Abstract: A coil assembly of a seal-less pump or turbine comprises materials having differing coefficients of thermal expansion that are layered but not bonded together, thereby reducing thermal stresses at cryogenic temperatures. Differences in shrinkage upon cooling provides compressive structural support. Coils are wound on hollow, non-magnetic spools, and a resin is applied for mechanical support, for example by vacuum impregnation. A release agent prevents bonding of the resin to the coils. The hollow spools are then placed over winding cores, such as laminated iron cores, without bonding. During cooling, the non-metallic spools shrink more than the cores, thereby providing compression fits. At ambient temperature, the spools can be held in place by interferences fits, and/or by key-stock pieces. Wired interconnections between the coils can be located within a wire harness cavity, which can be filled with a resin to provide mechanical support, while a release agent prevents bonding.

Abstract: An axial direct drive integral motor pump (IMP) or integral motor turbine (IMT) includes a stator or impeller housing hermetically sealed in front by a cover plate. At least one port in a housing rear face enables a barrier material, such as a resin, to be injected into the housing after attachment of the cover plate, so that the barrier material abuts the cover plate with substantially no gap therebetween. The barrier plate is thereby protected from undue deformation and damage by a pressurized process fluid. The barrier material can be injected through one or more fill ports by vacuum impregnation, and/or displaced air can escape through one or more drain ports. The ports can be sealed by plugs. The ports and plugs can be threaded and/or tapered. The coefficient of thermal expansion (CTE) of the barrier material can be substantially equal to a CTE of the first housing.

Abstract: An integral motor pump (IMP) or integral motor turbine (IMT) includes an axial field permanent magnet synchronous motor (PMSM) having a stator that is sealed by a disk-shaped non-conducting stator cover axially interposed between the stator and PMSM impeller, such that eddy currents are not generated in the stator cover by the rotating permanent magnets of the impeller. The stator cover can be annular, and can be fixed directly to the stator housing, or pressed against the stator housing by brackets. The seal can be formed by an adhesive, and/or by at least one gasket. Either the stator cover or the brackets can include flanges extending axially proximate the stator housing, and attached to the stator housing by any combination of an interference fit, an adhesive, set screws, or a protrusion extending into an indentation. In embodiments, the bracket flanges are welded to the stator housing.

Abstract: Axial bearing wear of a directly driven, axial, integral motor pump (IMP) or integral motor turbine (IMT) is monitored without use of sensors by estimating an axial rotor-stator gap according to a known dependence of the back EMF on the impeller rotation rate and the rotor-stator gap. The back EMF can be directly measured, for example between impulses of a variable frequency drive (VFD), or inferred from measurements of voltage applied to IMP stator coils and the resulting current. The rotation rate of an IMT impeller can be determined from a modulation frequency of the EMF. The rotation rate of an IMP impeller can be inferred due to its synchronicity with the applied, amplitude modulated power. A controller can record and report rotor-stator gap estimates over time, and can halt operation of the module if the estimated rotor-stator gap falls outside of a specified range.

Abstract: A system and method of pumping low-density liquids, such as liquid hydrogen (LH2), includes a plurality of integrated motor/pump modules (IMPs) interconnected in series, each having a single IMP impeller. A controller separately adjusts the speeds of the IMP impellers such that a specified head of the pumping system is achieved, while a critical NPSH_c of each IMP remains below its NPSH_A. The IMPs can be identical, and the controller can cause all of the impellers to rotate at the same speed, except for any that require a speed reduction to ensure that its NPSH_c remains below its NPSH_A. The IMPs can comprise induction coils or permanent magnets attached to the impellers that pass in proximate radial or axial alignment with stator coils. The IMPs can be controlled by variable frequency drives (VFDs). A cooling system can transfer heat from within the IMP to an external heat destination.

Abstract: Systems and methods for preventing rotation of an ESP motor when the motor is not powered on, thereby preventing the motor from acting as a generator when fluid flowing through the pump section of the ESP applies a torque to the motor. In one embodiment, an ESP has a motor section, a pump section. The ESP may include a directional coupling that allows unidirectional rotation between the motor shaft and a pump shaft of the pump section, and a directional lock that allows unidirectional rotation between the motor shaft and a housing of the motor section. The directional coupling and directional lock allow the pump shaft to freewheel in the forward direction without causing the motor shaft to rotate, and prevent the pump shaft and motor from rotating in the reverse direction.

Abstract: Systems and methods for preventing rotation of an ESP motor when the motor is not powered on, thereby preventing the motor from acting as a generator when fluid flowing through the pump section of the ESP applies a torque to the motor. In one embodiment, an ESP has a motor section, a pump section. The ESP may include a directional coupling that allows unidirectional rotation between the motor shaft and a pump shaft of the pump section, and a directional lock that allows unidirectional rotation between the motor shaft and a housing of the motor section. The directional coupling and directional lock allow the pump shaft to freewheel in the forward direction without causing the motor shaft to rotate, and prevent the pump shaft and motor from rotating in the reverse direction.

Abstract: An electrical submersible pump (ESP) isolates its motor lubricant from pumped product without requiring a bellows, diaphragm, bladder, or external lubricant pressurizing system. A pair of nested isolation chambers below the motor housing are filled with a barrier fluid that is non-reactive, non-miscible, and higher in density than the pumped product and the motor lubricant. As the motor lubricant expands and contracts after pump start-up and shut-down, motor lubricant and barrier fluid are exchanged between the motor housing and the isolation chambers via three interconnections, while pumped product is exchanged with the inner barrier chamber, while being isolated from the motor housing. The interconnections extend between the bottom of the motor housing and the bottom of the outer barrier chamber, between the top of the outer barrier chamber and the bottom of the inner barrier chamber, and between the top of the inner barrier chamber and the pumped product.

Abstract: An electrical submersible pump (ESP) isolates its motor lubricant from pumped product without requiring a bellows, diaphragm, bladder, or external lubricant pressurizing system. A pair of nested isolation chambers below the motor housing are filled with a barrier fluid that is non-reactive, non-miscible, and higher in density than the pumped product and the motor lubricant. As the motor lubricant expands and contracts after pump start-up and shut-down, motor lubricant and barrier fluid are exchanged between the motor housing and the isolation chambers via three interconnections, while pumped product is exchanged with the inner barrier chamber, while being isolated from the motor housing. The interconnections extend between the bottom of the motor housing and the bottom of the outer barrier chamber, between the top of the outer barrier chamber and the bottom of the inner barrier chamber, and between the top of the inner barrier chamber and the pumped product.

Abstract: A string of coiled tubing having a power cable therein supports and supplies power to an electrical submersible well pump assembly in a well. The coiled tubing has an upper section and a lower section joining each other, the upper section having a smaller inner diameter than the lower section. The power cable has an upper portion installed in the upper section of the coiled tubing and a lower portion installed in the lower section of the coiled tubing. The power cable has three insulated electrical conductors embedded within an elastomeric jacket. A metal armor strip has turns wrapped helically around the jacket. The armor strip is compressed between the jacket and the coiled tubing both in the upper section and in the lower section of the coiled tubing.

Abstract: Systems and methods for preventing rotation of an ESP motor when the motor is not powered on, thereby preventing the motor from acting as a generator when fluid flowing through the pump section of the ESP applies a torque to the motor. In one embodiment, an ESP has a motor section, a pump section. The ESP may include a directional coupling that allows unidirectional rotation between the motor shaft and a pump shaft of the pump section, and a directional lock that allows unidirectional rotation between the motor shaft and a housing of the motor section. The directional coupling and directional lock allow the pump shaft to freewheel in the forward direction without causing the motor shaft to rotate, and prevent the pump shaft and motor from rotating in the reverse direction.

Abstract: A downhole well pump assembly includes a pump and a motor. The motor has a motor housing with a motor head adapter on one end, the motor head adapter having a threaded connector. A seal section seals around a shaft of the motor, the seal section having a seal section adapter connected to the motor head adapter with the threaded connector. The motor head adapter and the motor housing have cylindrical exterior surfaces and end faces that face each other, defining a joint between the end faces. A first strip of metal foil is welded around the exterior surfaces of the motor head adapter and the motor housing at the joint, sealing the entry of well fluids into the joint.

Abstract: A string of coiled tubing having a power cable therein supports and supplies power to an electrical submersible well pump assembly in a well. The coiled tubing has an upper section and a lower section joining each other, the upper section having a smaller inner diameter than the lower section. The power cable has an upper portion installed in the upper section of the coiled tubing and a lower portion installed in the lower section of the coiled tubing. The power cable has three insulated electrical conductors embedded within an elastomeric jacket. A metal armor strip has turns wrapped helically around the jacket. The armor strip is compressed between the jacket and the coiled tubing both in the upper section and in the lower section of the coiled tubing.

Abstract: A downhole well pump assembly includes a pump and a motor. The motor has a motor housing with a motor head adapter on one end, the motor head adapter having a threaded connector. A seal section seals around a shaft of the motor, the seal section having a seal section adapter connected to the motor head adapter with the threaded connector. The motor head adapter and the motor housing have cylindrical exterior surfaces and end faces that face each other, defining a joint between the end faces. A first strip of metal foil is welded around the exterior surfaces of the motor head adapter and the motor housing at the joint, sealing the entry of well fluids into the joint.

Abstract: An electrical submersible pumping system includes a well fluid pump driven by a three-phase motor. The motor has a stack of motor laminations mounted in a housing. The motor laminations have axially aligned slots spaced circumferentially around a bore. Motor windings are wound through the slots for receiving three-phase power provided to the motor. At least one set of three control lines extend axially through the motor laminations radially outward from the bore and equally spaced around the axis, The control lines may extend through channels on the outer diameter of the motor laminations. The control lines may also extend through the same slots that contain the windings. The control lines extend to a downhole element below the motor for controlling the downhole element.

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: Systems and methods for constructing electric motors including both permanent magnet elements and inductive elements. In one embodiment, a motor is implemented of an ESP system has multiple rotor sections that are mounted end-to-end within the bore of the stator. The permanent magnet elements and inductive elements may be combined within individual rotor sections, or they may be segregated so that one rotor section has only one type or the other. The inductive elements of the rotor allow the motor to be started without a VFD, and without knowing the position of the rotor within the motor. The permanent magnet elements synchronize the rotor with the rotating stator fields when the rotor approaches the operating frequency of the drive.

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: An electrical submersible pumping system includes a well fluid pump driven by a three-phase motor. The motor has a stack of motor laminations mounted in a housing. The motor laminations have axially aligned slots spaced circumferentially around a bore. Motor windings are wound through the slots for receiving three-phase power provided to the motor. At least one set of three control lines extend axially through the motor laminations radially outward from the bore and equally spaced around the axis, The control lines may extend through channels on the outer diameter of the motor laminations. The control lines may also extend through the same slots that contain the windings. The control lines extend to a downhole element below the motor for controlling the downhole element.

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.