Abstract: In response to the issue of corrosion-induced perforation failure occurring in a subsea oilfield pipeline after only 3 years of service, the failure causes were determined by analyzing the pipeline material, composition of the transported medium, microbial content, as well as environmental parameters such as temperature, pressure, and flow rate. The analysis was combined with the macro- and micro-morphology of the failed pipe section and the composition of corrosion products. The results indicate that CO₂ corrosion was the primary cause of the pipeline failure, and the presence of chloride ions further exacerbated localized corrosion, ultimately leading to pipeline perforation. The findings provide a theoretical basis for analyzing corrosion failures in similar pipelines and offer targeted recommendations for preventing such failures.