Optimal design-phase inspection and replacement planning of pipelines subjected to CO2 corrosion

A methodology for cost optimal reliability-based inspection and replacement planning of pipelines in the design-phase is described. The degradation me chanism considered is CO2 corrosion. The methodology is based on the applic ation of methods for structural reliability analysis within the framework o f Bayesian decision theory. The planning problem is formulated as an optimi zation problem minimizing the expected lifetime costs with the minimum acce ptable reliability level as a constraint. The optimization parameters are t he nominal design wall thickness, the number of inspections in the expected lifetime. the time intervals between inspections and the inspection method to be used.