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Abstract 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 CO2 injection and storage, long-term contact between cement and CO2 will cause CO2 corrosion 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 different temperatures in a CO2-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 CaCO3 crystals, leading to a volume change. As the CaCO3 crystals gradually develop and grow, the cement stone matrix will expand internally, forming numerous cracks and pores, further damaging the matrix structure.
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Published: 28 November 2024
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2024, Vol. 0 
