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: 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.