Optimal Inspection Methodology for Offshore Structures Based on an Economic Decision Theory

About 200 marine platforms are installed in the Mexican sector of the Gulf of Mexico so that maintenance and inspection schedules play an important role to avoid excessive structural deterioration of the oil facilities and at the same time to keep the facilities within acceptable safety margins. Large costs associated with inspection and repair actions moved managers towards the application of an optimal strategy in order to minimize inspection expenses. For these purposes, it is necessary to consider deterioration process such as fatigue crack growth under the influence of uncertain wave loading which is the dominant force while effort is focused on maintaining structural integrity and safe production. This paper presents an optimal inspection methodology for offshore structures based on an economic decision theory, bearing in mind that large costs are associated with structural failure and extensive inspection and repairs. A system failure analysis of a given sub set of the critical structural components is included as well as a mathematical framework for the assessment of failure and repair cost associated.