高含硫气田超深井油层高强度套管模拟工况下的抗腐蚀性能  

Corrosion resistance of high strength casing for ultra-deep wells in high sulfur gas field under simulated conditions

作　　者：邵理云[1] 李国平[1] 王和琴[1] 曾德智[2] 张智[2] 施太和[2] 

机构地区：[1]中国石化中原油田普光分公司,四川达州636156 [2]西南石油大学油气藏地质及开发工程国家重点实验室,成都610500

出　　处：《中国科技论文》2012年第6期473-476,481,共5页China Sciencepaper

基　　金：国家自然科学基金资助项目(51004084);高等学校博士学科点专项科研基金资助项目(20105121120002)

摘　　要：针对高含硫气田超深井油层套管的腐蚀问题,采用四点弯曲法和动态腐蚀失重法,利用自制的高温高压釜对SM-C110、TP110TS和TP110SS三种高强度套管钢在模拟工况下的腐蚀行为进行了研究。腐蚀测试结果表明:采用四点弯曲法对三种高强度套管钢在H2S分压为10.8 MPa、CO2分压为6.6 MPa、总压60 MPa和温度120℃模拟井下工况下,经720 h腐蚀后三种钢材试样均未开裂,在高温高压条件下三种钢材抗环境开裂性能良好,测得平均腐蚀速率约为0.11 mm/a;采用循环流动腐蚀方法测得三种钢材在模拟携水采气工况下的均匀腐蚀速率约为0.05 mm/a,腐蚀程度较轻;实验发现,在相同温度、相同腐蚀介质分压和相同总压条件下,不同实验方法测得的腐蚀速率差异较大。研究结果表明,模拟工况下高强度套管抗开裂性能良好,抗电化学失重腐蚀性能一般,油气开采过程中需对油层套管采取有效的腐蚀防护措施。Aiming at casing corrosion in ultra-deep wells of gas field with high sulfur content, we studied corrosion behavior of three high strength casing steels （SM-Cll0, TPl10TS and TPI10SS） under simulated working conditions by using four-point bending method mad dynamic weight loss method in a self-made autoclave. The results showed that the four-point bended specimens of the three steels did not crack after the 720 h corrosion test with an H2S partial pressure of 10.8 MPa, a CO2 partial pressure of 6.6 MPa, a total pressure of 60 MPa and a temperature of 120 ℃. The measured average corrosion rate was 0.11 mm/a. These suggest that the high strength casing steels exhibited excellent environmental cracking （EC） resistance at high temperature and high pressures. The circulation flow corrosion test showed that the average corrosion rate of the three steels was 0.05 mm/a in simulated conditions and the degree of corrosion of the three steels was low. There is a marked difference in the corrosion rate determined by the four-point bending method and the dynamic weight loss method under the same experimental conditions. The results show that high strength casing has good resistance to cracking but general resistance to electrochemical corrosion. Therefore, it was very important to take effective anticorrosion measures for production casing during the exploitation ofoil and gas fields.

关 键 词：高含硫气田 套管 应力腐蚀 失重腐蚀 

分 类 号：TE980[石油与天然气工程—石油机械设备]