Abstract: A technique facilitates controlling barrier fluid via a mechanical pressure regulation system which may be coupled with a rotating machine at a subsea location. The mechanical pressure regulation system enables controlled supply of the barrier fluid to the rotating machine and comprises a mechanical valve mechanism. The mechanical valve mechanism automatically maintains a pressure differential between the barrier fluid and a process fluid within a desired range. According to an embodiment, the mechanical valve mechanism is mechanically actuated via pressures applied to a pilot piston so as to provide barrier fluid to the rotating machine when the pressure differential reaches a lower limit and to dump barrier fluid when the pressure differential reaches an upper limit.

Abstract: A technique facilitates controlling barrier fluid via a mechanical pressure regulation system which may be coupled with a rotating machine at a subsea location. The mechanical pressure regulation system enables controlled supply of the barrier fluid to the rotating machine and comprises a mechanical valve mechanism. The mechanical valve mechanism automatically maintains a pressure differential between the barrier fluid and a process fluid within a desired range. According to an embodiment, the mechanical valve mechanism is mechanically actuated via pressures applied to a pilot piston so as to provide barrier fluid to the rotating machine when the pressure differential reaches a lower limit and to dump barrier fluid when the pressure differential reaches an upper limit.

Abstract: The present disclosure relates to system and method used to transmit power to a remote location. More specifically, the present disclosure relates to a system and method used to independently energize control and monitoring functions of a remote installation prior to and/or during energizing its main circuit.

Abstract: Low frequency power is transmitted over long distances from a surface power supply to a subsea rotating machine, such as a pump or compressor. The low frequency power is used to rotate a motor at low speed. A liquid filled magnetic step-up gear module might be used to increase the low speed motor shaft to a higher speed output shaft that can be used to operate the rotating machine. The magnetic gear module can be configured as a fixed ratio, and the surface power supply can be configured to adjust the power frequency to change the speed of a single subsea rotating machine. In other embodiments, the magnetic gear module can provide a variable gear ratio. A fixed low frequency might be transmitted from the surface and multiple subsea loads can be operated from the same power source, each having their own variable magnetic gear module.

Abstract: In rotating machine having a vertically oriented rotating shaft, a static magnetic force is used to simulate rotor weight and create the desired bearing preload. By installing a magnet the gravity based preload on the shaft journal bearings of a horizontal machine can be simulated for a vertical shaft. This can increase rotor stability, reduce the machine's vulnerability to hydraulically induced imbalance forces and give a more smooth transition through various shaft speeds.

Abstract: Heat sinks that cool electronics are mounted within a subsea housing or vessel. Springs are used to provide pressure between the heat sinks and a vessel wall. Vessel wall deformation caused by external seawater pressure is absorbed by the springs, which maintain a pre-load force according to the spring characteristics. The mechanism also allows for rack mounting of the electronics without the need for manual access in the relatively compact vessel or housing.

Abstract: A system includes an above-surface control unit and a subsea motor drive unit. The above-surface control unit includes a variable speed motor control circuit configured to generate at least one switch control signal and a first communications circuit configured to transmit the at least one switch control signal over a communications medium. The subsea motor drive unit includes a driver circuit configured to be coupled to an electric motor and comprising at least one semiconductor switch and a second communications circuit coupled to the first communications circuit via the communications medium and configured to recover the transmitted at least one switch control signal and to apply the recovered at least one switch control signal to the driver circuit.

Abstract: A system includes an above-surface control unit and a subsea motor drive unit. The above-surface control unit includes a variable speed motor control circuit configured to generate at least one switch control signal and a first communications circuit configured to transmit the at least one switch control signal over a communications medium. The subsea motor drive unit includes a driver circuit configured to be coupled to an electric motor and comprising at least one semiconductor switch and a second communications circuit coupled to the first communications circuit via the communications medium and configured to recover the transmitted at least one switch control signal and to apply the recovered at least one switch control signal to the driver circuit.

Abstract: A technique facilitates controlling barrier fluid via a mechanical pressure regulation system which may be coupled with a rotating machine at a subsea location. The mechanical pressure regulation system enables controlled supply of the barrier fluid to the rotating machine and comprises a mechanical valve mechanism. The mechanical valve mechanism automatically maintains a pressure differential between the barrier fluid and a process fluid within a desired range. According to an embodiment, the mechanical valve mechanism is mechanically actuated via pressures applied to a pilot piston so as to provide barrier fluid to the rotating machine when the pressure differential reaches a lower limit and to dump barrier fluid when the pressure differential reaches an upper limit.

Abstract: Heat sinks that cool electronics are mounted within a subsea housing or vessel. Springs are used to provide pressure between the heat sinks and a vessel wall. Vessel wall deformation caused by external seawater pressure is absorbed by the springs, which maintain a pre-load force according to the spring characteristics. The mechanism also allows for rack mounting of the electronics without the need for manual access in the relatively compact vessel or housing.

Abstract: In rotating machine having a vertically oriented rotating shaft, a static magnetic force is used to simulate rotor weight and create the desired bearing preload. By installing a magnet the gravity based preload on the shaft journal bearings of a horizontal machine can be simulated for a vertical shaft. This can increase rotor stability, reduce the machine's vulnerability to hydraulically induced imbalance forces and give a more smooth transition through various shaft speeds.

Abstract: Low frequency power is transmitted over long distances from a surface power supply to a subsea rotating machine, such as a pump or compressor. The low frequency power is used to rotate a motor at low speed. A liquid filled magnetic step-up gear module might be used to increase the low speed motor shaft to a higher speed output shaft that can be used to operate the rotating machine. The magnetic gear module can be configured as a fixed ratio, and the surface power supply can be configured to adjust the power frequency to change the speed of a single subsea rotating machine. In other embodiments, the magnetic gear module can provide a variable gear ratio. A fixed low frequency might be transmitted from the surface and multiple subsea loads can be operated from the same power source, each having their own variable magnetic gear module.

Abstract: The present disclosure relates to system and method used to transmit power to a remote location. More specifically, the present disclosure relates to a system and method used to independently energize control and monitoring functions of a remote installation prior to and/or during energizing its main circuit.

Abstract: Heat sinks that cool electronics are mounted within a subsea housing or vessel. Springs are used to provide pressure between the heat sinks and a vessel wall. Vessel wall deformation caused by external seawater pressure is absorbed by the springs, which maintain a pre-load force according to the spring characteristics. The mechanism also allows for rack mounting of the electronics without the need for manual access in the relatively compact vessel or housing.

Abstract: To enable any measurement through the galvanic isolation of a subsea transformer, a topside system is used apply an AC voltage thereby generating a flux is the transformer core. The test is preferably done prior to any rotation in a subsea motor installed “behind” the transformer. Therefore, the voltage and frequency combination is be selected such that the torque produced is insufficient to rotate the motor. Impedance amplitude and phase are measured and then comparing the results of modeled fault scenarios. Faults such as, open circuits, short circuits, and loss of phase(s) can be detected prior to startup.

Abstract: Heat sinks that cool electronics are mounted within a subsea housing or vessel. Springs are used to provide pressure between the heat sinks and a vessel wall. Vessel wall deformation caused by external seawater pressure is absorbed by the springs, which maintain a pre-load force according to the spring characteristics. The mechanism also allows for rack mounting of the electronics without the need for manual access in the relatively compact vessel or housing.

Abstract: A seawater-based high resistance grounding device for a subsea transformer includes an insulated pipe mounted to the outside of the transformer so as to be exposed to seawater. The insulated pipe has two or more cylindrical metallic electrodes electrically connected to ground and to the neutral node of the secondary transformer windings. The volume of seawater within the pipe and between the electrodes provides one or more high resistance ground paths for protection of the transformer.

Abstract: To enable any measurement through the galvanic isolation of a subsea transformer, a topside system is used apply an AC voltage thereby generating a flux is the transformer core. The test is preferably done prior to any rotation in a subsea motor installed “behind” the transformer. Therefore, the voltage and frequency combination is be selected such that the torque produced is insufficient to rotate the motor. Impedance amplitude and phase are measured and then comparing the results of modeled fault scenarios. Faults such as, open circuits, short circuits, and loss of phase(s) can be detected prior to startup.

Abstract: A seawater-based high resistance grounding device for a subsea transformer includes an insulated pipe mounted to the outside of the transformer so as to be exposed to seawater. The insulated pipe has two or more cylindrical metallic electrodes electrically connected to ground and to the neutral node of the secondary transformer windings. The volume of seawater within the pipe and between the electrodes provides one or more high resistance ground paths for protection of the transformer.

Abstract: According to some embodiments, functionality of a conventional variable speed drive (VSD) for driving a subsea electric motor is “split” with the CPU with frequency converter control being located topside and the low-level switching hardware being located subsea with the subsea motor. The motor can be used, for driving a pumping or other fluid processing module in a subsea oil or gas field.