Systems and methods for authentication may include balancing an unbalanced power cable using a transformer that has one or more phases by selecting a voltage on a tap handle; disposing a first bushing on one or more phases at a different voltage than the selected voltage; and balancing the unbalanced power cable based on the disposition of the first bushing on the one or more phases at the different voltage.

A stator for a downhole-type motor includes a housing. The housing includes a sleeve. The sleeve includes a first layer, a second layer, and a third layer. The first layer is erosion-resistant. The second layer is corrosion-resistant. The third layer can provide structural support. The stator includes a motor stack. The stator can be used to drive a rotor disposed within an inner bore of the housing.

A system for dewatering a subsea gas pipeline includes a pig launcher at the pipeline's upper end, which may be at or near the sea surface, and a pig receiver at the pipeline's lower end, which may be at or near the sea floor. A multiphase pump unit is deployed at the pipeline lower end and is configured to provide sea water suction to aid in a pig train being forced downwards through pipeline. The multiphase pump is configured to handle some amount of gas leaking around the pig train. A choke system may allow sea water to enter the flowline, thereby lowering the gas volume fraction (GVF) and preventing the GVF from exceeding the ability of the multiphase pump. For deeper water applications, a second pump may be provided in series that may be a single pump if positioned downstream of the multiphase pump.

An electric submersible pump (ESP) assembly. The ESP assembly comprises a first ESP component having a first drive shaft defining a plurality of male splines and defining at least one cut-out area; a second ESP component having a second drive shaft defining a plurality of male splines; a coupling shell defining a first plurality of female splines configured to mate with the male splines of the first drive shaft, a second plurality of female splines configured to mate with the male splines of the second drive shafts, and at least one shouldered aperture configured to align with the cut-out area of the first drive shaft; and at least one removable lug having a pin that is configured to extend through the shouldered aperture in the coupling shell to engage with the at least one cut-out area of the first drive shaft.

A pump assembly includes multiple impeller stages, each impeller stage including at least one impeller vane. At least one impeller stage includes at least one impeller vane with at least one perforation disposed therethrough.

A subsea assembly comprising an electric subsea machine having an electric motor driving an operator, and a coolant circuit at least partially located in thermal contact with the electric motor, the coolant circuit including a cooling assembly located externally from the subsea machine, the cooling assembly comprising at least a heat transfer element, the subsea machine and the cooling assembly being supported by a common supporting frame; at least a part of the heat transfer element is integrated in the frame.

A pumping arrangement includes first and second multistage pumps. Each pump includes a housing with a pump unit, the housing includes a pump inlet and a pump outlet, the pump unit includes a plurality of impellers to convey fluid from the pump inlet to the pump outlet, and a pump shaft extending from a drive end to a non-drive end, each impeller mounted to the pump shaft. The second multistage pump includes a first mechanical seal having a process side facing the pump unit. The pump outlet of the first multistage pump connected to the pump inlet of the second multistage pump, so that the first multistage pump and the second multistage pump are arranged in series. The process side of the first mechanical seal of the second multiphase pump is in fluid communication with the pump inlet of the first multistage pump.

A technique facilitates movement of fluids with reduced component loading by utilizing opposed axial forces. The system for moving fluid may be in the form of a gas compressor, liquid pump, or other device able to pump or otherwise move fluid from one location to another. According to an embodiment, the system includes rotor sections which are combined with pumping features. The rotor sections are disposed radially between corresponding inner and outer stator sections which may be powered to cause relative rotation of inner and outer rotor sections in opposite directions. The rotors and corresponding pumping features are configured to move fluid in opposed axial directions toward an outlet section so as to balance axial forces and thus reduce component loading, e.g. thrust bearing loading.

An electric submersible pumping system includes a motor filled with motor lubricant, a pump driven by the motor, and a fluid expansion chamber connected to the motor. The fluid expansion chamber includes a seal bag filled with a seal bag lubricant and a bellows contained within the seal bag. The bellows includes an interior in fluid communication with the motor and an exterior in fluid communication with the seal bag lubricant.

A method comprises operating an electric submersible pump (ESP) motor downhole in a well. The ESP motor is electrically connected to a variable speed drive (VSD) proximate to the well. The operating comprises measuring a revolution rate and a motor current of the ESP motor for a first period of time and performing a first adjustment of a voltage output of the VSD. The method comprises measuring, after the first adjustment, the revolution rate and the motor current of the ESP motor for a second period of time determining a difference between the motor current measured for the first period of time and the motor current measured for the second period of time; and performing a second adjustment of the voltage output of the VSD based on a change in the revolution rate and the motor current between the first period of time and the second period of time.