Abstract: Systems and methods for preventing rotation of rotor bearings in electric motors which enable retrofitting of conventionally designed bearings to use spring-loaded keys instead of elastomeric T-rings to prevent rotation while allowing axial movement of the bearings within a stator bore. An elongated, curved spring arm is positioned in the nesting groove at the outer periphery of the bearing. One end of the spring may be secured to the bearing by positioning an S-shaped bend in the spring arm through a hole in the floor of the nesting groove. A key at the opposite end of the spring arm is urged radially outward by the spring arm. The key may be positioned in a slot in the outer portion of the bearing, and the spring arm may be retained in the groove by a retaining pin installed in the groove.

Abstract: A submersible well pump motor has features to prevent the carrier bearing from sliding axially along the stator due to thermal growth of the rotor. The rotor has a shaft and rotor sections spaced apart from each other. Carrier bearings are located between the rotor sections, each having an anti-rotation member that frictionally engages the inner diameter of the stator to prevent spinning of the carrier bearing. A deflectable thrust washer may be located between ends of the carrier bearing and the rotor sections. The thrust washer reduces in thickness in response to an axial thermal growth force due to axial thermal growth movement of the rotor sections and shaft. The thermal growth force is less than an amount of dislodging force required to cause the anti-rotation member to axially move relative to the stator. Rather than deflectable thrust washers, sacrificial thrust washers that dissolve prior to normal operation may be used.

Abstract: A well pump includes a plunger reciprocally carried within a barrel between up stroke and down stroke positions. A tubular linear actuator housing located below the barrel has a rotatable rotor. An array of rotor magnets is mounted to the rotor, directing rotor magnetic fields in an outward direction. A cage is fixed against rotation relative to the housing and carried within the housing for axial movement relative to the rotor and the housing. The cage has a cylindrical inner sidewall surrounding the outer sidewall of the rotor. An array of cage magnets is mounted to the inner sidewall of the cage. The cage magnets direct cage magnetic fields in an inward direction relative to the axis. The cage and rotor magnetic fields interact such rotation of the rotor causes axial movement of the cage. A motor rotates the rotor.

Abstract: Systems and methods for providing moisture-proof seals around the splices in an ESP motor. Two-layer encapsulation around each splice includes an outer layer of heat-shrink material that shrinks at a first temperature, and an inner layer of insulating material that melts at a temperature below the first temperature. The encapsulation materials are positioned around the electrical junction of the splice and heated. As the temperature reaches the melting temperature of the inner material, this material melts. As the temperature reaches the temperature at which the outer layer begins to shrink, the outer layer presses softened material of the inner layer against the conductors and the wire insulation near the splice, thereby conforming the material of the inner layer to the magnet wires at the splice and forming a moisture-proof barrier. Similarly constructed splices can connect motor lead extensions to the stator windings and form a Y-point of the motor.

Abstract: Systems and methods for connecting power cables to downhole equipment such as ESPs using side-exit (radial) connections. In one embodiment, a system includes an electric drive coupled by a power cable to an ESP. The electric drive is positioned at the surface of a well with the power cable coupled to it. The power cable extends into the well bore and is coupled to the downhole equipment which is positioned in the well bore. The power cable has a connector with a first set of radially oriented terminals (the terminals are perpendicular to the conductors of the power cable). These terminals engage a second set of terminals that are installed in the downhole equipment. The radial orientation of the terminals of the connector and downhole equipment allow the power cable to remain axially oriented, thereby facilitating engagement of the terminals and requiring less annular space in the well bore.

Abstract: An electric submersible pump (ESP) system that is installed in a well to lift fluids out of the well. In one embodiment, the system includes an electric drive positioned at the surface of a well, an ESP positioned downhole in the well, and a cable coupled to carry power from the drive to the ESP. The ESP has a motor that may be either a rotary or linear motor. The stator has magnet coils that may be formed by carbon nanotube conductors. In an inductive rotary motor, carbon nanotube conductors to form the rotor bars and/or conductive end plates of the rotor. The power cable coupling the electric drive to the ESP motor may use carbon nanotube conductors to carry power to the motor, and may also use carbon nanotube strength members to carry the weight of the cable and ESP.

Abstract: Systems and methods for preventing rotation of rotor bearings in electric motors which enable retrofitting of conventionally designed bearings to use spring-loaded keys instead of elastomeric T-rings to prevent rotation while allowing axial movement of the bearings within a stator bore. An elongated, curved spring arm is positioned in the nesting groove at the outer periphery of the bearing. One end of the spring may be secured to the bearing by positioning an S-shaped bend in the spring arm through a hole in the floor of the nesting groove. A key at the opposite end of the spring arm is urged radially outward by the spring arm. The key may be positioned in a slot in the outer portion of the bearing, and the spring arm may be retained in the groove by a retaining pin installed in the groove.

Abstract: Systems and methods for configuring stators for downhole electric motors, where a single master stator can be configured to function as multiple different types of stators. In one embodiment, a configurable stator has a plurality of magnet windings disposed within its body, wherein the windings are connected to a plurality of electrical terminals that are accessible from the exterior of the body of the stator. Each of the terminals is configured to enable any one of a plurality of different types of lead wires to be attached to it, thereby enabling the stator to be configured in various different ways. In one embodiment, the master stator can be configured as a single stator, an upper tandem stator, a middle tandem stator, or a lower tandem stator.

Abstract: Systems and methods for the construction of electric motors, where expandable material is inserted into the slots in which magnet wires are positioned and expanded in the slots to mechanically restrain the wires. One embodiment comprises a downhole electric motor such as might be used in an electric submersible pump (ESP) system. The motor has a stator with multiple slots in which magnet wires are positioned. A slot liner is positioned in each slot and an expansion pad is positioned in each slot between the slot liner and the slot wall nearest the bore of the stator. The wires are positioned inside the slot liner. When the motor is almost completely assembled, it is filled with oil. Some of the oil is absorbed by the expansion pads, which then expand to fill the unoccupied volume in the slots, thereby restraining the movement of the wires within the slots.

Abstract: A submersible well pump assembly include a rotary pump driven by an electrical motor. A seal section operably connects between the motor and the pump for reducing a pressure differential between motor oil in the motor and well fluid surrounding the pump assembly. The pump assembly contains a sealed fluid. A sensor mounted to the well pump assembly detects contamination of the sealed fluid by well fluid encroaching into contact with the sealed fluid. The sensor may be mounted in the motor or the seal section to detect well fluid contamination of motor oil. The sensor may be mounted in a secondary pump that has that has temporary barriers to block the entry of well fluid into a buffer fluid contained in the secondary pump while the secondary pump is in a storage condition within a well.

Abstract: Systems and methods for monitoring partial discharge within a remotely located and inaccessible electric motor. One embodiment comprises a downhole electric motor of an electric submersible pump system positioned in a well. The motor includes a partial discharge monitoring system coupled to the motor's power terminals. The partial discharge monitoring system includes a filter subsystem, a processing subsystem, and a communication subsystem. The filter subsystem allows higher frequency signals to pass from the terminals to the processing subsystem. The processing subsystem identifies signal constituents that are associated with partial discharge, and may perform various types of processing or analysis of the signal received from the processing subsystem. The partial discharge information generated by the processing subsystem is passed to the communication subsystem, which communicates the information to remotely located surface equipment.

Abstract: A submersible well pump motor has features to prevent the carrier bearing from sliding axially along the stator due to thermal growth of the rotor. The rotor has a shaft and rotor sections spaced apart from each other. Carrier bearings are located between the rotor sections, each having an anti-rotation member that frictionally engages the inner diameter of the stator to prevent spinning of the carrier bearing. A deflectable thrust washer may be located between ends of the carrier bearing and the rotor sections. The thrust washer reduces in thickness in response to an axial thermal growth force due to axial thermal growth movement of the rotor sections and shaft. The thermal growth force is less than an amount of dislodging force required to cause the anti-rotation member to axially move relative to the stator. Rather than deflectable thrust washers, sacrificial thrust washers that dissolve prior to normal operation may be used.

Abstract: A submersible well pump motor has features to prevent the carrier bearing from sliding axially along the stator due to thermal growth of the rotor. The rotor has a shaft and rotor sections spaced apart from each other. Carrier bearings are located between the rotor sections, each having an anti-rotation member that frictionally engages the inner diameter of the stator to prevent spinning of the carrier bearing. A deflectable thrust washer may be located between ends of the carrier bearing and the rotor sections. The thrust washer reduces in thickness in response to an axial thermal growth force due to axial thermal growth movement of the rotor sections and shaft. The thermal growth force is less than an amount of dislodging force required to cause the anti-rotation member to axially move relative to the stator. Rather than deflectable thrust washers, sacrificial thrust washers that dissolve prior to normal operation may be used.

Abstract: Systems and methods for the construction of electric motors, where expandable material is inserted into the slots in which magnet wires are positioned and expanded in the slots to mechanically restrain the wires. One embodiment comprises a downhole electric motor such as might be used in an electric submersible pump (ESP) system. The motor has a stator with multiple slots in which magnet wires are positioned. A slot liner is positioned in each slot and an expansion pad is positioned in each slot between the slot liner and the slot wall nearest the bore of the stator. The wires are positioned inside the slot liner. When the motor is almost completely assembled, it is filled with oil. Some of the oil is absorbed by the expansion pads, which then expand to fill the unoccupied volume in the slots, thereby restraining the movement of the wires within the slots.

Abstract: Systems and methods for constructing electric motors in which a stator core includes inner and outer portions that enable slots for magnet windings to be open during construction and closed in the completed motor. One embodiment comprises a method in which an inner stator core having a plurality of slots is formed by stacking a set of laminations. The slots are open radially outward from an axis of the inner stator core and which are configured to accommodate turns of magnet wire. After the magnet wire is positioned in the open slots, an outer stator core comprising stacked laminations is positioned around the inner stator core, enclosing the slots. The inner and outer stator cores are then positioned within a housing and assembled into a downhole motor.

Abstract: Systems and methods for monitoring partial discharge within a remotely located and inaccessible electric motor. One embodiment comprises a downhole electric motor of an electric submersible pump system positioned in a well. The motor includes a partial discharge monitoring system coupled to the motor's power terminals. The partial discharge monitoring system includes a filter subsystem, a processing subsystem, and a communication subsystem. The filter subsystem allows higher frequency signals to pass from the terminals to the processing subsystem. The processing subsystem identifies signal constituents that are associated with partial discharge, and may perform various types of processing or analyses of the signal received from the processing subsystem. The partial discharge information generated by the processing subsystem is passed to the communication subsystem, which communicates the information to remotely located surface equipment.

Abstract: Systems and methods for configuring stators for downhole electric motors, where a single master stator can be configured to function as multiple different types of stators. In one embodiment, a configurable stator has a plurality of magnet windings disposed within its body, wherein the windings are connected to a plurality of electrical terminals that are accessible from the exterior of the body of the stator. Each of the terminals is configured to enable any one of a plurality of different types of lead wires to be attached to it, thereby enabling the stator to be configured in various different ways. In one embodiment, the master stator can be configured as a single stator, an upper tandem stator, a middle tandem stator, or a lower tandem stator.

Abstract: Systems and methods for reducing or preventing partial discharge between turns of a single coil within an electric motor by placing insulating barriers between different pluralities of wire turns in a single coil. One embodiment comprises an electric motor. The motor includes a rotor and a stator, where the stator has multiple coils of wire that are positioned in passageways in the stator to form electromagnets. Each wire coil has multiple wire turns, and insulating barriers are positioned between different sets of wire turns within the coil. In one embodiment, the stator includes a slot liner in each passageway to electrically isolate all of the wire turns in each coil from the walls of the passageway. The wire coils may be formed with wire that has an insulating coating which is separate from the insulating barriers.

Abstract: A submersible well pump motor has features to prevent the carrier bearing from sliding axially along the stator due to thermal growth of the rotor. The rotor has a shaft and rotor sections spaced apart from each other. Carrier bearings are located between the rotor sections, each having an anti-rotation member that frictionally engages the inner diameter of the stator to prevent spinning of the carrier bearing. A deflectable thrust washer may be located between ends of the carrier bearing and the rotor sections. The thrust washer reduces in thickness in response to an axial thermal growth force due to axial thermal growth movement of the rotor sections and shaft. The thermal growth force is less than an amount of dislodging force required to cause the anti-rotation member to axially move relative to the stator. Rather than deflectable thrust washers, sacrificial thrust washers that dissolve prior to normal operation may be used.

Abstract: An electrical submersible pump assembly has a motor cooperatively engaged with a pump for driving the pump and a motor lead extending to the motor for supplying power to the motor. The motor lead has an electrical conductor enclosed within a tube. The tube is sealed from an exterior environment of the motor and contains a dielectric fluid. The motor may be filled with a dielectric lubricant and the interior of the tube of the motor lead may be in fluid communication with the dielectric lubricant. Alternatively, the motor may filled with a dielectric lubricant and the dielectric fluid within the interior of the tube of the motor lead may be sealed from the dielectric lubricant.