Abstract: A system for determining whether a motor in an electrical submersible pump is backspinning is described herein. The system comprises a sensor mounted in a well bore proximate to a ground surface, the sensor outputting a backspin signal; a communication link connected to the sensor, the communications link communicating the backspin signal; and a controller receiving the backspin signal from the communications link and processing the backspin signal to determine whether the motor is backspinning.

Abstract: An electrical submersible pumping assembly having a seal section and a motor section, and seals that prevent leakage from the seal section and the motor section during assembly. The seals cooperate with a coupling assembly for coupling together shafts from both the seal section and motor section. The coupling assembly outer diameter enlarges at a shoulder that circumscribes its outer surface. In one example, the seal that prevents leakage from the seal assembly provides a sealing interface around the larger diameter portion of the coupling assembly, that is removable by sliding the coupling so its smaller diameter portion is adjacent the seal assembly. The motor section is sealed by another sealing assembly that includes a body that circumscribes the motor shaft to define an annulus, a sealing disk selectively fills the annulus. The sealing disk can also be slid away from within the body while coupling the shafts with the coupling assembly.

Abstract: A system for detecting a backspin condition of a motor in an electrical submersible pump is disclosed herein. The system comprises a sensor mounted proximate to the motor, the sensor outputting a signal, a power cable connected between a motor and a controller, the power cable supplying a three phase AC voltage to the motor, one phase of the three phase signal having a control signal thereon; electronics connected to the sensor, the electronics receiving the signal and propagating the signal to the controller; and a computer defining the controller, the controller having a non-transitory memory, a computer processor, and a computer program product stored on the memory and executable by the processor, the computer program product performing a process of controlling the variable speed drive of the motor and a process of monitoring the signal from the sensor to determine if the motor is backspinning.

Abstract: An electrical submersible pump assembly has a pump discharge head with an integrally formed pump discharge pressure port. The discharge head is mounted directly to the pump and couples the pump to production tubing. A static pressure port extends directly through the side wall of the discharge head. The pressure port includes a tubing connector for hydraulic tubing to run down to the gauge. Inside the discharge head, a flow limiter is located in the pressure port to stop the loss of fluid if there is a break in the tubing connector or hydraulic line. Alternatively, the discharge head may incorporate a venturi or other pressure drop structure to allow the fluid flow to be measured via a pressure drop across an orifice. The venturi may be configured as an insert to permit it to be replaced after it has become worn by abrasive flow.

Abstract: An electrical submersible pumping (ESP) system can include a pump located in a wellbore, a motor attached to the pump, a power source located at the surface, a cable electrically coupling the power source and the motor, and a current sensor. The ESP system can also include a controller communicating with the current sensor to calculate a voltage drop associated with the cable responsive to an impedance of the cable. The controller can also control a power source output voltage responsive to the calculated voltage drop. For example, the controller can adjust the power source output voltage to minimize a cable current while maintaining a minimum motor voltage. The controller can also control a motor shaft speed by changing a power source output voltage frequency to compensate for changing slip and adjust the power source output voltage to minimize the cable current while maintaining a minimum motor voltage.

Abstract: Systems and methods for controlling an electrical drive such as is used with electric submersible pumps used in downhole oil production, wherein the drive automatically determines the proper phasing to drive the pump motor in a forward direction. In one embodiment, a method includes generating a drive signal having an initial phasing and driving the pump to establish a column of fluid in the borehole. The drive signal is then discontinued, allowing the column of fluid to fall through the pump and cause the pump to backspin and generate a signal having phasing corresponding to the reverse rotational direction. The forward phasing is then determined to be the opposite of the phasing corresponding to the reverse rotational direction. The pump can be restarted in the forward direction, or an operator can be notified of the proper phasing to produce forward rotation of the pump.

Abstract: A device and method can detect, and also break, an occurrence of gas lock in an electrical submersible pump assembly in a well bore based upon surface or downhole data without the need for operator intervention. To detect an occurrence of gas lock, an instantaneous value is monitored using a sensor. Then a controller compares the instantaneous value to a threshold value over a predetermined duration to thereby detect the occurrence of gas lock in the electrical submersible pump assembly. Sensors can include, for example, a differential pressure gauge, a pressure gage located in a pump stage located toward the inlet, a fluid temperature sensor located toward the discharge, a free gas detector located near the pump discharge, an electrical resistivity gage, a flow meter located within surface production tubing, and a vibration sensor attached to a tubing string to measure a vibration signature.

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 electrical power and to downhole oil production equipment such as electrical submersible pumps, wherein the outputs of multiple power modules are individually filtered before being added together to obtain a high voltage output that is provided to the downhole equipment. In one embodiment, an electrical drive system includes multiple power modules and corresponding filters. Each of the power modules is configured to receive an input power signal and to provide a corresponding pulse width modulated or stepped intermediate signal. The signal output by each power module is individually filtered to remove at least a portion of high-frequency components in the signal. The power modules and filters are coupled together in a configuration in which the filtered signals of the power modules are added to produce an output drive signal that is used to drive equipment such as an electrical submersible pump.

Abstract: Systems and methods for reliably communicating data at high data rates between surface and downhole equipment over a power cable by multiplexing data, modulating the data onto orthogonal carrier frequencies, communicating the modulated carrier signals over the power cable, recovering of the modulated signals, and demodulating the data stream from the recovered signal. One embodiment comprises a system that includes surface equipment connected by a power cable to an ESP system that has a gauge package connected to it. The gauge package uses a high-temperature DSP to perform the data processing associated with OFDM communications.

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: A system for detecting a backspin condition of a motor in an electrical submersible pump is disclosed herein. The system comprises a sensor mounted proximate to the motor, the sensor outputting a signal, a power cable connected between a motor and a controller, the power cable supplying a three phase AC voltage to the motor, one phase of the three phase signal having a control signal thereon; electronics connected to the sensor, the electronics receiving the signal and propagating the signal to the controller; and a computer defining the controller, the controller having a non-transitory memory, a computer processor, and a computer program product stored on the memory and executable by the processor, the computer program product performing a process of controlling the variable speed drive of the motor and a process of monitoring the signal from the sensor to determine if the motor is backspinning.

Abstract: A system for determining whether a motor in an electrical submersible pump is backspinning is described herein. The system comprises a sensor mounted in a well bore proximate to a ground surface, the sensor outputting a backspin signal; a communication link connected to the sensor, the communications link communicating the backspin signal; and a controller receiving the backspin signal from the communications link and processing the backspin signal to determine whether the motor is backspinning.

Abstract: Systems and methods for controlling an electrical drive such as is used with electric submersible pumps used in downhole oil production, wherein the drive automatically determines the proper phasing to drive the pump motor in a forward direction. In one embodiment, a method includes generating a drive signal having an initial phasing and driving the pump to establish a column of fluid in the borehole. The drive signal is then discontinued, allowing the column of fluid to fall through the pump and cause the pump to backspin and generate a signal having phasing corresponding to the reverse rotational direction. The forward phasing is then determined to be the opposite of the phasing corresponding to the reverse rotational direction. The pump can be restarted in the forward direction, or an operator can be notified of the proper phasing to produce forward rotation of the pump.

Abstract: An electrical submersible pumping assembly having a seal section and a motor section, and seals that prevent leakage from the seal section and the motor section during assembly. The seals cooperate with a coupling assembly for coupling together shafts from both the seal section and motor section. The coupling assembly outer diameter enlarges at a shoulder that circumscribes its outer surface. In one example, the seal that prevents leakage from the seal assembly provides a sealing interface around the larger diameter portion of the coupling assembly, that is removable by sliding the coupling so its smaller diameter portion is adjacent the seal assembly. The motor section is sealed by another sealing assembly that includes a body that circumscribes the motor shaft to define an annulus, a sealing disk selectively fills the annulus. The sealing disk can also be slid away from within the body while coupling the shafts with the coupling assembly.

Abstract: Systems and methods for providing electrical power and to downhole oil production equipment such as electrical submersible pumps, wherein the outputs of multiple power modules are individually filtered before being added together to obtain a high voltage output that is provided to the downhole equipment. In one embodiment, an electrical drive system includes multiple power modules and corresponding filters. Each of the power modules is configured to receive an input power signal and to provide a corresponding pulse width modulated or stepped intermediate signal. The signal output by each power module is individually filtered to remove at least a portion of high-frequency components in the signal. The power modules and filters are coupled together in a configuration in which the filtered signals of the power modules are added to produce an output drive signal that is used to drive equipment such as an electrical submersible pump.

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: An electrical submersible pumping (ESP) system can include a pump located in a wellbore, a motor attached to the pump, a power source located at the surface, a cable electrically coupling the power source and the motor, and a current sensor. The ESP system can also include a controller communicating with the current sensor to calculate a voltage drop associated with the cable responsive to an impedance of the cable. The controller can also control a power source output voltage responsive to the calculated voltage drop. For example, the controller can adjust the power source output voltage to minimize a cable current while maintaining a minimum motor voltage. The controller can also control a motor shaft speed by changing a power source output voltage frequency to compensate for changing slip and adjust the power source output voltage to minimize the cable current while maintaining a minimum motor voltage.

Abstract: A device and method can detect, and also break, an occurrence of gas lock in an electrical submersible pump assembly in a well bore based upon surface or downhole data without the need for operator intervention. To detect an occurrence of gas lock, an instantaneous value is monitored using a sensor. Then a controller compares the instantaneous value to a threshold value over a predetermined duration to thereby detect the occurrence of gas lock in the electrical submersible pump assembly. Sensors can include, for example, a differential pressure gauge, a pressure gage located in a pump stage located toward the inlet, a fluid temperature sensor located toward the discharge, a free gas detector located near the pump discharge, an electrical resistivity gage, a flow meter located within surface production tubing, and a vibration sensor attached to a tubing string to measure a vibration signature.

Abstract: An electrical submersible pump assembly has a pump discharge head with an integrally formed pump discharge pressure port. The discharge head is mounted directly to the pump and couples the pump to production tubing. A static pressure port extends directly through the side wall of the discharge head. The pressure port includes a tubing connector for hydraulic tubing to run down to the guage. Inside the discharge head, a flow limiter is located in the pressure port to stop the loss of fluid if there is a break in the tubing connector or hydraulic line. Alternatively, the discharge head may incorporate a venturi or other pressure drop structure to allow the fluid flow to be measured via a pressure drop across an orifice. The venturi may be configured as an insert to permit it to be replaced after it has become worn by abrasive flow.