Ultimate bending capacity of aged fixed platform by considering the effect of marine fouling

Abstract

For offshore structures, especially jacket supported structure such as fixed platform and offshore wind turbine, the underwater area provides an ideal site for corrosion formation and marine fouling. In this marine environment, the structures are exposed to particularly aggressive corrosion and colonized by marine organisms involving a diversity of species. In this paper, a number of cases are conducted where an existing fixed platform is subjected to uniform corrosion. Furthermore, the platform is also subjected to marine fouling. The platform is assessed to investigate the effects of corrosion and marine fouling on its structural strength by determining the Reserve Strength Ratio (RSR) value. It is found the platform is limited to at least 50 years of service life when subjected to average corrosion. However, the platform is no longer considered as safe after 37 years when subjected to severe corrosion. Moreover, there is an RSR loss of 38% when marine fouling is introduced at the first 5 years which is detrimental to the overall safety of the platform. On the other hand, there is minimum RSR loss of only 5% for most cases when marine fouling is introduced but still detrimental to the overall safety of the platform. The obtained outcomes were documented and will be useful information to conduct condition assessment (or structural health monitoring) of aged fixed jacket structures.

Condition Assessment Techniques for Aged Fixed-Type Offshore Platforms Considering Decommissioning: a Historical Review

“…From then onwards, many researchers, i.e. Tromans and van de Graaf (1994), Visser (1995), Sturm et al (1997), Bea (2000), Hansen and Gudmestad (2001), Capanoglu and Coombs (2009), Bao et al (2009), Gening and Ruiguang (2010), Håbrekke et al (2011), Solland et al (2011), Ayob et al (2014b), Kurian et al (2014a, b), George et al (2016), Kim et al (2017b) and Mohd Hairil et al (2019), have utilised the reassessment guideline from the standards to demonstrate the safety of platforms by considering ageing effects as well as the low-risk potential for environmental damage from the operation of those platforms. A study related to the decommisioned offshore platforms converted in offshore wind turbine is also recently introduced by Alessi et al (2019).…”

Urushiol-Based Benzoxazine Containing Sulfobetaine Groups for Sustainable Marine Antifouling Applications

“…Marine biofouling refers to the adherence of marine organisms on the surfaces of marine equipment, leading to economic damage in terms of human marine activities [ 1 , 2 ]. Marine biofouling is a global issue with permanent detrimental consequences on machinery [ 3 , 4 ]. Currently, petroleum-based resin self-polishing antifouling coatings comprising cuprous oxide (Cu 2 O) and a powerful biocide (such as zinc thiopyridine, copper/zinc pyridine thione, etc.)…”