Review of the Behavior of Geopolymer Cement Exposed to Acidic Environment Under CO₂ Sequestration Conditions

Geopolymer cement is a promising alternative to wellbore cement for applications involving acidic environments, particularly in CO₂ sequestration wells. Its unique structure characterized by low Ca/Si ratio, low calcium content, and a highly cross-linked aluminosilicate gel matrix, provides superior resistance to chemical degradation, reduced permeability, and stable mechanical properties under high temperature and pressure conditions. The paper provides a review of the recent research on geopolymer cement use for applications of CO₂ sequestration, it compares the chemistry of the wellbore cement (i.e. such as Class G cement) with that of geopolymer, it deeply compares that chemistry and investigate its impact on the stability of the cementitious materials developed in both systems in CO₂-rich environment. It also discussed microstructural behavior of both geopolymer based cement and wellbore cement in CO₂-rich environment and compare the long-term stability of both systems in such harsh conditions. This review shows that Geopolymer cement matrix has a unique chemistry as characterized by low calcium content which make it more stable in harsh conditions compared to wellbore cement. In terms of durability, geopolymer cement also showed long-term stability in acidic conditions. On the other hand, these geopolymer materials need standardization and also there is no any reported field application of such geopolymer cement especially in acidic environments such as CO₂ storage sites.