PR015-183601-Z01 Enhancement of Internal Corrosion Threat Guidelines for Dry Natural Gas Pipelines

This study collected and analyzed more field data to enhance the probabilistic model for predicting internal corrosion threats in nominally dry natural gas pipelines developed previously, especially in the region where the internal corrosion risk is higher. The Excel® tool developed previously was also updated with the enhanced model for predicting internal corrosion risk based on basic operating conditions, (i.e., average gas operating temperature, seasonal gas operating temperature amplitude, and operating pressure). In this project, a general-purpose Excel tool was created to allow calculation of residual hydrotest water evaporation time for one or more liquid water pools located in low spots in the pipeline based on water volume, pipe low spot geometry, and gas flow conditions. Another Excel tool also was developed to predict water stream length when gas from the inlet branch line at higher temperature injects water stream into the main gas transmission pipeline and the time to reach steady state condition before the water is completely evaporated for many types of pipeline scenarios.