A volumetric compensator assembly for use in the seal section of a pumping system includes an envelope bladder that in turn includes a flexible top sheet and a bottom sheet connected to the top sheet along a pair of side seams and an end seam. The top sheet and bottom sheet together define a bladder interior that has a variable capacity. The volumetric compensator assembly also has a bladder support tube and the envelope bladder is coiled around the bag support tube.

A well pump assembly includes a pump and a motor that contains a dielectric motor lubricant and a pressure equalizer containing a bellows. The bellows has an interior in fluid communication with the motor lubricant and an exterior immersed in well fluid. The bellows is axially extendable and contractible in response to a pressure differential between the well fluid and the motor lubricant. A tube has a lower end secured to a tube port in the pressure equalizer housing and an upper end secured to a lower end of the bellows. The tube has a center line that makes at least one curved flexible bend between the tube upper end and the tube lower end to enable the tube to flex as the bellows extends and contracts.

Disclosed is a pump having a pump rotor rotatably supported about an axis of rotation in a pump stator. In this respect, the pump rotor is designed and is arranged above a rotor shaft in a shaft bearing such that a lubricating film of a lubricating fluid formed from the pump fluid can be formed in a lubricating ring gap between the rotor shaft and the shaft bearing. In accordance with the invention, a separation device is provided at the rotor shaft by which a predefinable quantity of the ingredient can be separated from the pump fluid by means of a centrifugal force in the operating state for providing the lubricating fluid.

The invention provides an autonomous subsea barrier fluid system for a subsea pressure booster, the subsea pressure booster comprising a process fluid compartment, a motor compartment and a rotor assembly extending from the motor compartment into the process fluid compartment with one or several shaft seals separating the process fluid from the barrier fluid in the motor compartment. The subsea barrier fluid system is distinguished in that it comprises: a subsea barrier fluid pump, a barrier fluid delivery line, arranged between the barrier fluid pump and the motor compartment, a pressure controlled regulator, operatively arranged to at least one of the barrier fluid delivery line and the subsea barrier fluid pump, a subsea barrier fluid storage, and a barrier fluid suction line arranged from the subsea barrier fluid storage to the subsea barrier fluid pump.

A motor protector includes a housing and a rotatable shaft disposed within the housing and a plurality of radial bearings coupled to the rotatable shaft, for supporting the rotatable shaft against the housing. The motor protector further includes a thrust bearing coupled to the rotatable shaft, for supporting the rotatable shaft against the housing. The motor protector also includes a shaft seal coupled to the rotatable shaft, and configured to seal a first portion from a second portion of the housing. The motor protector also includes an isolation chamber, coupled substantially lateral to the housing and configured to separate a first fluid and a second fluid via the housing.

An electrical submersible pump assembly has modules including a pump, upper and lower tandem motors, and a pressure equalizer coupled to the motors. A thrust bearing support member is provided in the lower tandem motor and has a central counterbore with a thrust bearing located in the counterbore. Motor wire holes extend axially through the thrust bearing support member and are spaced radially outward from the counterbore. Motor wires of the lower tandem motor extend through the motor wire holes. A plurality of slots extend radially from the motor wire holes to the counterbore. Each of the slots have an axial length at least equal to an axial length of each of the motor wire holes, and a width greater than a diameter of each of the motor wires of the lower tandem motor.

An electrical submersible pump assembly has modules including a pump, at least one motor, and a pressure equalizer coupled to the motor. First and second ones of the modules have a threaded connection including a first adapter having threads. A second adapter mounted to the second module has a tubular body, a neck of smaller diameter than the body, an external shoulder at a base of the neck, a rim on the neck, and an external groove between the external shoulder and the rim. A collar is rotatably carried and axially movable on the neck, the collar being in threaded engagement with the threads of the first adapter, the collar having an internal groove. A split shoulder ring carried partly in the external groove and partly in the internal groove retains the collar on the neck and is biased into one of the grooves.

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.

A fluid system for a pump, which includes a downhole rotating shaft and bearings inside a housing, and where a fluid volume around shaft is circulated from outside housing through a filter, so that only clean non-abrasive fluid is permitted inside fluid volume pump to draw fluid around the shaft. A fluid expeller is included to expel fluid from the accumulated volume of fluid through the filter to purge the filter.

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.