(102a) RIV and SSIV Installations On Deepwater Platforms: A Decision Making Screening Tool

Fires have been identified as major potential hazards for deepwater offshore production facilities. For facilities where the length of risers can reach thousands of feet, inventories of oil or gas within the risers can be very large. When oil or gas is accidentally released and ignited, riser fires for durations of hours might occur and pose a risk to personnel, assets, company reputation and the environment.

This paper will discuss the effectiveness of isolation valves in limiting releasable riser inventories and thereby mitigating fire hazards on deepwater offshore platforms. The approach is based on fire consequence modeling and impairment analysis due to riser fires. When riser fires are long in duration, options such as installing Riser Isolation Valves (RIV) and/or Sub-Sea Isolation Valves (SSIV) on risers can be considered. These isolation valves are intended to significantly reduce the inventory in case of a release from a riser and thus reduce the fire duration. The effectiveness of an RIV and/or SSIV depends on the fire duration and flame length.