Formation dry‐out in fracture‐dominated geological reservoirs may alter the fracture space, impair rock absolute permeability, and cause a significant decrease in well injectivity. In this study, we numerically model the dry‐out processes occurring during supercritical CO₂ (scCO₂) injection into single brine‐filled fractures and evaluate the potential for salt precipitation under increasing effective normal stresses in the evaporative regime. We use an open‐source, parallel finite‐element framework to numerically model two‐phase flow through 2‐D fracture planes with aperture fields taken from naturally fractured granite cores at the Grimsel Test Site in Switzerland. Our results reveal a displacement front and a subsequent dry‐out front in all simulated scenarios, where higher effective stresses caused more flow channeling, higher rates of water evaporation, and larger volumes of salt precipitates. However, despite the larger salt volumes, the permeability impairment was lower at higher effective normal stresses. We conclude that the spatial distribution of the salt, precipitated in fractures with heterogeneous aperture fields, strongly affects the absolute permeability impairment caused by formation dry‐out. The numerical simulations assist in understanding the behavior of the injectivity in fractures and fracture networks during subsurface applications that involve scCO₂ injection into brine.

中文翻译：

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将CO2注入单个天然盐水填充的裂缝中的渗透性损害和盐析出模式

在以裂缝为主的地质储层中，地层变干可能会改变裂缝空间，损害岩石的绝对渗透率，并导致井眼注入量显着下降。在这项研究中，我们对超临界CO ₂（scCO ₂）注入单个充满盐水的裂缝中，并评估在蒸发条件下有效法向应力增加时盐析的可能性。我们使用开放源代码的并行有限元框架，对通过二维断裂面的两相流进行数值模拟，其孔径场取自瑞士格里姆瑟尔试验场的天然断裂花岗岩芯。我们的结果显示，在所有模拟情况下，位移前沿和随后的干燥前沿都存在，其中较高的有效应力导致更多的水流通道，较高的水蒸发速率和较大的盐析出量。但是，尽管盐量较大，但在较高的有效法向应力下渗透性损害较小。我们得出结论，盐的空间分布 沉积在具有非均质孔径场的裂缝中，严重影响由地层变干引起的绝对渗透率损害。数值模拟有助于了解涉及scCO的地下应用中裂缝和裂缝网络中注入的行为₂注入盐水。