Abstract: A subsea compression system and method wherein a wellstream fluid is flowed through a flow line (12) from a reservoir (10) and into a separation vessel (16) for subsequent compression in a compressor (18; 18?, 18?) prior to export of gas. A recycle line (24; 24?, 24?) is fluidly connected at a first end to the compressed wellstream at the outlet side of the compressor (18; 18?, 18?) and at a second end to the wellstream at a location between the separation vessel (16) and the inlet side of the compressor (18; 18?, 18?), the recycle line being capable of controllably (32) feeding fluid due to surge back to the compressor inlet side and avoiding the need to feed the fluid into the separation vessel, because the re-circulated gas is dry both due to having been separated at seawater temperature, and then being heated during recirculation.

Abstract: A subsea gas compressor module having a housing comprising a sealing element generally defining within the pressure housing a first compartment holding as compressor and a second compartment holding an electric motor, the compressor and motor being driveably connected by at least one shaft. The first compartment is connected to an inlet line and an outlet line for sealing hydro carbon gas and for discharging gas. The second compartment has magnetic bearings for supporting the at least one shaft, and a pressure and volume regulator is fluidly connected to the second compartment and a gas supply, and includes elements for sensing respective pressures in the inlet and outlet lines whereby, based on the magnitude of sensed pressure, the pressure and volume regulator controls the pressure at which gas is injected into the second compartment.