模拟油田CO_2/H_2S环境15Cr油管腐蚀行为研究  

Corrosion Behavior of Tubing Steel 15Cr in Artificial Formation Water Solutions Containing CO_2/H_2S

作　　者：赵雪会[1,2] 冯耀荣[1,2] 尹成先 韩燕 

机构地区：[1]石油管工程技术研究院石油管工程重点实验室,西安710077 [2]西安交通大学金属材料强度国家重点实验室,西安710049

出　　处：《腐蚀科学与防护技术》2016年第4期325-331,共7页Corrosion Science and Protection Technology

基　　金：国家支撑计划项目(2015BAE03B00);中国石油集团公司技术开发项目(2014A-4214)资助

摘　　要：利用电化学动电位测试技术和高温高压失重法研究了15Cr合金油管在CO_2以及与H_2S共存环境下的腐蚀行为和变化趋势,分析了H_2S与CO_2不同时间间隔共存后对材料腐蚀性能的影响。结果表明:在实验溶液中先加入CO_2,当腐蚀电位稳定后再加入H_2S腐蚀介质时,材料阳极钝化区不稳定;当先加入CO_2且时间间隔10 min后加入H_2S介质时,材料阳极钝化区域呈现相对较稳定的状态,维钝电流密度相对减小。材料在应力状态下的腐蚀电位相对非应力状态明显下降,并且腐蚀电流密度右移,耐蚀性相对下降。高温高压实验结果表明,应力的存在促进了腐蚀程度的加剧,平均腐蚀速率明显增大。材料在加载80%σs应力且当H_2S浓度达1 MPa时,试样表面出现明显的点蚀坑,试样发生应力腐蚀断裂。Corrosion behavior of tubing steel 15 Cr was studied in artificial formation waters containing CO2 and H2S by electrochemical test technique and weight loss method. The results show that after the open circuit potential of the anode in a solution saturated with CO2 reached a stable level, the addition of H2S could induce the anode passivation region to be apparent unstable; however in a solution, to which H2S was added in 10 min after the solution was saturated with CO2, the anode presented a relatively stable passivation region with less passivation current density in the contrast to the above case. With different applied tensile stresses the corrosion potential of the steel shifted relatively negative with increasing corrosion current density in comparison with those without stress. The high temperature corrosion tests showed clearly that the stress promoted the corrosion reaction;by a condition with PH2S of 1 MPa and applied stress of 80%σs, the steel would clearly suffered from stress corrosion cracking and correspondingly, apparent pitting corrosion was observed in the stress concentration zone on the specimen surface.

关 键 词：油管 应力腐蚀 高温腐蚀 钝化 点蚀 

分 类 号：TG172[金属学及工艺—金属表面处理]