Abstract: A method for supplying barrier fluid in a subsea motor and pump assembly is disclosed, wherein desalinated water is extracted from or downstream of a reverse osmosis device and supplied to the motor and pump assembly, alone or as mixture with ethylene glycol. A corresponding system is likewise disclosed.

Abstract: Apparatus and method for operating a subsea compression system. The subsea compression system comprising a separator, a compressor and a pump, wherein the compressor is operable for compression and discharge of gas that is separated from a well stream fed into the separator, and the pump is operable for pumping liquid that is separated from the well stream. The compressed gas is recycled from the compressor discharge side to the compressor intake side via a turbo-expander unit which is drivingly connected to the pump, the pump operable in response to circulation of compressed gas from the compressor discharge side to the compressor intake side.

Abstract: Apparatus and method for operating a subsea compression system. The subsea compression system comprising a separator, a compressor and a pump, wherein the compressor is operable for compression and discharge of gas that is separated from a well stream fed into the separator, and the pump is operable for pumping liquid that is separated from the well stream. The compressed gas is recycled from the compressor discharge side to the compressor intake side via a turbo-expander unit which is drivingly connected to the pump, the pump operable in response to circulation of compressed gas from the compressor discharge side to the compressor intake side.

Abstract: A method of operating a subsea compression system in a well stream, the subsea compression system comprising a compressor and an electromotor driven pump, wherein the compressor is configured to compress and the pump is configured to pump liquid from the compression system. The method comprises providing a gas return line connecting a downstream side of the compressor with an upstream side of the compressor, arranging a turbo-expander unit in flow connection with the gas return line, connecting the turbo-expander unit drivingly to a generator configured to charge a battery, operating the generator in response to recycling of compressed gas through the turbo-expander unit, and operating the pump on electrical power supplied from the battery.

Abstract: The present invention describes a valve actuator having a first motor (30) for moving a valve element and a second motor (30?) for energizing a failsafe spring (130). The second motor is operated independently from the first, thus allowing the valve element to be moved between its open and closed positions while the spring is energized. In an emergency, the spring will be de-energized and move the valve element to its failsafe position no matter the position of the valve element.