Abstract: A submersible pumping system for use downhole, wherein the system includes a pump, a pump motor, a seal section, a shaft coupling the pump motor to the pump, a bearing assembly for axially retaining the shaft in place, and an electrical insulator for electrically isolating the pump bearing assembly from electrical current leaking from the motor and through the shaft. The electrical insulator can be made from polyetheretherketone, polyimide, polyketone, and mixtures thereof.

Abstract: Pressurized lubricant is used for stabilizing shaft bearings in an electrical submersible pump motor. A lubricant pump is located within the motor housing. The lubricant pump has a set of impellers attached to a lower end of the shaft and rotating with the shaft, the impellers being located in the flow path of the lubricant. A diffuser is located upstream of and adjacent each impeller. The impellers increase the radial velocity of the lubricant, and this velocity is converted into a pressure head at the impeller outlet. The lubricant flows through the first diffuser, through the first impeller, through the second diffuser, and then flows through the second impeller and out into a reservoir. The shaft has an axial flow passage with an outlet at each bearing. The outlet has at least three ports arranged symmetrically around the shaft for discharging lubricant into a clearance between the shaft and bearing to create a fluid film.

Abstract: Borehole instruments are powered by AC instrument power transmitted on all three phases of a power cable concurrently carrying three phase motor power, the instrument power transmitted at a multiple of the motor power frequency and having a corresponding fraction of the motor power voltage, and received via a capacitive coupling sufficient to withstand high-voltage cable insulation testing. The phase-to-neutral motor power provides approximately the same power level to the borehole instruments if a phase shorts to ground.

Abstract: Systems and methods for providing ride-through for interruptions in the power supplied to drives that are used to control equipment such as downhole submersible pumps. In one embodiment, a variable speed drive includes converter and inverter sections, a capacitor bank and a control system. The drive shuts down the converter section upon detecting a disruption in the AC input power and continues to generate output power by drawing on the energy stored in the capacitor bank. When the AC input power returns (or begins to return) to normal, the drive resumes operation of the converter section in a controlled manner (e.g., by presetting the firing angle of the SCR's in the converter to match the voltage across the capacitor bank.) The drive thereby limits the current that recharges the capacitor bank and prevents sudden inrushes of current that could damage the drive.

Abstract: A motor cooler for an electrical submersible pump (ESP). The ESP is typically deployed within casing and defines an annular space between the ESP and the casing. The ESP includes a pump having an intake, a motor cooler pump having an output port, a seal section below the motor cooler pump, and a motor located below a well inlet. Fluid is directed downwardly from the motor cooler pump output port to cool the motor. In one example, a shroud directs fluid received from the motor cooler pump output port downwardly past the motor and back up an outside of the shroud. In another example, longitudinal ribs direct flow in an annular space between the ESP and the casing. Fluid from the motor cooler pump output port is directed downwardly between adjacent ribs over a surface of the motor and then back up between another pair of ribs.

Abstract: A drive system for driving large capacity motors includes a motor and a variable frequency drive which accepts input from a three-phase power source. The drive system includes a step-up transformer, preferably of a high-capacity three-phase type, positioned between and electrically connected to the motor and the variable frequency drive to thereby step-up voltage received from the variable frequency drive to be supplied to the motor. The transformer includes a transformer chamber formed in the transformer tank containing a cooling fluid for cooling transformer internal components. A plurality of inductors forming part of a harmonic filter are positioned within the transformer chamber such that they can be protected from the environment and simultaneously cooled with other transformer internal components by the dielectric fluid. The filter includes capacitors that are preferably mounted outside of the tank.

Abstract: A drive system for driving large capacity motors includes a motor and a variable frequency drive which accepts input from a three-phase power source. The drive system includes a step-up transformer, preferably of a high-capacity three-phase type, positioned between and electrically connected to the motor and the variable frequency drive to thereby step-up voltage received from the variable frequency drive to be supplied to the motor. The transformer includes a transformer chamber formed in the transformer tank containing a cooling fluid for cooling transformer internal components. A plurality of inductors forming part of a harmonic filter are positioned within the transformer chamber such that they can be protected from the environment and simultaneously cooled with other transformer internal components by the dielectric fluid. The filter includes capacitors that are preferably mounted outside of the tank.

Abstract: A method and device are provided for stabilizing shaft bearings in a motor having a hollow shaft and holes communicating the shaft and the bearings. A lubricant pump is provided for pressurizing a volume of lubricant located within the motor housing, the pump having a set of impellers attached to a lower end of the shaft and rotating with the shaft, the impellers being located in the flow path of the lubricant. A diffuser is located upstream of and adjacent each impeller. The impellers increase the radial velocity of the lubricant, and this velocity is converted into a pressure head at the impeller outlet. The lubricant flows through the first diffuser, through the first impeller, through the second diffuser, and then flows through the second impeller and out into a reservoir. The pressure causes the lubricant to flow through the hollow shaft and through passages to stabilize the bearings.

Abstract: A pothead connector for an electrical submersible pump motor includes a housing. A first insulating block is disposed within the housing and has passages for receiving insulated conductors of the power cable. The passages in the first insulating block have counterbores on an second end. A second insulating block is also disposed within the housing. The second insulating block has passages through which the insulated conductors pass. The second insulating block also has protrusions on a first face that are concentric with the counterbores and shaped to fit within the counterbores in the first insulating block. An elastomeric washer is positioned within each of the counterbores. A fastener rigidly secures the second insulating block to the first insulating block, forcing the protrusions against the elastomeric washers to cause the washers to seal around the insulated conductors.

Abstract: A pothead connector for an electrical submersible pump motor includes a housing. A first insulating block is disposed within the housing and has passages for receiving insulated conductors of the power cable. The passages in the first insulating block have counterbores on an second end. A second insulating block is also disposed within the housing. The second insulating block has passages through which the insulated conductors pass. The second insulating block also has protrusions on a first face that are concentric with the counterbores and shaped to fit within the counterbores in the first insulating block. An elastomeric washer is positioned within each of the counterbores. A fastener rigidly secures the second insulating block to the first insulating block, forcing the protrusions against the elastomeric washers to cause the washers to seal around the insulated conductors.

Abstract: A sine wave filter including an inductor for each phase (three inductors) and three delta- or Y-connected capacitors is employed within a borehole power system, coupled within a three phase power system at the surface between the output of a variable frequency drive and a three phase power cable transmitting power to a borehole location, and boosts the output voltage of the drive. The sine wave filter is designed to have a resonant frequency higher than the maximum operational frequency of the drive, and a Q such that, at the maximum operational frequency of the drive, the filter provides a voltage gain equal to the ratio of the desired voltage to the drive's maximum output power at the maximum operational frequency. The sine wave filter also smooths the voltage waveform of a pulse width modulated variable frequency drive.

Abstract: A three phase power cable is employed to transmit data encoded in a phase-to-phase manner within a high frequency carrier signal transmitted simultaneously with power transmitted from surface equipment to downhole components. The high frequency carrier signal is transmitted on all conductors of the power cable, with the signal carried on at least two phases or conductors modulated between the two conductors to encode data between the two phases. Any modulation technique may be employed. Multiple phase-to-phase signals may be encoded and transmitted between different pairs of the power cable conductors, or the same data may be encoded and transmitted in multiple phase-to-phase signals in either a single-ended or differential manner. The high frequency carrier may be employed to transmit data from sensors downhole to the surface equipment, control signals from the surface equipment to the downhole components, or both.

Abstract: Arrangements are described wherein fluid is supplied under pressure to lubricate and replenish the fluid film located between the rotating, inner bearing sleeve and the outer, stationary sleeve insert of the bearing assemblies of a motor. The sleeve insert is provided with fluid metering passages that permit lubricating fluid to pass through the body of the sleeve insert. The sleeve insert is disposed radially within a sleeve insert holder, and a fluid gap is defined between the two components. During operation, vibration of the rotor shaft within the stator bore is damped by the fluid spring created by the metering of fluid through the sleeve insert. As a result, friction is reduced and the lifespan of the motor increased.

Abstract: A method and device are provided for stabilizing shaft bearings in a motor having a hollow shaft and holes communicating the shaft and the bearings. A lubricant pump is provided for pressurizing a volume of lubricant located within the motor housing, the pump having a set of impellers attached to a lower end of the shaft and rotating with the shaft, the impellers being located in the flow path of the lubricant. A diffuser is located upstream of and adjacent each impeller. The impellers increase the radial velocity of the lubricant, and this velocity is converted into a pressure head at the impeller outlet. The lubricant flows through the first diffuser, through the first impeller, through the second diffuser, and then flows through the second impeller and out into a reservoir. The pressure causes the lubricant to flow through the hollow shaft and through passages to stabilize the bearings.

Abstract: Arrangements are described wherein fluid is supplied under pressure to lubricate and replenish the fluid film located between the rotating, inner bearing sleeve and the outer, stationary sleeve insert of the bearing assemblies of a motor. The sleeve insert is provided with fluid metering passages that permit lubricating fluid to pass through the body of the sleeve insert. The sleeve insert is disposed radially within a sleeve insert holder, and a fluid gap is defined between the two components. During operation, vibration of the rotor shaft within the stator bore is damped by the fluid spring created by the metering of fluid through the sleeve insert. As a result, friction is reduced and the lifespan of the motor increased.

Abstract: A sine wave filter including an inductor for each phase (three inductors) and three delta- or Y-connected capacitors is employed within a borehole power system, coupled within a three phase power system at the surface between the output of a variable frequency drive and a three phase power cable transmitting power to a borehole location, and boosts the output voltage of the drive. The sine wave filter is designed to have a resonant frequency higher than the maximum operational frequency of the drive, and a Q such that, at the maximum operational frequency of the drive, the filter provides a voltage gain equal to the ratio of the desired voltage to the drive's maximum output power at the maximum operational frequency. The sine wave filter also smooths the voltage waveform of a pulse width modulated variable frequency drive.

Abstract: An improved electrical submersible pump is disclosed in which a processor downhole is utilized to monitor one or more subsurface conditions, to record data, and to alter at least one operating condition of the electrical submersible pump. Novel uses are described for downhole gas compression, the delivery of particulate matter to wellbore sites, and for the disposal of waste.

Abstract: A centrifugal well pump has modules of pumping stages, each module having a separate thrust bearing. The thrust bearing for each module is supported by an uppermost diffuser of the module. A thrust runner rotates with the shaft and engages the stationary thrust bearing. A tension member engages the runner and extends downward through the stages. The tension member has a number of upward facing load shoulders, one for each impeller within the module. Each of the load shoulders supports the hub of one of the impellers. Downthrust on each impeller transfers through the load shoulder to the tension member, and from there to the thrust runner.

Abstract: A motor for a submersible well pump has rotor sections spaced apart from each other with bearings located between. The bearings support the shaft of the rotor within a stator. The bearings have a body made up of thin, circular metal nonmagnetic disks. The disks are stacked axially. A resilient member mounts to the bearing body for engaging the inner wall of the stator to prevent rotation of the bearing.

Abstract: A cooling system for electrical components that includes a metal heat sink with parallel fins. An axial discharge fan is mounted across from the heat sink fins for discharging air against the fins. The fan has an axis that is perpendicular to the plane containing the fins so that the air strikes the fins at right angles.