Risk Based Inspection (RBI) for Subsea Equipments

The fleet of subsea systems, such as pipelines, trees and manifolds etc is at present rapidly increasing. This paper presents a risk based inspection planning approach that is new for subsea equipments. Very few publications on RBI of subsea equipments exist and have been actually applied due to the complexity of subsea components. In this paper, failure modes are described, offshore reliability database is used and risk analysis is performed taking into account the consequences of failure of equipments mainly in terms of Asset (Loss of production, Unavailability, Costs of repair). Risk level and corresponding inspection effort are estimated. An overall inspection plan is then provided for all structural components of subsea equipments: pipelines, trees and manifolds. Such a methodology has the benefit to rank the components and results in optimization of the inspection and maintenance effort.