摘要
【研究目的】西宁地区中低温地热资源丰富,但地热水矿化度高、腐蚀性强,限制了地热能的高效开发,提出安全经济有效的综合井筒防腐措施,是有效利用高矿化度地热资源的基础和关键。【研究方法】本文针对西宁地区典型地热水样进行采集化验,采用高温高压反应釜,开展了金属挂片腐蚀实验,评价了在开放环境中回灌井筒条件下的钢材腐蚀风险,判断了腐蚀类型,分析了腐蚀规律及其影响因素,最后提出地热水回灌防腐建议。【研究结果】西宁盆地地热水具有较强腐蚀性,主要腐蚀成分为溶解氧、Cl^(-)、SO_(4)^(2-)、H^(+)等,可对碳钢造成均匀腐蚀、台状腐蚀及少量点蚀,主要腐蚀产物为Fe O(OH)及Fe_(3)O_(4);沿回灌井筒向下碳钢腐蚀速率先增大后减小,腐蚀规律与地热水性质、温压场、水流速及混入井筒的溶解氧等都有关系。【结论】通过拟合碳钢腐蚀实验数据,建立经验方程,利用该经验方程得到的预测值与实验值一致性较好。可从防腐管材选择、回灌水预处理、回灌工艺参数优化等角度,采取安全经济有效的综合井筒防腐措施。
This paper is the result of geothermal survey engineering.[Objective]Xining area is rich in medium and low temperature geothermal resources,but the high salinity and strong corrosion of geothermal water limit the efficient development of geothermal energy.The proposed safe,economic and effective comprehensive well bucket anticorrosion measures are the basis and key to the effective utilization of high salinity geothermal resources.[Methods]In this study,the typical geothermal water in Xining area was collected,and the ionic composition and content of corrosive bacteria were tested.The high-temperature and high-pressure reactor was used to carry out metal plate corrosion tests to evaluate the corrosion performance of geothermal water on different steels under typical wellbore conditions.The corrosion type and the relationship between the corrosion rate and the influencing factors was analyzed.Finally,the anti-corrosion measures for geothermal water reinjection were proposed.[Results]The main corrosion components in geothermal water are Cl^(-),SO_(4)^(2-),H^(+)and dissolved oxygen,which cause uniform corrosion,platform corrosion and a small amount of pitting corrosion.The main corrosion products are FeO(OH)and Fe_(3)O_(4);the corrosion rate along the wellbore gradually increases,and the corrosion risk at bottom hole is the greatest.In addition,the corrosion rate has a greater correlation with the geothermal water properties,P-T condition,flow speed and dissolved oxygen mixed into wellbore.[Conclusions]By fitting carbon steel corrosion experiment data,an empirical equation is established.The predicted value obtained by using the empirical equation is in good agreement with the experimental value.Safe,cost-effective and comprehensive wellbore anti-corrosion measures can be taken from the perspective of anti-corrosion pipes,reinjection geothermal water pretreatment,reinjection process parameters.
作者
赵振
秦光雄
耿松鹤
陈惠娟
晁嘉豪
张亮
ZHAO Zhen;QIN Guangxiong;GENG Songhe;CHEN Huijuan;CHAO Jiahao;ZHANG Liang(School of Engineering,China University of Geosciences,Wuhan 430074,Hubei,China;Qinghai Bureau of Environmental Geological Exploration,Xining 810001,Qinghai,China;Qinghai Provincial Key Laboratory of Environmental Geology,Xining 810001,Qinghai,China;Qinghai 906 Engineering Survey and Design Institute Co.,Ltd.,Xining 810001,Qinghai,China;School of Petroleum Engineering,China University of Petroleum(East China),Qingdao 266580,Shandong,China;Key Laboratory of Unconventional Oil&Gas Development,Ministry of Education,China University of Petroleum(East China),Qingdao 266580,Shandong,China)
出处
《中国地质》
CSCD
北大核心
2023年第6期1678-1690,共13页
Geology in China
基金
青海省应用基础研究计划项目(2020-ZJ-758)资助。
关键词
地热水回灌
挂片实验
腐蚀速率
氧气腐蚀
防腐措施
地热调查工程
geothermal water reinjection
metal plate test
corrosion rate
oxygen corrosion
anticorrosive measures
geothermal survey engineering
