Dry gas (DG) internal corrosion direct assessment (ICDA) methodology—NACE Standard Practice (SP) 0206-2006—was applied to a dry gas pipeline segment from Changle to Pengxi in Sichuan Province China to assess the internal corrosion (IC) threat to this pipe segment. This pipe segment was put into operation in 1987 by PetroChina. Critical angle and pipe inclination angles were calculated following the standard. In the first 3000 meters of the pipeline locations where inclination angles greater than the critical angle were chosen for excavation. Direct examinations were performed at several locations and the wall loss at the locations examined was less than 3.5% of the wall thickness. However smart pigging performed on this pipe segment in 2005 indicated significant wall loss spreading along the inner pipe surface. Such wall loss appeared at far downstream locations and on the straight pipe locations suggesting that this pipe likely suffered significant corrosion earlier in life assuming that current operation has been well controlled with low water content in gas that has not caused significant corrosion. Historical data (e.g. water content at times of gas quality upsets) are not available from the operator. Lacking historical data to understand whether frequent gas quality upsets occurred in the past causes uncertainty in applying NACE SP 0206-2006 to effectively assess this dry gas pipeline segment. This paper summarizes the assessment of internal corrosion using NACE standard and this noted uncertainty.AcknowledgmentsThe authors acknowledge technical communications and data collections of Dunjun Wang and Shuzhu Zhang of Chengdu Ludi Technology and Development Co. Ltd. Without their support this work would not have been possible.