Abstract Reactive transport modeling is an essential tool to simulate complex geochemical reactions in porous media that can impact formation properties including porosity and permeability. However, simulating these reactions is challenging due to uncertainties in model parameters, particularly mineral surface areas. Imaging has emerged as a powerful means of estimating model parameters including porosity and mineral abundance, accessibility and accessible surface area. However, these parameters, particularly mineral accessible surface area, vary with image resolution. This work aims to enhance understanding of the impact of image resolution and other means of estimating mineral reactive surface area on simulated mineral reactions and reaction rates. Mineral surface areas calculated from images with resolutions of 0.34 μm and 5.71 μm were used to simulate mineral reactions in the context of geologic CO2 sequestration in the Paluxy formation at the continuum scale. Additional simulations were carried out using BET surface areas collected from the literature and geometric surface areas. Simulations were run for 7300 days and mineral volume fractions and effluent ion concentrations tracked and compared. Variations in mineral surface areas measured from images are within 1 order of magnitude and yield similar simulation results, indicating the impact of image resolution on simulated reactions and reaction rates is minimum for the resolutions and sample considered. In comparison, surface areas obtained from BET and geometric approaches are 1-4 orders of magnitude higher than image-obtained surface areas and result in greater simulated reaction rates and extents. Minerals with high reaction rates (calcite and siderite) are most impacted by surface area values at short times where simulated mineral volume fractions at longer times agree relatively well, even for simulations with several orders of magnitude variation in surface area. Phases with lower reaction rates, such as K-feldspar and muscovite, are predominantly impacted over longer times where variations in surface areas impact reaction extents and porosity evolution. Overall, variations in surface areas due to image resolution are small and result in little variation in simulated reactions and reaction rates while there are significant variations in simulation results when other surface area estimates are used. These variations, however, depend on the reactivity of the mineral phase where surface areas of fast-reacting phases largely impact simulations at short (hours to days) timescales and surface areas of slower-reactive phases impact longer term simulations (years).

中文翻译：

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矿物反应表面积变化对模拟矿物反应和反应速率的影响

摘要 反应输运建模是模拟多孔介质中复杂地球化学反应的重要工具，这些反应会影响地层特性，包括孔隙度和渗透率。然而，由于模型参数的不确定性，特别是矿物表面积，模拟这些反应具有挑战性。成像已成为估算模型参数（包括孔隙度和矿物丰度、可达性和可达表面积）的有力手段。然而，这些参数，尤其是矿物可及表面积，随图像分辨率而变化。这项工作旨在增强对图像分辨率和其他估算矿物反应表面积的方法对模拟矿物反应和反应速率的影响的理解。根据分辨率为 0.34 μm 和 5 的图像计算的矿物表面积。71 μm 用于模拟连续介质尺度下 Paluxy 地层地质 CO2 封存背景下的矿物反应。使用从文献中收集的 BET 表面积和几何表面积进行了额外的模拟。模拟运行了 7300 天，跟踪和比较了矿物体积分数和流出物离子浓度。从图像测量的矿物表面积的变化在 1 个数量级内并产生类似的模拟结果，表明图像分辨率对模拟反应和反应速率的影响对于所考虑的分辨率和样品是最小的。相比之下，从 BET 和几何方法获得的表面积比图像获得的表面积高 1-4 个数量级，并导致更大的模拟反应速率和范围。具有高反应速率的矿物（方解石和菱铁矿）在短时间内受表面积值的影响最大，在较长时间内模拟的矿物体积分数相对吻合，即使对于表面积有几个数量级变化的模拟也是如此。反应速率较低的相，如钾长石和白云母，主要受到较长时间的影响，其中表面积的变化会影响反应程度和孔隙度演变。总体而言，由于图像分辨率导致的表面积变化很小，导致模拟反应和反应速率的变化很小，而当使用其他表面积估计值时，模拟结果存在显着差异。然而，这些变化，