Relative permeability of supercritical CO₂ (scCO₂) and brine was determined in reactive and non-reactive rock cores using a combination of unsteady-state methodology and computed tomography. Experiments were conducted using a medical grade CT scanner to determine saturation using a custom Python script. The saturation and differential pressure across the core were then used to derive four empirical constants to calculate relative permeability. This methodology increases temporal efficiency while reducing experimental complexity. Additionally, we show that the method can be used to determine scCO₂ relative permeability in a wide range of lithologies and flow rates, and with the ability to account for matrix dissolution during scCO₂ flooding.

Plain Language Summary

: The ability to capture and store carbon dioxide (CO₂) is an important component of efforts to slow climate change. Long-term geologic storage of CO₂ requires accurate descriptions of injected CO₂ in subsurface rock formations to account for stored volumes and develop adequate risk monitoring. Effectively describing the migration of CO₂ injected in underground reservoirs requires an accurate description of how CO₂ moves and interacts with the rock. Relative permeability, or the description of how efficiently a fluid moves in a porous media while in the presence of other fluids, is the most utilized tool for describing the competitive flow of fluids. In this study, we detail a modified unsteady-state methodology using computed tomography that provides relative permeability quickly and can be used to analyze heterogenous media. The methodology can be used to describe the impacts of dissolution on CO₂ transport through reactive cores, which to the authors knowledge, has not been described in the literature previously.

中文翻译：

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使用非稳态流动法快速测定超临界 CO ₂和盐水相对渗透率

超临界 CO ₂ (scCO ₂ ) 和盐水的相对渗透率在反应性和非反应性岩心中使用非稳态方法和计算机断层扫描相结合来确定。实验是使用医疗级 CT 扫描仪进行的，以确定使用自定义 Python 脚本的饱和度。然后使用穿过岩心的饱和度和压差推导出四个经验常数来计算相对渗透率。这种方法提高了时间效率，同时降低了实验的复杂性。此外，我们表明该方法可用于确定各种岩性和流速下的scCO ₂相对渗透率，并且能够解释 scCO ₂过程中的基质溶解 洪水。

简明语言摘要

：捕获和储存二氧化碳 (CO ₂ ) 的能力是减缓气候变化努力的重要组成部分。CO ₂的长期地质储存需要对地下岩层中注入的 CO ₂进行准确描述，以说明储存量并进行充分的风险监测。有效地描述注入地下储层的 CO ₂的运移需要准确描述 CO ₂移动并与岩石相互作用。相对渗透率，或描述流体在多孔介质中在其他流体存在的情况下如何有效移动，是描述流体竞争流动的最常用工具。在这项研究中，我们详细介绍了一种使用计算机断层扫描的改进非稳态方法，该方法可以快速提供相对渗透率并可用于分析非均质介质。该方法可用于描述溶解对通过反应性岩心传输的CO ₂的影响，据作者所知，这在以前的文献中没有描述过。