Structural integrity assessment of an offshore platform using RB-FEA

The wind energy is considered as one of feasible renewable energy sources especially in the offshore field to speed up the green transition. However, the cost related to the design and the installation on a new structure its structural management still slowing down the development of the wind industry in this field. The purpose of this paper is to provide a suitable solution to reduce the commissioning expenses and an innovative methodology to improve the Structural Health Management of the asset with the purpose of steam unplanned maintenance operations driving the asset towards a proactive maintenance approach that focuses on minimizing the downtime and costs associated with breakdowns and repairs. This work analyzes the structural integrity of an existing Oil \& Gas jacket platform located in the Adriatic Sea, the decommissioning and the re-utilization as wind turbine support structure. The project consists in two main phases. In the first phase, the existing structure is examined via structural analysis using a RB-FEA software. Further, the fatigue analysis is performed in order to assess the resistance of the structure with respect to the long term environmental loads during the expected working life as Oil \& Gas platform. In the second phase, the top side is decommissioned and replaced by a wind turbine using the jacket as supporting structure. Similarly to the first phase, the resistance of the jacket is assessed through the structural and the fatigue analyses. The results achieved show that the jacket is cable to withstand the loads produced by the installation of the wind turbine despite the needed of perform some maintenance operation necessary to strengthening the most stressed area of the jacket and the additional benefits that the installation of a monitoring system based on the RB-FEA, providing a data driven real time structural simulation, would have to the service life of the asset.