Temperature dependence of hydrogen diffusion in reservoir rocks: implications for hydrogen geologic storage
由于可再生能源（绿色氢气的来源）的间歇性，需要在地下地质构造中临时储存氢气。为了量化储存潜力和泄漏风险，全面表征地下氢气传输行为至关重要。本研究旨在测量氢气通过相关储层岩石（包括两种砂岩和一种石灰岩）的扩散，并测量不同温度下的突破曲线，以计算有效扩散系数和扩散活化能。
研究结果表明，氢气扩散会略微扩大储层中的氢气羽流尺寸，最大可达7%，且这种影响在低含水饱和度的储层中最为显著。研究还发现，使用垫气可以维持储层压力并提高注入效率，但如果垫气与氢气不同，分子扩散可能会扩大氢气羽流并阻碍回采过程。通过实验测量的氢气扩散系数为地质条件下地下储层岩石中氢气扩散提供了基础数据，对于优化地质氢储存和回采过程具有重要意义。
CMG软件应用情况
在本研究中，CMG GEM软件被用于模拟地质氢储存过程中的氢气羽流迁移行为。研究通过模拟两种储层（砂岩和碳酸盐岩）中的氢气储存，评估了氢气扩散对羽流尺寸的影响。模拟考虑了储层的渗透率、孔隙度、初始含水饱和度等参数，并假设储层具有良好的盖层完整性。CMG软件的使用为研究提供了详细的羽流迁移数据，帮助研究人员更好地理解地质氢储存过程中的流体动力学行为。
Abstract
Hydrogen (H2) has recently gained momentum as a promising clean energy alternative to fossil fuels. The intermittent nature of renewable energy, as the source of green H2, necessitates temporary H2 storage in subsurface geologic formations. To quantify storage potential and leakage risk, it is crucial to fully characterize subsurface H2 transport behavior. This work aims to measure the diffusion of H2 through relevant reservoir rocks, including two sandstones (Amherst Grey and Birmingham) and a limestone (Indiana). Breakthrough as a function of temperature is measured and used to calculate the effective diffusion coefficients and activation energy for diffusion at three different temperatures between 20 and 75 1C. Calculated diffusion coefficients are then used to estimate the subsurface plume size during storage in sandstone and limestone reservoirs. We observe that diffusive flow slightly expands plume size by up to 7%, and this effect is most pronounced in formations with low water saturation. While the use of cushion gas can maintain reservoir pressure and enhance injection efficiency, it can also enlarge H2 plume and hinder the recovery process due to molecular diffusion if the cushion gas differs from H2.
作者单位
- 美国洛斯阿拉莫斯国家实验室能源与自然资源安全小组
- 宾夕法尼亚州立大学能源与矿物工程系
