沿井筒CO₂腐蚀规律研究

Study on CO₂ Corrosion Law along the Wellbore

摘要: 通过建立注CO₂井筒的流动传热模型，计算了井筒温度、压力分布，并通过试验研究不同井深参数下的井筒腐蚀，得出沿井筒CO₂腐蚀规律。研究结果表明，腐蚀产物膜对钢材有保护作用，N80钢的腐蚀速率沿井筒深度方向呈逐渐减小趋势；CO₂腐蚀易发生在基体表面不平整处，清除产物后基体出现裂纹和细小坑点，腐蚀产物成分主要为FeCO₃等复盐。

Abstract: A heat transfer model for CO₂ injection wellbore was established to calculate temperature and pressure distribution and study the wellbore corrosion in different depths and the law CO₂ corrosion along wellbore was obtained. The result shows that the corrosion product film plays a protective role on steel, the N80 steel corrosion rate decreases gradually along with the wellbore depth. CO₂ corrosion is easy to occur in the uneven surface of steel and cracks and small pits appear in matrix after removal of the product, the main components of corrosion products are FeCO₃, etc.