Corrosion Assessment Methodology for an Existing Pipeline Network

Abstract Ageing of pipeline networks is of major concern to Oil & Gas operators who need to ensure safe operation, avoidance of environmental pollution, and fitness for purpose of major producing assets. In this context, corrosion control is one of the major challenges that they are faced with on existing pipeline networks. This paper describes a semi-quantitative methodology for assessing the corrosion likelihood of existing production pipelines which was developed by the Company and applied over its worldwide operations. In order to be of any real value, it has to be considered necessary that this corrosion evaluation had to: Be consistent across the entire network (even worldwide),Deal with past and present corrosive conditions seen by each pipeline,Consider the efficiency of mitigation actions,Take into account available inspection data, or deal with the non-availability of said data This methodology is apparently less formal than the use of fully quantitative mechanistic models. However, it is believed to result in a higher degree of confidence as it better covers than any tool: The wide variety of corrosion and corrosion control events,And the variability of service conditions,that any pipeline experiences over its whole life time. It also places the direct accountability of the evaluation on people in charge, not on models.