Abstract: A well pump assembly has a barrel, a standing valve at an upper end of a standing valve chamber, and a plunger. A travelling valve admits well fluid into the barrel during a fill stroke. The travelling valve closes during a power stroke so that the plunger pushes well fluid from the barrel into the standing valve chamber. A gas release port extends from the standing valve chamber to the exterior of the pump assembly. A check valve in the gas release port has an outward flow blocking position for blocking liquid well fluid in the standing valve chamber from exiting through the gas release port while the plunger is in the power stroke. The cheek valve has a gas release position that enables gas present in the standing valve chamber to flow out the gas release port while the plunger is in the power stroke.

Abstract: A well pump assembly has a main pump suspended on a string of production tubing within casing in a well. A charge pump is located below the main pump. An annular sealing element between the charge pump intake and the charge pump discharge seals between the charge pump and the casing. A motor is coupled with the main pump and the charge pump. A bypass member has an open upper end above the main pump intake and a lower end above the sealing element. The bypass member defines a flow path from the discharge of the charge pump upward past the main pump intake, then downward to reach the main pump intake. The bypass member may be a bypass riser extending alongside the main pump, or it may be a shroud surrounding the main pump.

Abstract: An electrical submersible pump assembly has pump, motor and pressure equalizer modules. A first adapter, which secures to the first module, has an external set of first adapter threads. A second adapter, which secures to the second module, has an external set of second adapter threads. A collar has an internal set of collar first threads that engage the first adapter threads, and an internal set of collar second threads that engage the second adapter threads. The collar first and second threads differ from each other, such that rotation of the collar relative to the first and second modules pulls the first and second modules toward each other. The pitches of the collar first and second threads may differ. Or, the collar first and second threads may turn in opposite directions.

Abstract: An electrical submersible pump assembly has modules including a pump, a motor, and a pressure equalizer. A first adapter having threads is mounted to one of the modules. A second adapter is mounted to an adjacent one of the modules, the second adapter having a tubular body, a neck, and an external shoulder at a base of the neck. A collar is rotatably carried on the neck and in threaded engagement with the threads of the first adapter. A clamp secures around the neck between the external shoulder and the collar after the collar is fully engaged with the threads on the first adapter. A pair of flanges are mounted to and extend outward from the clamp. A motor lead locates between the flanges.

Abstract: An electrical submersible pump assembly includes a centrifugal pump having stages. Each of the stages has an impeller in cooperative engagement with a downstream diffuser. The impeller is axially movable relative to the downstream diffuser between a downthrust and an upthrust position. The downstream diffuser has an annular downstream wall surface, relative to the impeller, defining a downstream cavity. The impeller has a downstream balance ring that locates alongside the downstream wall surface. An annular clearance between the downstream balance ring and the downstream wall surface increases in response to the impeller moving from the downthrust to the upthrust position.

Abstract: A centrifugal well fluid pump has a pump intake and a pump discharge conduit extending upward from the pump. A barrier between the motor and the pump intake seals to casing in a well. A bypass tube extends from below the barrier, alongside the pump and has an outlet at an upper end of the pump. A riser surrounds the pump discharge conduit, the riser having a riser inlet in fluid communication with the bypass tube outlet. Liquid portions of the well fluid flow upward through the riser to discharge from the riser outlet and flow down to the pump intake. Gaseous portions of the well fluid flow upward through the riser and continue flowing upward into the casing.

Abstract: An electrical submersible pump assembly has a centrifugal primary pump having a primary pump housing. An electrical motor is operatively coupled to the primary pump. An instrument sub has a housing secured by threaded fasteners to one end of the primary pump housing. A pump stage in the instrument sub housing is driven by the electric motor along with the primary pump, the pump stage including an impeller and a diffuser. A sensor within the instrument sub monitors parameters in the instrument sub. A sensor line port extends through a wall of the instrument sub housing. A sensor line extends sealingly through the sensor line port to the sensor for conveying sensed information from the sensor to a remote instrument panel.

Abstract: A well pump assembly has a barrel, a standing valve at an upper end of a standing valve chamber, and a plunger. A travelling valve admits well fluid into the barrel during a fill stroke. The travelling valve closes during a power stroke so that the plunger pushes well fluid from the barrel into the standing valve chamber. A gas release port extends from the standing valve chamber to the exterior of the pump assembly. A check valve in the gas release port has an outward flow blocking position for blocking liquid well fluid in the standing valve chamber from exiting through the gas release port while the plunger is in the power stroke. The check valve has a gas release position that enables gas present in the standing valve chamber to flow out the gas release port while the plunger is in the power stroke.

Abstract: A well pump assembly has a main pump suspended on a string of production tubing within casing in a well. A charge pump is located below the main pump. An annular sealing element between the charge pump intake and the charge pump discharge seals between the charge pump and the casing. A motor is coupled with the main pump and the charge pump. A bypass member has an open upper end above the main pump intake and a lower end above the sealing element. The bypass member defines a flow path from the discharge of the charge pump upward past the main pump intake, then downward to reach the main pump intake. The bypass member may be a bypass riser extending alongside the main pump, or it may be a shroud surrounding the main pump.

Abstract: An electrical submersible pump (ESP) having a sleeve coupled to the shaft that rotates as the shaft rotates. The sleeve can be a base portion of a pump impeller, a journal bearing, or a bushing. A drive collar mounts around the shaft and has an end with a portion that projects past an end of the sleeve profiled to correspond with the shape of the projecting portion. As the shaft rotates the drive collar the projecting portion of the drive collar pushes against the profiled end of the sleeve to rotate the sleeve. The projecting portion can be a wedge shaped tab on the drive collar, or an angular segment of the drive collar extending axially past the remaining segments. The profiled end of the sleeve can include a recess formed to receive the tab and can have an angular segment corresponding to that on the drive collar.

Abstract: A centrifugal well fluid pump has a pump intake and a pump discharge conduit extending upward from the pump. A barrier between the motor and the pump intake seals to casing in a well. A bypass tube extends from below the barrier, alongside the pump and has an outlet at an upper end of the pump. A riser surrounds the pump discharge conduit, the riser having a riser inlet in fluid communication with the bypass tube outlet. Liquid portions of the well fluid flow upward through the riser to discharge from the riser outlet and flow down to the pump intake. Gaseous portions of the well fluid flow upward through the riser and continue flowing upward into the casing.

Abstract: An electrical submersible pump assembly includes a centrifugal pump having stages. Each of the stages has an impeller in cooperative engagement with a downstream diffuser. The impeller is axially movable relative to the downstream diffuser between a downthrust and an upthrust position. The downstream diffuser has an annular downstream wall surface, relative to the impeller, defining a downstream cavity. The impeller has a downstream balance ring that locates alongside the downstream wall surface. An annular clearance between the downstream balance ring and the downstream wall surface increases in response to the impeller moving from the downthrust to the upthrust position.

Abstract: An electrical submersible pump assembly has modules including a pump, a motor, and a pressure equalizer. A first adapter having threads is mounted to one of the modules. A second adapter is mounted to an adjacent one of the modules, the second adapter having a tubular body, a neck, and an external shoulder at a base of the neck. A collar is rotatably carried on the neck and in threaded engagement with the threads of the first adapter. A clamp secures around the neck between the external shoulder and the collar after the collar is fully engaged with the threads on the first adapter. A pair of flanges are mounted to and extend outward from the clamp. A motor lead locates between the flanges.

Abstract: An electrical submersible pump assembly has pump, motor and pressure equalizer modules. A first adapter, which secures to the first module, has an external set of first adapter threads. A second adapter, which secures to the second module, has an external set of second adapter threads. A collar has an internal set of collar first threads that engage the first adapter threads, and an internal set of collar second threads that engage the second adapter threads. The collar first and second threads differ from each other, such that rotation of the collar relative to the first and second modules pulls the first and second modules toward each other. The pitches of the collar first and second threads may differ. Or, the collar first and second threads may turn in opposite directions.

Abstract: An electrical submersible pump assembly has a centrifugal primary pump having a primary pump housing. An electrical motor is operatively coupled to the primary pump. An instrument sub has a housing secured by threaded fasteners to one end of the primary pump housing. A pump stage in the instrument sub housing is driven by the electric motor along with the primary pump, the pump stage including an impeller and a diffuser. A sensor within the instrument sub monitors parameters in the instrument sub. A sensor line port extends through a wall of the instrument sub housing. A sensor line extends sealingly through the sensor line port to the sensor for conveying sensed information from the sensor to a remote instrument panel.

Abstract: A submersible pumping system, electrical submersible pump, and method of providing enhanced alignment of motor and driven shafts of submersible pumping systems and electrical submersible pumps, are provided. An example of an electrical submersible pump system includes a pump, a pump motor, and a seal section. The motor drives the pump via motor and driven shafts rotatingly coupled with a coupling assembly. The coupling assembly maintains the shaft ends in coaxial alignment with an alignment device. The alignment device is profiled on opposite ends for mating engagement with the centering guides extending from the shaft ends.

Abstract: A seal section for use in a wellbore electrical submersible pump and includes an optic fiber detection arrangement wherein one or more optic fiber sensors is used to detect an operational parameter associated with the seal section. The operational parameters can include temperature, vibration and pressure.

Abstract: Devices and methods for detecting operational parameters associated with a gas separator used in an electric submersible pump in a wellbore. A fiber optic sensing arrangement is used to detect the operational parameter and includes a fiber optic signal processor and an optic fiber that is associated with the gas separator to provide a signal indicative of the parameter to the signal processor.

Abstract: A centrifugal pump has alternating impellers and diffusers. One or more vent holes extend through one or more vanes of one or more diffusers. In an upthrust condition, high pressure production fluid from an upper impeller is able to pass through the one or more vent holes, and thereby exert force on the preceding impeller. The force exerted on the preceding impeller offsets the upthrust force acting against the preceding impeller.

Abstract: A seal section for use in a wellbore electrical submersible pump and includes an optic fiber detection arrangement wherein one or more optic fiber sensors is used to detect an operational parameter associated with the seal section. The operational parameters can include temperature, vibration and pressure.