Risk-Based Approaches for Planning the Inspections of Large-Scale Topside Structural Systems

Faridafshin, Farzad (Aker Solutions) | Anvari, Majid (Aker Solutions) | Hellevig, Nils Christian (Aker Solutions)


Life-cycle safety and integrity management of offshore structures is a critical activity owing to the adverse consequences of structural failure, ranging from loss of life and financial consequences to environmental pollution. Historically, integrity management of substructures such as jacket structures has been the subject of more detailed investigations than the integrity management of topside structures. For instance, more specific risk-and reliability-based methodologies exist for integrity assurance and planning the inspections of jacket structures than for topside structures. This article presents a practical methodology for risk-based inspection planning of large-scale topside structural systems under different limit states (ultimate, accidental, fatigue, and serviceability) and degradation mechanisms (e.g., corrosion and fatigue crack growth), with a view to data analytics and digitalization. The main advantage of the presented methodology is in its capability in systematically ranking the different structural elements/areas relative to one another based on their assessed level of risk of failure, i.e. a risk-based differentiation, and planning the inspections and repairs accordingly for large-scale structural systems. Such an integrated approach will result in efficient and economical management of offshore topside structural assets and can be used as a consistent and coherent basis for lifetime extension or decommissioning of offshore platforms. Integrity management of offshore structures is known to involve the analysis and management of large amounts of data and information over the lifetime of the structure. Therefore, insights are provided in the article regarding how the presented risk-based methodologies can be integrated into a digitalized and datadriven interface--a topic currently under heated investigation across the petroleum industry, facilitating the analysis and management of the involved data and information in an efficient and verifiable manner.