In this work, a water chemistry model was developed by combining the activity coefficient-fugacity coefficient type solubility model and species equilibrium model to determine the mutual solubilities of CO₂ and H₂O, and the corresponding species concentrations in the CO₂-mixed salts-H₂O system (mainly contains Na⁺, Ca²⁺, Mg²⁺, K⁺, Cl^-, and SO₄^2-) with the temperature range of 15–250 °C, the pressure range of 1–600 bar and the salt molality range of 0–6 mol/kg. The computed solubilities of CO₂ and H₂O, and pH values show a good agreement with the experimental data in the literature, which indicates the high accuracy and accessibility of this water chemistry model. Based on this accurate water chemistry model, a comprehensive mechanistic model was established to predict the corrosion of carbon steel in supercritical CO₂-containing formation water based on finite element method. The modeling corrosion rate agrees well with the measured corrosion rate.

在这项工作中，通过结合活度系数-逸度系数类型溶解度模型和物种平衡模型来确定水化学模型，以确定 CO ₂和 H ₂ O 的互溶度，以及 CO ₂混合盐中相应的物种浓度-H ₂ O 系统（主要包含 Na ⁺、Ca ²⁺、Mg ²⁺、K ⁺、Cl ^-和 SO ₄ ^2-），温度范围为 15–250 °C，压力范围为 1–600 bar盐摩尔浓度范围为 0-6 mol/kg。CO ₂和 H ₂的计算溶解度O 和 pH 值与文献中的实验数据显示出良好的一致性，表明该水化学模型具有较高的准确性和可访问性。基于这种精确的水化学模型，基于有限元方法，建立了预测碳钢在超临界含CO ₂地层水中腐蚀的综合机理模型。建模腐蚀速率与测量腐蚀速率非常吻合。