The industry currently has multiple models to calculate corrosion growth between several ILI results. There is also little guidance around selecting a model for young pipelines with only one ILI run. Often, operators are tasked with the decision to select more conservative models that can result in an overestimation of digs or less conservative models which can result in high leak risks.

This research looks at the results of six different models using field-found data to determine the accuracy of the predicted depths. Also, we consider the applicability of growth models in young pipelines and in negative growth cases, and where the results land on the risk vs conservatism spectrum. Our analysis can help operators understand which growth models can be used to make better decisions in specific contexts. For example, short-term dig planning must be based on the instantaneous corrosion depth and growth rate, determined by the latest one or two depth measurements, but long-term pipe replacement planning may rely on a growth rate trend over several measurements