HCl is generated in subsurface brines exposed to high CO₂ pressures via reactions such as CO₂ + NaCl + H₂O ↔ NaHCO₃ + HCl. The extent of partitioning of HCl between a concentrated chloride brine and supercritical CO₂ (scCO₂) has not been measured before and it cannot be estimated with the accuracy sufficient for predictive modeling of subsurface processes. The partitioning of HCl between 4.92 mol/kg aqueous solutions of NaCl and scCO₂ was measured at 100 and 150 °C and at pressures between 9 and 16.2 MPa. At P = 15 MPa, the concentrations of HCl in the scCO₂ phase were 7 × 10^–4 and 4 × 10^–3 mol/L at 100 and 150 °C, an increase by more than 5 and 3 orders of magnitude, respectively, relative to the concentrations in water vapor in the absence of CO₂. These levels of HCl may accelerate reactions with reservoir rocks, natural seals (shale caprocks) and downhole materials, potentially enhancing or impairing operation and long-term performance of subsurface technologies such as geologic carbon sequestration/storage, enhanced geothermal systems using compressed CO₂, and scCO₂ extraction of hydrocarbons, and other resources in the presence of chloride brines.

中文翻译：

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地质储层条件下HCl在浓盐水和超临界CO ₂之间的分配

在暴露于高CO ₂压力的地下盐水中，通过诸如CO ₂ + NaCl + H ₂ O↔NaHCO ₃ + HCl的反应生成HCl。之前尚未测量HCl在浓氯化物盐水和超临界CO ₂（scCO ₂）之间的分配程度，并且无法以足以用于地下过程预测模型的准确性进行估算。在100和150°C以及9和16.2 MPa之间的压力下，测量了HCl在4.92 mol / kg NaCl和scCO ₂水溶液之间的分配。在P = 15 MPa时，scCO ₂相中的HCl浓度为7×10 ^–4与在100和150°C下4×10 ^–3 mol / L相比，在没有CO ₂的情况下，水蒸气的浓度分别增加了5个和3个数量级以上。这些HCl含量可能会加速与储层岩石，天然封闭层（页岩盖层）和井下材料的反应，潜在地增强或削弱地下技术的运行和长期性能，例如地质碳封存/存储，使用压缩CO _2的增强地热系统，在氯化盐水的存在下，用scCO ₂提取碳氢化合物和其他资源。