X65钢海底管道在CO2/H2S腐蚀环境下的适用性

利用高温高压反应釜模拟试验和电化学测试,研究了X65钢海底管道在CO2/H2S环境下的耐蚀性。结果表明,不加缓蚀剂条件下,X65钢在总压为0.25MPa时的平均腐蚀速率及局部腐蚀风险与总压为0.7MPa时相比,均显著降低。添加100mg/L的缓蚀剂,X65钢的腐蚀速率显著降低,缓蚀效果较好;电化学测试与模拟试验结果一致。降压至0.25MPa分离出部分腐蚀性气体后再输送可大大降低内腐蚀风险,结合缓蚀剂措施,该腐蚀环境下可选择X65钢海底管道输送油气。

Applicability of X65 Steel Subsea Pipeline in CO2/H2S Corrosion Environments

The corrosion resistance of X65 steel subsea pipeline in CO2/H2S corrosion environments was studied by the high-pressure high-temperature autoclave and electrochemical test.The results showed that under the condition without corrosion inhibitor.the corrosion rate and localized corrosion risk of X65 steel under the 0.25 MPa total pressure condition were lower than under the 0.7 MPa total pressure condition obviously.The corrosion rate of X65 steel reduced observably when 100 mg/L corrosion inhibitor was added,showing excellent inhibition efficiency.The result of electrochemical test agreed with the simulated corrosion test.The corrosion risk of X65 steel was decreased by reducing the total pressure to 0.25 MPa,separatting a part of corrosion gas,so X65 steel can be used as subsea pipeline in oil and gas transportation in the corrosion environment with corrosion inhibitor addition.