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: An electrical submersible pump assembly includes a production pump, a motor containing a motor lubricant, and a seal section coupled between the motor and the pump. A drive shaft extends through the seal section, the drive shaft being rotated by the motor for driving the production pump. A mechanical face seal in the seal section seals around the shaft. A circulation pump is mounted to the shaft above the face seal for rotation therewith. An inlet passage leads from an exterior of the seal section to the circulation pump to deliver well fluid to the circulation pump. An outlet passage leads from the circulation pump to the exterior of the seal section to discharge well fluid exterior of the seal section. The rotating component of the face seal is located in the outlet passage.

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 pump driven by a motor. A pressure compensator has first and second bellows units axially separated from each other. Each of the first and second bellows units are movable between an increased volume position and a decreased volume position and have a bias toward the decreased volume position. The bias of the first bellows unit is greater than the bias of the second bellows unit. The greater bias of the first bellows unit over the second bellows unit causes the second bellows unit to be at a full volume position at a lower level of the pressure differential than the level at which the first bellows unit is at the full volume position.

Abstract: An electrical submersible pump assembly has a seal section coupled to a motor that drives the pump. The seal section has first and second end members spaced axially apart from each other. An outer bellows has a fixed end mourned to the first end member and a floating end that moves axially relative to the fixed end. A rigid, tubular interconnect member has an inner end within the outer bellows and an cuter end fixed to the floating end of the outer bellows. An inner bellows has a floating end secured to the inner end of the interconnect member and a fixed end secured to the second end member. An interconnect evacuation passage extends axially through a side wall of the interconnect member. A first end member evacuation passage extends through the first end member and registers with the interconnect evacuation passage while the outer bellows is contracted.

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 number modules including a pump, a motor and a pressure equalizer. Each module has a rotatable shaft with a splined end that joins a splined end of another module, and those splined ends may differ in dimensions. A coupling that joins the shafts has a first shell has a splined bore that mates with the splined end of the first shaft. A second shell has a splined bore that mates with the splined end of the second shaft. An adopter has a first splined end in mating engagement with the splined bore of the first shell and a second splined end in mating engagement with the splined bore of the second shell. Fasteners secure the adapter to the shells. An annular seal isolates fluid communication between the first shell bore and the second shell bore.

Abstract: An electrical submersible pump assembly includes a production pump, a motor containing a motor lubricant, and a seal section coupled between the motor and the pump. A drive shaft extends through the seal section, the drive shaft being rotated by the motor for driving the production pump. A mechanical face seal in the seal section seals around the shaft. A circulation pump is mounted to the shaft above the face seal for rotation therewith. An inlet passage leads from an exterior of the seal section to the circulation pump to deliver well fluid to the circulation pump. An outlet passage leads from the circulation pump to the exterior of the seal section to discharge well fluid exterior of the seal section. The rotating component of the face seal is located in the outlet passage.

Abstract: An electrical submersible pump assembly has a number modules including a pump, a motor and a pressure equalizer. Each module has a rotatable shaft with a splined end that joins a splined end of another module, and those splined ends may differ in dimensions. A coupling that joins the shafts has a first shell has a splined bore that mates with the splined end of the first shaft. A second shell has a splined bore that mates with the splined end of the second shaft. An adopter has a first splined end in mating engagement with the splined bore of the first shell and a second splined end in mating engagement with the splined bore of the second shell. Fasteners secure the adapter to the shells. An annular seal isolates fluid communication between the first shell bore and the second shell bore.

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 pump driven by a motor. A pressure compensator has first and second bellows units axially separated from each other. Each of the first and second bellows units are movable between an increased volume position and a decreased volume position and have a bias toward the decreased volume position. The bias of the first bellows unit is greater than the bias of the second bellows unit. The greater bias of the first bellows unit over the second bellows unit causes the second bellows unit to be at a full volume position at a lower level of the pressure differential than the level at which the first bellows unit is at the full volume position.

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.