Abstract: A submersible pump assembly includes a seal section connected to a motor, the seal section having a housing with an outboard bearing at a housing pump end in radial supporting engagement with a drive shaft. An inboard bearing is also in the housing pump end, axially spaced from the outboard bearing, and in radial supporting engagement with the shaft. A barrier fluid chamber in the housing pump end contains a barrier fluid. A primary shaft seal is located within the barrier fluid chamber and seals the barrier fluid in the barrier fluid chamber from the motor lubricant. A secondary shaft seal is mounted in the barrier fluid chamber between the primary shaft seal and the outboard bearing. The secondary shaft seal seals the barrier fluid in the barrier fluid chamber from well fluid exterior of the housing pump end.

Abstract: A well pump assembly includes a centrifugal pump having a housing with a cylindrical internal side wall. Upper and lower diffusers are located in the housing. A metal-to-metal seal seals an upper end portion of the lower diffuser to the lower end portion of the upper diffuser. The seal also has an outer surface that frictionally engages the internal side wall of the housing. The seal is energized in response to an axial force exerted between the upper and lower diffusers. One version has a metal seal ring located in mating recesses on the outer walls of the diffusers. Another version includes an inner lip on one of the end portions of the diffusers that extends within and deflects an outer lip on the other of the end portions of the diffusers.

Abstract: A submersible well pump assembly has a pump, a motor, and a tubular pressure equalizer housing located between the pump and the motor. A rotatable drive shaft extends within the housing on the axis for driving the pump. A guide tube surrounds the drive shaft, defining an inner annulus between the drive shaft and the guide tube and an outer annulus between the housing and the guide tube. A well fluid inlet path admits well fluid into the outer annulus. A hub assembly is pivotally mounted to the guide tube. The hub assembly has a communication passage with having at least one lateral portion extending away the axis and a communication passage opening spaced from the axis and in fluid communication with the outer annulus. The hub assembly has a counterweight that rotates the communication passage opening to a point above the axis while the axis is horizontal.

Abstract: A well pump seal section housing connects between a pump and a motor. Upper and lower retainers at upper and lower ends of the housing have outward facing cylindrical walls. A bladder has an interior in fluid communication with dielectric lubricant in the motor. Rigid upper and lower sleeves are bonded within upper and lower openings of the bladder. The sleeves slide over the cylindrical walls of the retainers and are sealed by seal rings. Fasteners secure the sleeves to the cylindrical walls.

Abstract: An electrical connector for downhole well equipment has a housing having a cavity. A rigid rearward insulator is sealed within the cavity, the rearward insulator having a rearward insulator passage. An electrical conductor has an insulation layer and extends in a forward direction into the rearward insulator passage. An electrical connector terminal joins to a tip of the conductor. The insulation layer has a forward end spaced rearward from the connector terminal, defining an exposed portion of the conductor between the forward end of the insulation layer and the connector terminal. A grommet of resilient electrical insulation material within the rearward insulator passage has a grommet passage with a forward passage portion extending around the connector terminal and an intermediate passage portion sealing around the exposed portion. The grommet has an outer surface in sealing engagement with the rearward insulator passage.

Abstract: A submersible well pump assembly has a pump, a motor, and a tubular pressure equalizer housing located between the pump and the motor. A rotatable drive shaft extends within the housing on the axis for driving the pump. A guide tube surrounds the drive shaft, defining an inner annulus between the drive shaft and the guide tube and an outer annulus between the housing and the guide tube. A well fluid inlet path admits well fluid into the outer annulus. A hub assembly is pivotally mounted to the guide tube. The hub assembly has a communication passage with having at least one lateral portion extending away the axis and a communication passage opening spaced from the axis and in fluid communication with the outer annulus. The hub assembly has a counterweight that rotates the communication passage opening to a point above the axis while the axis is horizontal.

Abstract: An oil injection unit to provide motor oil to the motor of an electric submersible pump. The oil injection unit includes an injection module containing an amount of motor oil to be injected into the motor, a sensor to detect a predetermined condition that indicates the need to inject motor oil into the motor, and an injection valve that can be selectively opened to inject motor oil to the motor upon detection by the sensor of the predetermined condition.

Abstract: An oil injection unit to provide motor oil to the motor of an electric submersible pump.

Abstract: A centrifugal pump has a stationary diffuser with a bore. A thrust bearing has a tubular portion that inserts into the bore. The thrust bearing has an external shoulder that contacts a support surface in the bore of the diffuser for transmitting downward thrust from an upstream impeller to the diffuser. The thrust bearing has an internal shoulder for transmitting upward thrust from a downstream impeller to the diffuser.