Methods and systems for circulating fluid within the annulus of a flexible pipe riser

Disclosed is a process and system for circulating fluid within the annulus of a flexible pipe used in a riser in an offshore hydrocarbon production facility. Fluid, such as corrosion inhibitors, can be circulated in a closed loop which includes the annulus of the riser terminating at a platform or floating vessel, a fluid storage tank located on the platform or vessel and an umbilical tube terminating at the platform or vessel and at a subsea location. Use of the system to flow the fluid through the annulus can prevent or reduce corrosion of the steel members within the annulus and increase the fatigue life of the riser.