地质封存环境CO_(2)压力影响水泥碳化程度的试验研究  

Experimental Study of the Effect of CO_(2) Pressure on the Degree of Cement Carbonation Under Geologic CO_(2) Storage Environment

作　　者：刘思楠 张力为 甘满光 雷宏武[1] 方志明[1,2] 王燕 付晓娟[1] 季备[3] 姚志勇[3] LIU Sinan;ZHANG Liwei;GAN Manguang;LEI Hongwu;FANG Zhiming;WANG Yan;FU Xiaojuan;JI Bei;YAO Zhiyong(State Key Laboratory of Geomechanics and Geotechnical Engineering(Institute of Rock and Soil Mechanics,Chinese Academy of Sciences),Wuhan 430071,Hubei Province,China;University of Chinese Academy of Sciences,Shijingshan District,Beijing 100049,China;China Railway First Survey and Design Institute Group Co.,Ltd.,Xiʼan 710043,Shaanxi Province,China)

机构地区：[1]岩土力学与工程国家重点实验室(中国科学院武汉岩土力学研究所),湖北省武汉市430071 [2]中国科学院大学,北京市石景山区100049 [3]中铁第一勘察设计院集团有限公司,陕西省西安市710043

出　　处：《中国电机工程学报》2022年第9期3126-3134,共9页Proceedings of the CSEE

基　　金：国家重点研发计划项目(2019YFE0100100);铁一院重点研究项目(222018YH310912);铁一院科研项目(院科19-08)。

摘　　要：为研究封存在地下储层中的CO_(2)与井筒水泥和地下混凝土构筑物接触后引发碳化反应的剧烈程度,将普通硅酸盐水泥和G级油井水泥样品与不同浓度的CO_(2)进行反应,利用微米CT、X射线衍射仪(X-ray diffraction,XRD)等分析手段,研究水泥与CO_(2)反应后微观结构、矿物组分及含量的变化。试验结果表明,水泥的碳化速率先增大后减小;CO_(2)浓度越高,反应生成的方解石越多;方解石沉淀后形成致密壳状结构。通过Elovich方程拟合试验数据,预测得到100天后3组水泥样品的碳化深度分别为0.51 mm、2.06 mm和0.81 mm。综上所述,水泥的碳化反应主要是钙基水泥水化物转化为方解石,G级油井水泥抗CO_(2)腐蚀性优于普通硅酸盐水泥。研究成果增进了人们对水泥与高浓度CO_(2)反应机理的认识,可为相关工程的水泥服役性能评价提供参考依据。The CO_(2)stored in the underground reservoir may contact wellbores and underground concrete structures,causing carbonation reaction.To understand the severity of the carbonation reaction between CO_(2)and wellbore cement/concrete,ordinary Portland cement and class G oil well cement samples were used to react with different concentrations of CO_(2).Micro-CT and XRD were used to study the changes in microstructure and mineral compositions of the cement after the reaction with CO_(2).The test results show that the carbonation rate first increases and then decreases.The higher the CO_(2)concentration,the more the calcite can be produced by the reaction.The Elovich equation was applied to fit the test data,and the data-fitting results predict that the long-term carbonation depths of Group 1,2 and 3 samples after 100 days reaction will be 0.51 mm,2.06 mm and 0.81 mm,respectively.In summary,the carbonation reaction of cement is mainly the conversion of calcium-based cement hydrates into calcite,and Class G oil well cement has better CO_(2)corrosion resistance than ordinary Portland cement.The research results improve people’s understanding of the reaction mechanism between cement and high-concentration CO_(2),and can provide a reference for the evaluation of cement service performance in related projects.

关 键 词：二氧化碳 地质封存 水泥碳化 CT表征 微观结构 数据拟合 

分 类 号：TU52[建筑科学—建筑技术科学]