高温多元热流体注采液中N80钢的腐蚀行为

采用高温高压釜失重法和扫描电子显微镜(SEM)对多元热流体中N80钢的高温腐蚀行为进行了研究。结果表明,在高压CO2和有少量O2的介质中,温度40～280℃范围内,N80钢的腐蚀速率出现两个极大值,分别在60℃和180℃,这与钢表面碳酸亚铁膜和氧化膜的生成及变化有关。240℃时N80钢的静态腐蚀速率最大,动态下流速增大对腐蚀速率的影响较小,高温下动态腐蚀主要由氧传质控制,O2加速了N80钢的高温CO2腐蚀。

Corrosion Behavior of N80 Steel in High Temperature Multi-component Thermal Fluid for Thick Oil Exploitation

Corrosion behavior of N80 steel in high temperature multi-component thermal fluid was studied by weight loss method in autoclave and scanning electron microscopy.The results showed that in the medium with high pressure carbon dioxide and slight oxygen in the temperature range 40~280 ℃,there were two corrosion rate peaks of the steel at 60 ℃ and 180 ℃ respectively.The corrosion characteristics were concerned with the variation of corrosion product mainly composed of ferrous carbonate and oxide.In the multi-component thermal fluid,the static corrosion rate of the steel reached the maximum,and in dynamic state the flow rate only showed a slight effect on the corrosion rates.So the high dynamic corrosion is dependent on the oxygen mass-transfer control.Oxygen increases the CO2 corrosion of steel N80 at high temperatures obviously.