SUBSEA PUMP SYSTEM WITH PROCESS LUBRICATED BEARINGS

The invention provides a subsea pump system, comprising a subsea centrifugal pump with a motor compartment and a process compartment, wherein the motor compartment is separate from the process compartment and comprises an electric motor or stator driving a motor shaft, wherein the process compartment comprises a pump arranged on a pump rotor, an inlet for fluid and an outlet for pressure boosted fluid, and wherein the motor shaft via a coupling preferably drives the pump rotor. The subsea pump system is distinguished in that it further comprises a liquid phase separator arranged downstream to the pump or downstream to at least one pump impeller, the liquid phase separator comprising: an inlet receiving the pressure boosted fluid, an outlet delivering a majority, or a minor part, of the pressure boosted fluid, and a liquid phase outlet, a liquid recirculation line, a flow mixer arranged on the inlet side of the pump, wherein the liquid recirculation line is arranged from the liquid phase outlet to the flow mixer, and a liquid lubricant line arranged from a location containing pressure boosted fluid to one or more process compartment bearings, directly or via other equipment, for lubricating said process compartment bearings.