Carbon dioxide geo-sequestration (CGS) into sediments in the form of (gas) hydrates is one proposed method for reducing anthropogenic carbon dioxide emissions to the atmosphere and, thus reducing global warming and climate change. However, there is a serious lack of understanding of how such CO₂ hydrate forms and exists in sediments. We thus imaged CO₂ hydrate distribution in sandstone, and investigated the hydrate morphology and cluster characteristics via x-ray micro-computed tomography in 3D in-situ. A substantial amount of gas hydrate (∼17% saturation) was observed, and the stochastically distributed hydrate clusters followed power-law relations with respect to their size distributions and surface area-volume relationships. The layer-like hydrate configuration is expected to reduce CO₂ mobility in the reservoir, and the smaller than expected hydrate surface-area/volume ratio will reduce methane production and CO₂ storage capacities. These findings will aid large-scale implementation of industrial CGS projects via the hydrate route.

二氧化碳地质封存（CGS）以（气体）水合物的形式沉积到沉积物中是减少人为的二氧化碳排放到大气中，从而减少全球变暖和气候变化的一种建议方法。然而，严重缺乏对这种CO ₂水合物如何形成和存在于沉积物中的认识。因此，我们对CO _2进行了成像水合物在砂岩中的分布，并通过X射线微计算机断层扫描技术在3D原位研究了水合物的形态和团簇特征。观察到大量的天然气水合物（饱和度约为17％），并且随机分布的水合物团簇的大小分布和表面积-体积关系遵循幂律关系。预期层状水合物的构型将降低储层中的CO ₂迁移率，小于预期的水合物表面积/体积比将降低甲烷产量和CO ₂储存能力。这些发现将有助于通过水合物途径大规模实施工业CGS项目。