Structural trapping is the primary CO₂ geo-storage mechanism, and it has historically been quantified by CO₂ column heights, which can be permanently immobilized beneath a caprock, using a buoyancy force-capillary force balance. However, the high dependence of CO₂-wettability (a key parameter in the above analysis) on pressure and temperature – and thus storage depth – has not been taken into account. Importantly, rock can be CO₂-wet at high pressure, and this wettability reversal results in zero structural trapping below a certain storage depth (∼2400 m maximum caprock depth for a most likely scenario is estimated here). Furthermore, more relevant than the CO₂ column height is the actual mass of CO₂ which can be stored by structural trapping (m_CO2). This aspect has now been quantified here, and importantly, m_CO2 goes through a maximum at ∼1300 m depth, thus there exists an optimal storage depth at around 1300 m depth.

结构性捕集是主要的CO ₂地质存储机制，历史上已经通过CO ₂柱高进行了量化，可以使用浮力-毛细管力平衡将其永久固定在盖层下方。但是，尚未考虑到CO _2的润湿性（上述分析中的关键参数）对压力和温度以及存储深度的高度依赖性。重要的是，岩石在高压下可能是CO ₂润湿的，而这种可湿性反转导致在一定的存储深度以下（此处估计最可能的情况下的最大盖层深度约为2400 m），零结构圈闭。此外，比CO ₂色谱柱高度更重要的是CO的实际质量₂可以通过结构性捕集（m _CO2）进行存储。现在已对此方面进行了量化，重要的是，m _CO2在约1300 m深度处经历了最大值，因此在1300 m深度附近存在最佳存储深度。