塔河油田集输管线20#钢在CO2/H2S环境中的腐蚀行为

为充分了解20#钢在塔河油田集输管线工况环境中的腐蚀行为,采用高温高压釜研究CO2/H2S分压比、温度和pH值对20#钢在CO2/H2S环境中的腐蚀规律的影响,并利用扫描电镜(SEM)分析腐蚀产物形貌特征。结果表明:CO2分压不变时,随着H2S分压的增加,20#钢的腐蚀速率先增大后减小,H2S分压为0.01 MPa时的腐蚀速率达到最大0.435 mm/a;随着温度的升高,20#钢的腐蚀速率逐渐增大,在100℃时腐蚀速率高达2.280 mm/a;CO2控制下20#钢的腐蚀速率随着pH值的增大而减小;H2S控制下20#钢的腐蚀速率随着pH值的增大而增大。

The Corrosion Behavior of 20# Steel in Tahe Oilfield Gathering and Transportation Pipeline CO2/H2S Environment

In order to fully understand the corrosion behavior of 20#steel in the gathering and transportation pipeline environment of Tahe oilfield,a high-temperature and high-pressure autoclave was used to study the influence of partial pressure ratio of CO 2/H 2S,temperature and pH value on the corrosion law of 20#steel in the environment of CO 2/H 2S,and scanning electron microscope(SEM)was used to analyze the appearance characteristics of the corrosion products.The results show that,when the partial pressure of CO 2 remains unchanged,with the increase of H 2S partial pressure,the corrosion rate of 20#steel first increases and then decreases.When the partial pressure of H 2S is 0.01 MPa,the corrosion rate reaches the maximum of 0.435 mm/a.With the increase of temperature,the corrosion rate of 20#steel increases gradually,up to 2.280 mm/a at 100℃.Under the control of CO 2,the corrosion rate of 20#steel decreases with the increase of pH value.Under the control of H 2S,the corrosion rate of 20#steel increases with the increase of pH value.