Internal corrosion is an increasing problem world-wide in on and offshore pipelines. This paper describes how the results of genuine high resolution magnetic flux leakage (MFL) inspection together with fitness-for-purpose assessments are used as the basis for defining cost effective rehabilitation strategies for internally corroding pipelines. Strategies are highlighted for pipelines containing ‘active’ corrosion which cannot be eliminated. Attention is given to (i) advances in the methods for assessing the significance of corrosion and (ii) the benefits of using modem reliability methodologies which allow the probability of failure with time to be determined. Case studies are presented on the successful use of the above methods.
Keywords: transmission pipelines, corrosion, internal inspection, fitness-for-purpose, reliability, rehabilitation.