Corrosion prediction in medium pressure vent pipes at high sulfur field stations through numerical analysis of internal wall liquid phase distribution.

In actual production activities, the venting pipeline systems in high-sulfur natural gas processing plants are often affected by internal corrosion, leading to reduced service life. To determine the optimal corrosion monitoring points within the venting pipelines and provide effective guidance for blowdown operation management, this study conducted a comprehensive predictive analysis of internal corrosion phenomena in the venting pipeline systems of high-sulfur natural gas processing plants. Computational Fluid Dynamics (CFD) is utilized to analyze corrosion at different cross-sections within the medium-pressure venting pipeline, considering the effects of flow field distribution, liquid phase distribution, and hydrogen sulfide distribution. Through comparison of numerical analysis results and measured data from high-sulfur natural gas field stations, the suggested analysis method is validated to be reliable and accurate. The results indicate that the distribution of the liquid phase plays a pivotal role in causing internal corrosion within the venting pipeline of high-sulfur natural gas stations. The areas most severely affected by corrosion are identified as follows: at the blind end of pipeline tees (specifically at 3, 6, and 9 o'clock positions), near the blind end at 6 o'clock, at the air inlet (positions 3, 9, and 12 o'clock), at the air outlet (position 6 o'clock), and at elbows (positions 3, 6, and 9 o'clock). The results of this study effectively contribute to predicting the locations of internal corrosion within the venting pipeline of high-sulfur natural gas field stations and providing corresponding maintenance strategies.