注空气驱油过程中N80钢的腐蚀规律研究

Corrosion Rule of N80 Carbon Steel during Air Injection Enhanced Oil Recovery

目的 探明空气驱工艺条件下套管钢的腐蚀规律,为空气驱工况条件下套管钢的腐蚀防护提供数据支撑。方法 采用高温高压失重挂片法评价N80碳钢的腐蚀速度,利用扫描电镜、能谱分析等手段考察金属表面腐蚀产物膜的形态与组成,研究氧分压、温度以及腐蚀时间对注空气驱油过程中N80钢的腐蚀影响。结果 随着氧分压的增加,N80钢的腐蚀速率总体上增大。随着温度的升高,N80钢的腐蚀速率明显增大,温度为100℃时,腐蚀速度达到13.65mm/a。随腐蚀时间的延长,N80钢的腐蚀速率呈现先增大、后减小的规律,且24 h时的腐蚀速率最大,为17.41 mm/a。结论 空气驱工艺条件下,N80钢遭受严重的腐蚀,腐蚀产物主要为铁的氧化物。

This study was carried out to investigate the corrosion rule of carbon steel during air injection Enhanced Oil Recovery(EOR) process and provide data support for the corrosion protection of carbon steel under the condition of air injection EOR. Corrosion rate of N80 carbon steel was evaluated by weight-loss coupon method under high temperature and high pressure. The morphology and composition of corrosion product film on metal surface were investigated by means of SEM, EDS.The effects of oxygen partial pressure, temperature and corrosion time on the corrosion of N80 carbon steel during air injection EOR. The results indicated that the corrosion rate of N80 carbon steel generally increased along with increasing the oxygen partial pressure. With the increase of temperature, the corrosion rate of N80 carbon steel increases obviously. When the temperature is 100 ℃, the corrosion rate reaches 13.65 mm/a;With the extension of corrosion time, the corrosion rate of N80 carbon steel increases first and then decreases, and the corrosion rate is the highest at 24 h, which is 17.41 mm/a. N80 carbon steel suffered severe corrosion during air injection EOR process and the corrosion products were mainly iron oxide.