Análise probabilística da falha por colapso de risers e dutos submarinos corroídos

Abstract

Oil and gas offshore pipelines are one of the main components of a subsea system. . In this scenario, many companies have changed their procedures to ensure the structural integrity of their pipelines - from a model that incorporates empirical safety factors and periodic inspections to another, based on methods that consider concepts of structural reliability to establish risk based inspections. In general, some rules present recommendations that may result in conservative or non-conservative analyses depending on the degree of uncertainty of the parameters affecting the considered failure mode. Stochastic analyses are recommended for a more consistent evaluation of corroded pipelines integrity. This approach provides a method to analyze the collapse of corroded submarines pipelines under external pressure. Concepts of structural reliability are applied with limit state functions to evaluate failure probability and the detrimental effect of corrosion damages on the pipelines. This reliability model consider material properties, geometric and operational parameters of pipelines, defects inspections and their uncertainties.