标题： 地下燃气储存中的奥斯特瓦尔德熟化 显示英文标题

标题： Ostwald Ripening in Underground Gas Storage

摘要： 地下气体储存是气候缓解和能源转型战略的核心，支持长期碳封存和季节性氢气储存。 控制注入气体命运的关键机制是奥斯特瓦尔德熟化，这是多孔介质中被俘气体聚集体之间的曲率驱动质量传递。 虽然在开放系统中熟化过程已被充分理解，但在几何受限的多孔结构中的行为仍缺乏明确描述，尤其是在与地下操作相关的长时间尺度上。 在此，我们介绍了超高分辨率的微流体实验，在定义明确的边界条件下，捕捉了真实、非均质孔隙几何结构中残余氢气在数周内的演化过程。 我们观察到一种明显的两阶段动态：相邻气泡之间的快速局部平衡，随后是由长距离扩散向低化学势边界驱动的缓慢全局消耗。 基于这些见解，我们开发并验证了一个连续体模型，该模型将通过孔隙形态方法提取的微观毛管压力-饱和度（Pc-s）关系与宏观扩散传输耦合。 该模型无需拟合参数即可准确预测气体饱和度的演化，并将不同实验条件下的实验结果统一起来。 将模型扩展到储层尺度，我们估算了CO2和H2在均质砂岩含水层中的平衡时间尺度。 我们发现，在CO2封存中，熟化过程比对流溶解快得多，而在时间尺度上与季节性H2储存操作相当。 这些发现建立了一个定量框架，将孔尺度的异质性与场地尺度的气体再分布联系起来，对地下储存策略的设计和持久性具有重要意义。 显示英文摘要

摘要： Underground gas storage is central to both climate mitigation and energy transition strategies, supporting both long-term carbon sequestration and seasonal hydrogen storage. A key mechanism governing the fate of injected gases is Ostwald ripening, the curvature-driven mass transfer between trapped gas ganglia in porous media. While ripening is well understood in open systems, its behavior in geometrically confined porous structures remains poorly characterized, especially over long timescales relevant to subsurface operations. Here, we present ultra-high-resolution microfluidic experiments that capture the evolution of residually trapped hydrogen over weeks in realistic, heterogeneous pore geometries under well-defined boundary conditions. We observe a distinct two-stage dynamic: a rapid local equilibration among neighboring bubbles, followed by slow global depletion driven by long-range diffusion toward low-chemical potential boundaries. Building on these insights, we develop and validate a continuum model that couples microscale capillary pressure-saturation (Pc-s) relationships, extracted via the pore-morphology method, with macroscopic diffusive transport. The model accurately predicts gas saturation evolution without fitting parameters and collapses experimental results across a range of experimental conditions. Extending the model to reservoir scales, we estimate equilibration timescales for CO2 and H2 in homogeneous sandstone aquifers. We find that ripening occurs much faster than convective dissolution in CO2 sequestration, and on timescales comparable to seasonal H2 storage operations. These findings establish a quantitative framework linking pore-scale heterogeneity to field-scale gas redistribution, with implications for the design and longevity of subsurface storage strategies.