing has a bore that receives the body of the runner in sliding, rotating engagement. The bushing has a thrust receiving end engaged by the thrust face of the runner in rotating, sliding engagement to transfer thrust from the runner to the diffuser. An elastomeric compliant member between a cylindrical exterior of the bushing and the receptacle allows limited radial movement of the bushing relative to the diffuser.

Abstract: A well pump assembly has a rotary pump with an electrical motor that contains a motor lubricant. A thrust chamber is mounted between the motor and the pump, the thrust chamber containing a thrust chamber lubricant. Seals prevent the entry of thrust chamber lubricant into the motor chamber. A pressure equalizing chamber is mounted to the motor for admitting well fluid. A first pressure barrier in the equalizing chamber equalizes the pressure of the thrust chamber lubricant with that of the well fluid. A second pressure barrier contained within the first pressure barrier equalizes the pressure of the motor lubricant with thrust chamber lubricant.

Abstract: A well pump assembly has a rotary pump with an electrical motor that contains a motor lubricant. A thrust chamber is mounted between the motor and the pump, the thrust chamber containing a thrust chamber lubricant. Seals prevent the entry of thrust chamber lubricant into the motor chamber. A pressure equalizing chamber is mounted to the motor for admitting well fluid. A first pressure barrier in the equalizing chamber equalizes the pressure of the thrust chamber lubricant with that of the well fluid. A second pressure barrier contained within the first pressure barrier equalizes the pressure of the motor lubricant with thrust chamber lubricant.