摘要
为分析盐穴地下储气库氮气阻溶条件下管柱的氧腐蚀情况,预测其服役寿命,通过室内高温高压腐蚀失重试验,研究氮气纯度对N80管材的气液两相腐蚀规律,并结合X射线荧光光谱(XRF)分析、X射线衍射(XRD)分析、扫描电镜(SEM)分析等表面分析技术对腐蚀产物进行表征分析。最后基于均匀腐蚀速率对管材的腐蚀寿命进行预测。研究结果表明:试验条件下,液相腐蚀速率随氮气纯度升高逐渐降低,氮气纯度在78%~95%范围内时,液相腐蚀严重,需考虑管材的防腐,液氮环境(氮气纯度为99.9%)中,液相腐蚀速率低于油田腐蚀控制指标0.076 mm/a,可不考虑管材的腐蚀影响。随氮气纯度的增加,内、外管在不同工况下的服役寿命均逐渐延长。99.9%、95.0%、90.0%和78.0%的氮气纯度均可满足3 a造腔周期的管柱强度;在5 a造腔周期下,建议氮气纯度下限为90.0%。该研究成果可为盐穴储气库造腔提供有力依据。
In order to analyze the oxygen corrosion of the pipe string under the nitrogen anti-soluble condition in the salt cavern underground gas storage and predict its service life,the high temperature and high pressure corrosion weight loss test was carried out in laboratory to study the gas-liquid two-phase corrosion law of nitrogen purity on N80 tubular goods;then,combined with surface analysis techniques such as X-ray fluorescence spectrum(XRF)analysis,X-ray diffraction(XRD)analysis and scanning electron microscopy(SEM)analysis,the corrosion products were characterized and analyzed;and finally,based on the uniform corrosion rate,the corrosion life of the tubular goods was predicted.The study results show that under the experimental conditions,the liquid corrosion rate decreases with the increase of nitrogen purity;when the nitrogen purity is in the range of 78%~95%,the liquid corrosion is serious,and the corrosion prevention of tubular goods needs to be considered;in the liquid nitrogen environment(nitrogen purity is 99.9%),the liquid corrosion rate is lower than the oilfield corrosion control index 0.076 mm/a,the corrosion effect of the tubular goods needs not be considered;as the nitrogen purity increases,the service life of inner and outer pipes under different working conditions increases gradually;the 99.9%,95.0%,90.0 and 78.0%nitrogen purity all can meet the pipe string strength of 3 a cavity building period;and for 5 a cavity building period,the lower limit of nitrogen purity is proposed to be 90.0%.The study results provide a strong basis for the cavity building of salt cavern underground gas storage.
作者
万里平
王柏辉
谢萌
胡成
文云飞
Wan Liping;Wang Baihui;Xie Meng;Hu Cheng;Wen Yunfei(State Key Laboratory of Oil&Gas Reservoir Geology and Exploitation,Southwestern Petroleum University;Jiangsu Underground Gas Storage Company of North China Petroleum Administration Bureau)
出处
《石油机械》
北大核心
2022年第2期137-144,共8页
China Petroleum Machinery
基金
中国石油华北油田分公司科技项目“盐穴储气库氮气阻溶井筒腐蚀模拟研究”(2020-HB-CQK1)。
关键词
盐穴地下储气库
氮气纯度
阻溶剂
氧腐蚀
管柱腐蚀
寿命预测
salt cavern underground gas storage
nitrogen purity
dissolution retardant
oxygen corrosion
pipe string corrosion
life prediction
