In this paper, a reassessment using the NACE International Standard Practice SP0116-2016 for Multiphase Flow – Internal Corrosion Direct Assessment (MP-ICDA) protocol was conducted for the first time on three pipelines which were originally assessed in 2011 using the NACE International SP0208-2008 Liquid Petroleum ICDA (LP-ICDA) methodology. The LP-ICDA and MP-ICDA methodologies were compared in the reassessment. The paper discusses how the new data and the previous LP-ICDA 2011 data was integrated. Notwithstanding, the pipeline did not undergo any significant changes since the previous assessment approximately 8 years earlier. However, the use of the MP-ICDA protocol revealed new information regarding additional internal corrosion threats which the previous LP-ICDA protocol did not capture. This paper also details how the 2011 and the current 2019 Detailed Examinations were compared to enhance the accuracy of forecasting corrosion rates, despite using different excavation sites. New information revealed by the MP-ICDA reassessment, led to recommendations that would further reduce the possibility of general and pitting corrosion going forward and thereby potentially prolong the life of the subject pipelines.

Key words: MP-ICDA, LP-ICDA, reassessment