Proceedings of COMADEM 2007 The 20 th International Congress on Condition Monitoring and Diagnostic Engineering Management Faro, Portugal, June 13-15, 2007 477 PHILOSOPHICAL ASPECTS OF MODELING CORROSION OF OIL AND GAS PIPELINES Maneesh Singh 1,2 , Tore Markeset 1 and Uday Kumar 3 1 Centre for Maintenance and Asset Management, University of Stavanger, 4036, Stavanger, Norway 2 AGR EmiTeam, P.O. Box 1137, 4391, Sandnes, Norway 3 Luleå University of Technology, 97187, Luleå, Sweden ABSTRACT For the efficient design, installation, operation and maintenance of a plant, a reliable and robust mathematical model for predicting corrosion in pipelines can be a valuable asset. Such a model can help a plant supervisor to cut down on the expenditure arising from frequent inspections and unnecessary maintenance shutdowns and to take preventive maintenance action before an accident actually takes place. This paper discusses some of the philosophical issues related to the development of such a model. It also brings to fore the limitations and values of such a model. KEYWORDS Corrosion, modeling, oil and gas, philosophy, pipelines 1 INTRODUCTION The transportation of oil and gas using pipelines is very common because it is often the cheapest way among the different possible options. On the negative side, oil and gas transporting pipelines can face leakages, bursts and ruptures that can be hazardous to the workers, cause environmental damage and result in financial losses due to repairs, clean-up operations, reduced production, etc. To mitigate the problems associated with leakages, the pipelines are subjected to regular inspections. Since the pipelines are often located underground or underwater, the costs associated with their inspection and maintenance itself becomes quite high. Hence, many plants resort to risk-based integrity management strategy for planning inspection and maintenance of the pipelines. While determining the probability of failure, one needs to consider various causes of failure and their consequences. One of the common causes of failure is the severe damage to pipelines caused by the internal corrosion which can take place due to a number of factors like the presence of CO 2 , humidity, H 2 S, microbes, chlorides and sulphates. Unfortunately, the complex nature of the corrosion process makes it unamenable to modeling. From an extensive comparative study of different models carried out at the Institute of Energy Technology (IFE) under a joint industry project and using the data provided by participating oil companies, it has been concluded that different models give different predictions for the same field case and no particular model outperforms others under all conditions. Hence, the investigators