CO₂-rock wettability is a key factor which determines the fluid dynamics and CO₂ geo-storage capacity. However, the full understanding of real reservoir CO₂-wettability is yet to be gained. We thus systematically analysed the wettability of CO₂/brine/South West Hub sandstones at various pressures (0.1 MPa, 5 MPa, 10 MPa, 15 MPa, and 20 MPa) at 334 K. A new procedure based on organic carbon isotope tracking (δ¹³C_org) was proposed to eliminate the effect of artificial organic matter introduced by drilling mud penetration. The results indicate that the advancing (θ_a) and receding (θ_r) water contact angles for the CO₂/brine/South West Hub sandstone system increase with increase in pressure (ranging from 71° to 118° and 66° to 111°). It can thus be suggested that the system is weakly water-wet to intermediate-wet. When the samples were treated with dichloromethane, a slight decline in organic content was observed leading to slight decrease in water contact angles (i.e. TOC decreased from 0.019% to 0.003% for core C, and the corresponding θ_a and θ_r decreased from 118° and 111° to 110° and 104°, respectively, at 20 MPa and 334 K). This wettability analysis demonstrates that (a) of the contact angle is very sensitive to the amount of organic matter and therefore care should be taken to remove artificial organic matter from the sample, and that (b) this condition prevails in a real proposed CO₂-storage site. This analysis thus has important implications for assessing the feasibility of long-term CO₂ storage and enabling large-scale industrial carbon geological storage projects.

CO ₂岩石的润湿性是决定流体动力学和CO ₂地质储存能力的关键因素。然而，尚未获得对实际储层CO ₂润湿性的完全理解。因此，我们系统地分析了在334 K下各种压力（0.1 MPa，5 MPa，10 MPa，15 MPa和20 MPa）下CO ₂ /盐水/西南毂砂岩的润湿性。一种基于有机碳同位素追踪的新程序（δ ¹³ ç_有机），提出了以消除通过钻孔泥浆渗透引入人工有机物的效果。结果表明，推进（θ_一）和后退（θ _ř）CO ₂ /盐水/西南枢纽砂岩系统的水接触角随压力的增加而增加（范围从71°到118°，从66°到111°）。因此可以建议该系统是弱水湿到中等湿的。当样品用二氯甲烷处理，观察到有机含量略有下降导致轻微降低的水接触角（即TOC从0.019％降低到0.003％为芯部C，相应的θ_一个和θ _ř在20 MPa和334 K时分别从118°和111°降至110°和104°）。该润湿性分析表明，（a）接触角对有机物的量非常敏感，因此应注意从样品中去除人造有机物，并且（b）在实际提出的CO _2中普遍存在这种情况-存储站点。因此，该分析对评估长期CO ₂储存的可行性以及实现大规模工业碳地质储存项目具有重要意义。