Saline aquifer storage is considered to be a promising method of carbon dioxide (CO₂) mitigation. The CO₂–brine interfacial tension (IFT) and the caprock wettability under reservoir temperature and pressure conditions are essential for storage capacity estimation. In this study, the CO₂–brine (NaCl + KCl) IFTs were obtained by using the pendant drop method under 298–373 K temperature, 3–15 MPa pressure, and 1.0–4.9 mol·kg⁻¹ salinity. A detailed analysis of the relationship of IFT with temperature, pressure, and salinity was conducted. In addition, an empirical equation was developed to estimate the CO₂–brine IFTs in a wide range of temperatures, pressures, and salt molality. The contact angles (CAs) of brine on quartz, Berea Sandstone, and limestone surfaces in the presence of supercritical, liquid, and gaseous CO₂ were measured by using the sessile drop method, and the wettability alteration of the rock surfaces in the presence of supercritical CO₂ was systematically investigated. According to the results, the CO₂–brine IFTs increased with salinity and temperature and decreased with pressure until reaching a plateau. For a CO₂–mixed brine system, a linear relationship between the IFT increase ($\mathrm{\Delta }\gamma$) and molality was observed. The CAs of the different rock samples varied with temperature and pressure. However, all the three rock samples became less water-wet when the CO₂ phase state changed from subcritical to supercritical.

盐水储存被认为是减少二氧化碳（CO ₂）的一种有前途的方法。在储层温度和压力条件下，CO _2-盐水界面张力（IFT）和盖层润湿性对于估算储量至关重要。在这项研究中，使用悬滴法在298–373 K温度，3–15 MPa压力和1.0–4.9 mol·kg ^-1盐度下，采用悬滴法获得了CO _2-盐水（NaCl + KCl）IFT 。对IFT与温度，压力和盐度的关系进行了详细分析。此外，还建立了一个经验方程来估算CO _2。–各种温度，压力和盐摩尔浓度下的盐水IFT。采用无滴法测量了盐水在超临界，液态和气态CO ₂存在下在石英，Berea砂岩和石灰石表面上的接触角（CAs），并在存在超临界CO2的情况下测量了岩石表面的润湿性变化。系统地研究了超临界CO ₂。根据结果​​，CO _2-盐水IFTs随着盐度和温度的升高而增加，而随着压力的降低而降低，直至达到平稳状态。对于CO ₂混合盐水系统，IFT增加之间的线性关系（$\mathrm{\Delta }\gamma$），并观察到摩尔浓度。不同岩石样品的CA随温度和压力而变化。但是，当CO ₂相态从亚临界转变为超临界时，这三个岩石样品的水润湿性都降低了。