Internal Corrosion Direct Assessment of Gas Transmission Pipelines

Abstract An internal corrosion assessment methodology applied to gas transmission systems was developed and is termed ‘Internal Corrosion Direct Assessment’ (ICDA). The ICDA method can be used to enhance the assessment of internal corrosion in pipelines and help ensure pipeline integrity. The method is applicable for gas transmission lines that normally carry dry gas but may suffer from short term upsets of wet gas or liquid water (or other electrolyte). The basis behind ICDA is that detailed examination of locations along a pipeline where an electrolyte such as water would first accumulate provides information about the remaining length of pipe. The primary goal of the approach is to determine if internal corrosion is likely or unlikely to exist in a chosen length of pipe. If the locations along a length of pipe most likely to accumulate electrolyte have not corroded, then other locations less likely to accumulate electrolyte may be considered free from corrosion and not require further examination.