To make natural gas hydrate an energy source available for large-scale applications, some issues must be solved; amongst them, the low kinetic characterizing the process and re-formation of methane hydrate are the most significant. In this paper methane and carbon dioxide hydrate formation was tested in presence of a natural silica-based porous sand, with the aim of define the most useful pressure value for carbon dioxide injection into reservoirs in order to apply replacement strategies via depressurization. A direct comparison between CO2 hydrate formation tests starting respectively from 30 bar and 40 bar, revealed that this latter solution represents the most effective solution. While moles of CO2 involved into hydrate and, more in general, moles of CO2 permanently stored, are similar in both typologies of tests, the time necessary to complete the formation process was drastically lower in tests started from 40 bar. Moreover, a lower pressure drop would be required. The more effective kinetic of the process and the negligible risk of methane hydrate re-formation verified during experiments, allowed to consider the CO2 injection into the reservoir at 40 bar the best solution to optimize methane recovery, carbon dioxide storage and seafloor deformations due to the reservoir exploitation.

要使天然气水合物成为可用于大规模应用的能源，必须解决一些问题；其中，甲烷水合物过程和再形成的低动力学特征最为显着。在本文中，在天然二氧化硅基多孔砂的存在下测试了甲烷和二氧化碳水合物的形成，目的是确定二氧化碳注入储层的最有用的压力值，以便通过减压应用替代策略。分别从 30 bar 和 40 bar 开始的 CO2 水合物形成测试之间的直接比较表明，后一种解决方案代表了最有效的解决方案。虽然进入水合物的 CO2 摩尔数，更一般地说，永久储存的 CO2 摩尔数，在两种类型的测试中是相似的，在从 40 bar 开始的测试中，完成形成过程所需的时间大大减少。此外，将需要较低的压降。该过程的更有效动力学和实验期间验证的甲烷水合物再形成风险可忽略不计，允许考虑在 40 bar 压力下将 CO2 注入储层，这是优化甲烷回收、二氧化碳储存和海底变形的最佳解决方案。油藏开采。