阻垢剂和CO_(2)对J55钢在油田模拟采出水中腐蚀行为的影响

Effect of Scale Inhibitor and CO_(2)on Corrosion Behavior of J55 Steel in Oil Field Simulated Produced Water

通过浸泡腐蚀和电化学腐蚀测试,研究了J55钢在不含阻垢剂和CO_(2)、只含CO_(2)、只含阻垢剂和同时含阻垢剂和CO_(2)条件下的油田模拟采出水中的均匀腐蚀和点腐蚀行为。结果表明:在不含阻垢剂和CO_(2)条件下,J55钢的均匀腐蚀速率较低,最大点蚀速率最高;相较于不含阻垢剂和CO_(2)条件,只含CO_(2)条件下该钢的均匀腐蚀速率升高,但最大点蚀速率降低,只含阻垢剂条件下该钢的均匀腐蚀速率和最大点蚀速率均降低;在同时含CO_(2)和阻垢剂条件下,该钢的均匀腐蚀速率最高,最大点蚀速率较不含阻垢剂和CO_(2)条件有所降低。当体系中存在CO_(2)时,该钢表面主要生成CaCO3或CaMg(CO3)2结垢物。同时含CO_(2)和阻垢剂条件下,阻垢剂能抑制结垢过程,改变腐蚀产物膜和结垢物的结构,失去对基体的保护作用。

The uniform corrosion and pitting corrosion behavior of J55 steel was studied in oil field simulated produced water without scale inhibitor and CO_(2),with CO_(2),with scale inhibitor and with both scale inhibitor and CO_(2)through immersion corrosion and electrochemical corrosion tests.The results show that under the condition without scale inhibitor and CO_(2),the uniform corrosion rate of J55 steel was relatively low,and the maximum pitting corrosion rate was the highest.Compared to those without scale inhibitor and CO_(2),the uniform corrosion rate of the steel increased and the maximum pitting corrosion rate decreased under the condition with CO_(2),and both decreased under the condition with scale inhibitor.Under the condition with both CO_(2)and scale inhibitor,the uniform corrosion rate of the steel was the highest,and the maximum pitting corrosion rate was lower than that without scale inhibitor and CO_(2).When CO_(2)was present in the system,CaCO3 or CaMg(CO3)2 scaling products were mainly formed on the surface of the steel.Under the condition with both CO_(2)and scale inhibitor,scale inhibitor would inhibit the scaling process,change the structure of corrosion products and scale deposits,and lost the protective effect on the matrix.