A diffusion-reaction model for the carbonation process of oilwell cement exposed to carbonated brine under CO₂ geological storage conditions is presented. The formulation consists of two main diffusion/reaction field equations for the concentrations of aqueous calcium and carbon species in the pore solution of the hardened cement paste, complemented by two diffusion-only field equations for chloride and alkalis concentrations, and by a number of chemical kinetics and chemical equilibrium equations. The volume fraction distribution of the solid constituents of the hardened cement paste and the reaction products evolve with the progress of the reaction, determining the diffusivity properties of the material. The model is used to simulate experimental tests performed by Duguid and Scherer (2010), leading to promising results indicating that the fundamental aspects of the phenomenon are captured.

CO ₂下暴露于碳酸盐水的油井水泥碳化过程的扩散反应模型介绍了地质储藏条件。该配方由两个主要的扩散/反应场方程组成，用于计算硬化水泥浆孔隙溶液中钙和碳的含量，另外还包括两个仅扩散场方程，用于计算氯化物和碱的浓度，以及多种化学物质。动力学和化学平衡方程式。硬化水泥浆和反应产物的固体成分的体积分数分布随着反应的进行而变化，从而决定了材料的扩散性能。该模型用于模拟Duguid和Scherer（2010）进行的实验测试，得出的结果令人鼓舞，表明该现象的基本方面已被捕获。