CCUS环境下温度影响G级油井水泥碳化过程的试验研究  

Experimental study on effect of temperature on carbonization process of G-class oil well cement under CCUS environment

作　　者：龙丹 曾雪玲 赵峰 张洋勇 张凌志 魏雪琦 王佳 LONG Dan(Jiahua Special Cement Co.LTD.,Leshan 614003,Sichuan,China)

机构地区：[1]嘉华特种水泥股份有限公司,四川乐山614003

出　　处：《水泥》2024年第12期1-4,共4页Cement

基　　金：中国建材集团攻关专项(2021HX0708)。

摘　　要：CCUS技术作为一项控制温室效应、实现人类社会可持续发展的重要新兴技术,逐渐受到国际社会的广泛关注。然而在CO_(2)注入和长期封存过程中,固井水泥长期与CO_(2)接触会存在CO_(2)腐蚀问题,导致固井水泥石的结构完整性被破坏。为了探究富含CO_(2)的井下环境中,G级油井水泥在不同温度下的碳化腐蚀过程,本文利用XRD、TG/DTG、FTIR及SEM等微观测试进行分析。结果表明:不同温度下水泥石碳化后均形成大量的方解石和文石,且方解石占据主导地位。随着碳化温度和龄期的增加,水泥石C-S-H凝胶和CH均参与碳化反应,试样中方解石和文石的含量逐渐升高,碳化程度加深。随着碳化温度和龄期的增加,C-S-H凝胶和CH逐渐转变为CaCO_(3)晶体,导致体积变化;而CaCO_(3)晶体逐渐发育长大,导致水泥石基体内部发生膨胀,形成大量裂纹和孔洞,进一步破坏了基体结构。CCUS technology,as an important emerging technology for controlling greenhouse effects and achieving sustainable development of human society,has gradually received widespread attention from the international community.However,during the process of CO_(2) injection and storage,long-term contact between cement and CO_(2) will cause CO_(2corrosion) problem,resulting in the destruction of the structural integrity of the cement stone.In order to investigate the carbonation corrosion process of G-class oil well cement at di?erent temperatures in a CO_2-rich underground environment,this study analyzed it using microscopic tests such as XRD,TG/DTG,FTIR and SEM.The results indicate that a large amount of calcite and aragonite are formed after carbonization of cement stone at different temperatures,and calcite dominates.With the increases of carbonization temperature and age,both C-S-H gel and CH of cement paste participate in the carbonization reaction.The content of calcite and aragonite in the sample gradually increases,and the degree of carbonization deepens.With the increases of carbonization temperature and age,C-S-H gel and CH gradually transform into CaCO_(3) crystals,leading to a volume change.As the CaCO_(3) crystals gradually develop and grow,the cement stone matrix will expand internally,forming numerous cracks and pores,further damaging the matrix structure.

关 键 词：油井水泥 CCUS 碳化 碳化产物 

分 类 号：TQ172.75[化学工程—水泥工业] TE256[化学工程—硅酸盐工业]