Abstract: A seal section for use in a downhole submersible pumping system includes a lower chamber, an upper chamber and an intermediate guide section between the lower chamber and the upper chamber. The lower chamber includes a seal bag assembly that has a seal bag containing motor oil and an exterior space around the seal bag that contains high density oil that is denser than the motor oil. The upper chamber includes a volume of the high density oil at the bottom of the upper chamber and a gravity trap connected to the exterior space through an intermediate passage in the intermediate guide section. The gravity trap includes an opening submerged in the volume of high density oil in the upper chamber.

Abstract: A fixture has a body that connects to a motor, the body having a bore. The body has a piston in the bore, separating the bore into a pressure chamber and a lubricant chamber in fluid communication with lubricant in the motor. A technician applies pressure to the pressure chamber, which causes the piston to increase pressure of the lubricant in the lubricant chamber and in the motor. The technician monitors a distance of movement of the piston, indicating a presence of residual air in the lubricant. If the movement meets a amount, the technician applies a vacuum to the lubricant chamber and bleeds out residual air from the lubricant in the motor.

Abstract: A fixture has a body that connects to a motor, the body having a bore. The body has a piston in the bore, separating the bore into a pressure chamber and a lubricant chamber in fluid communication with lubricant in the motor. A technician applies pressure to the pressure chamber, which causes the piston to increase pressure of the lubricant in the lubricant chamber and in the motor. The technician monitors a distance of movement of the piston, indicating a presence of residual air in the lubricant. If the movement meets a amount, the technician applies a vacuum to the lubricant chamber and bleeds out residual air from the lubricant in the motor.

Abstract: A fixture has a body that connects to a motor, the body having a bore. The body has a piston in the bore, separating the bore into a pressure chamber and a lubricant chamber in fluid communication with lubricant in the motor. A technician applies pressure to the pressure chamber, which causes the piston to increase pressure of the lubricant in the lubricant chamber and in the motor. The technician monitors a distance of movement of the piston, indicating a presence of residual air in the lubricant. If the movement meets a amount, the technician applies a vacuum to the lubricant chamber and bleeds out residual air from the lubricant in the motor.

Abstract: A seal section of a submersible well pump assembly has an expandable and contractible bag surrounded by a pressure equalizing chamber. A motor lubricant communication path communicates motor lubricant the bag interior. A well fluid port admits well fluid into the pressure equalizing chamber. A gas vent passage leads from the pressure equalizing chamber to the exterior of the enclosure. At least one membrane in the gas vent passage allows gas contained in the well fluid in the pressure equalizing chamber to vent. The membrane blocks liquid from flowing through the gas vent passage into and out of the pressure equalizing chamber.

Abstract: A fixture has a body that connects to a motor, the body having a bore. The body has a piston in the bore, separating the bore into a pressure chamber and a lubricant chamber in fluid communication with lubricant in the motor. A technician applies pressure to the pressure chamber, which causes the piston to increase pressure of the lubricant in the lubricant chamber and in the motor. The technician monitors a distance of movement of the piston, indicating a presence of residual air in the lubricant. If the movement meets a amount, the technician applies a vacuum to the lubricant chamber and bleeds out residual air from the lubricant in the motor.

Abstract: A seal section of a submersible well pump assembly has an expandable and contractible bag surrounded by a pressure equalizing chamber. A motor lubricant communication path communicates motor lubricant the bag interior. A well fluid port admits well fluid into the pressure equalizing chamber. A gas vent passage leads from the pressure equalizing chamber to the exterior of the enclosure. At least one membrane in the gas vent passage allows gas contained in the well fluid in the pressure equalizing chamber to vent. The membrane blocks liquid from flowing through the gas vent passage into and out of the pressure equalizing chamber.

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: A submersible well pump assembly includes a seal unit coupled between a pump and a motor. The seal unit has a forward guide member, a rearward guide member, and a labyrinth disc chamber connected between. The labyrinth disc chamber has an outer wall, a concentric guide tube and a number of axially spaced apart discs extending between the guide tube and the outer wall, defining cavities between the discs. Disc ports extend through the discs to communicate fluid between the cavities, the ports being at multiple angular locations relative to each other. A drive shaft extends through the guide tube, the forward guide member bore and the rearward guide member. The outer wall, the guide tube and the discs are made of a single-piece member.

Abstract: A submersible well pump assembly has upper and lower seal sections connected between the pump and a motor. The seal sections have drive shafts with thrust runners that engage thrust bearing bases. The upper drive shaft will undergo a limited amount of downward movement toward the lower drive shaft in response to wear of the upper thrust bearing base. A spring between ends of the drive shafts transfers a portion of the down thrust on the upper drive shaft to the lower drive shaft prior to the limited amount of downward movement of the upper drive shaft toward the lower drive shaft being reached. A rigid stop member in the coupling transfers down thrust directly from the upper drive shaft to the lower drive shaft, bypassing the spring, only after the limited amount of downward movement of the upper drive shaft toward the lower drive shaft has been reached.

Abstract: An electrical submersible pump assembly has a seal section housing for coupling between a motor and a pump of the assembly. A bladder has an opening sized to slide over an adapter in the seal section housing. A clamp ring is formed of a shape memory alloy selected to create an expanded condition inner diameter when at a room temperature, enabling the clamp ring to be inserted over the bladder opening during assembly. When heated to a selected elevated temperature, the clamp ring contracts and tightly secures the opening around the adapter. The shape memory alloy of the clamp ring also causes the contracted condition inner diameter to expand when chilled to a selected low temperature.

Abstract: A submersible well pump is driven by an electrical motor. A thrust bearing module between the pump and the motor has a base secured to and extending downward from a housing. The base has a motor end connector and an axial bore in fluid communication with lubricant in the motor. A shaft extends through the bore and into the housing. A thrust bearing assembly has a lower end at an upper end of the base. A lubricant pump mounted in the bore and coupled to the shaft pumps lubricant upward into the chamber. A passage has an inlet port in the chamber and an outlet port within the bore for returning lubricant pumped by the lubricant pump. The passage extends internally through the base and has a number of turns encircling the bore.

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: A submersible well pump is driven by an electrical motor. A thrust bearing module between the pump and the motor has a base secured to and extending downward from a housing. The base has a motor end connector and an axial bore in fluid communication with lubricant in the motor. A shaft extends through the bore and into the housing. A thrust bearing assembly has a lower end at an upper end of the base. A lubricant pump mounted in the bore and coupled to the shaft pumps lubricant upward into the chamber. A passage has an inlet port in the chamber and an outlet port within the bore for returning lubricant pumped by the lubricant pump. The passage extends internally through the base and has a number of turns encircling the bore.

Abstract: A submersible well pump assembly includes a seal unit coupled between a pump and a motor. The seal unit has a forward guide member, a rearward guide member, and a labyrinth disc chamber connected between. The labyrinth disc chamber has an outer wall, a concentric guide tube and a number of axially spaced apart discs extending between the guide tube and the outer wall, defining cavities between the discs. Disc ports extend through the discs to communicate fluid between the cavities, the ports being at multiple angular locations relative to each other. A drive shaft extends through the guide tube, the forward guide member bore and the rearward guide member. The outer wall, the guide tube and the discs are made of a single-piece member.

Abstract: A submersible well pump assembly has upper and lower seal sections connected between the pump and a motor. The seal sections have drive shafts with thrust runners that engage thrust bearing bases. The upper drive shaft will undergo a limited amount of downward movement toward the lower drive shaft in response to wear of the upper thrust bearing base. A spring between ends of the drive shafts transfers a portion of the down thrust on the upper drive shaft to the lower drive shaft prior to the limited amount of downward movement of the upper drive shaft toward the lower drive shaft being reached. A rigid stop member in the coupling transfers down thrust directly from the upper drive shaft to the lower drive shaft, bypassing the spring, only after the limited amount of downward movement of the upper drive shaft toward the lower drive shaft has been reached.

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.