Abstract: Systems, methods, and apparatus, including computer programs encoded on computer-readable media, for monitoring an electromotive force (EMF) for an electrical submersible pump (ESP) having a permanent magnet motor (PMM) are disclosed. One or more voltages and one or more currents may be monitored in a cable coupled to the ESP having the PMM and being used in a well system. It may be determined whether at least one of the one or more voltages in the cable exceeds a voltage threshold and whether at least one of the one or more currents in the cable exceeds a current threshold. A notification may be generated to indicate an EMF condition if at least one of the one or more voltages and the one or more currents in the cable exceeds at least one of the one or more thresholds.

Abstract: Processing device-based systems and methods of testing IGBTs of a variable frequency drive inverter for proper functioning. The variable frequency drive may be used to control a motor, or another load associated with a hydrocarbon wellbore operation. During testing, a conductivity test can be performed on the IGBTs of the inverter, and if the conductivity test is passed, a quality check can be subsequently performed. The quality check can determine that one or more IGBTs of the inverter are not functioning properly when a discharge profile generated as part of the quality check differs from a stored reference discharge profile. The ability to assure that the IGBTs of a variable frequency drive are functioning properly can prevent potentially serious problems related to IGBT failure.

Abstract: Processing device-based systems and methods for controlling an electric motor of an electric submersible pump system in a balanced current condition using a variable speed drive despite an impedance imbalance of an electric cable connecting the electric motor to the variable speed drive. The systems and methods can utilize estimated motor shaft angular position and speed values, as well as values of three-phase motor currents measured at an output of an inverter of the variable speed drive as input information. Positive-sequence and negative-sequence current components may be extracted from measured current values and compared to reference values. The system provides an overall voltage command in the abc reference frame to a pulse width modulation controller, which generates an inverter switching pattern that will control the electric motor of the electric submersible pump system in a balanced current condition.

Abstract: Systems, methods, and apparatus, including computer programs encoded on computer-readable media, for monitoring an electromotive force (EMF) for an electrical submersible pump (ESP) having a permanent magnet motor (PMM) are disclosed. One or more voltages and one or more currents may be monitored in a cable coupled to the ESP having the PMM and being used in a well system. It may be determined whether at least one of the one or more voltages in the cable exceeds a voltage threshold and whether at least one of the one or more currents in the cable exceeds a current threshold. A notification may be generated to indicate an EMF condition if at least one of the one or more voltages and the one or more currents in the cable exceeds at least one of the one or more thresholds.

Abstract: Processing device-based systems and methods for controlling an electric motor of an electric submersible pump system in a balanced current condition using a variable speed drive despite an impedance imbalance of an electric cable connecting the electric motor to the variable speed drive. The systems and methods can utilize estimated motor shaft angular position and speed values, as well as values of three-phase motor currents measured at an output of an inverter of the variable speed drive as input information. Positive-sequence and negative-sequence current components may be extracted from measured current values and compared to reference values. The system provides an overall voltage command in the abc reference frame to a pulse width modulation controller, which generates an inverter switching pattern that will control the electric motor of the electric submersible pump system in a balanced current condition.

Abstract: Processing device-based systems and methods of testing IGBTs of a variable frequency drive inverter for proper functioning. The variable frequency drive may be used to control a motor, or another load associated with a hydrocarbon wellbore operation. During testing, a conductivity test can be performed on the IGBTs of the inverter, and if the conductivity test is passed, a quality check can be subsequently performed. The quality check can determine that one or more IGBTs of the inverter are not functioning properly when a discharge profile generated as part of the quality check differs from a stored reference discharge profile. The ability to assure that the IGBTs of a variable frequency drive are functioning properly can prevent potentially serious problems related to IGBT failure.

Abstract: Systems and methods of restarting a downhole pump for pumping downhole fluid and located in a wellbore that include determining a pump reverse rotational frequency of a downhole pump caused by downhole fluid flowing in a downhole direction using a phase locked loop. A pump motor is driven at a motor reverse rotational frequency matching the pump reverse rotational frequency. The pump motor is then driven to accelerate the pump reverse rotational frequency and thereby pump the downhole fluid in an uphole direction. The pump motor is then driven to decrease the pump reverse rotational frequency while continuing to pump the downhole fluid in the uphole direction. The pump motor is then driven to change the rotation of the downhole pump to a forward rotation at a pump forward rotational frequency to pump the downhole fluid in the uphole direction.

Abstract: Systems and methods of restarting a downhole pump for pumping downhole fluid and located in a wellbore that include determining a pump reverse rotational frequency of a downhole pump caused by downhole fluid flowing in a downhole direction using a phase locked loop. A pump motor is driven at a motor reverse rotational frequency matching the pump reverse rotational frequency. The pump motor is then driven to accelerate the pump reverse rotational frequency and thereby pump the downhole fluid in an uphole direction. The pump motor is then driven to decrease the pump reverse rotational frequency while continuing to pump the downhole fluid in the uphole direction. The pump motor is then driven to change the rotation of the downhole pump to a forward rotation at a pump forward rotational frequency to pump the downhole fluid in the uphole direction.