Quantification of the Impact of Acidified Brine on Fracture-Matrix Transport in a Naturally Fractured Shale Using in Situ Imaging and Modeling
Quantification of the Impact of Acidified Brine on Fracture-Matrix Transport in a Naturally Fractured Shale Using in Situ Imaging and Modeling
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DOI：
10.1021/acs.energyfuels.3c01463
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发表时间：
2023-07
期刊：
影响因子：
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通讯作者：
C. Zahasky;M. P. Murugesu;T. Kurotori;Collin R. Sutton;J. Druhan;B. Vega;S. Benson;A. Kovscek
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文献类型：
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作者：
C. Zahasky;M. P. Murugesu;T. Kurotori;Collin R. Sutton;J. Druhan;B. Vega;S. Benson;A. Kovscek
13了解断裂地质材料中的流动、运输、化学反应和水力机械过程是优化一系列地下过程的关键，包括二氧化碳和氢的储存、非常规能源资源的开采和地热能的回收。由于实验的复杂性和量化连续尺度描述微米级裂缝和纳米级孔隙之间的质量交换的多尺度性质，天然裂缝页岩中的流动和运输过程一直具有挑战性。在这项研究中，我们使用正电子发射断层扫描（PET）对天然裂缝沃尔夫坎普页岩岩芯暴露于低pH盐水条件之前和之后保守示踪剂在岩芯中的传输进行成像。基于图像的实验观测解释拟合的分析运输模型，以在核心中的含钙体素。该分析的结果表明，在暴露于低pH值条件下，基质扩散率和稍微更均匀的断裂速度分布略有增加。这些意见进行了比较，多组分的一维反应性运输模型，表明在孔隙度增加10%的能力，作为结果的低pH值的盐水暴露在多孔质-基质界面。这
13 Understanding flow, transport, chemical reactions, and hydro-mechanical processes in fractured geologic materials is key for optimizing a range of subsurface processes including carbon dioxide and hydrogen storage, unconventional energy resource extraction, and geothermal energy recovery. Flow and transport processes in naturally fractured shale rocks have been challenging to characterize due to experimental complexity and the multiscale nature of quantifying continuum scale descriptions of mass exchange between micrometer-scale fractures and nanometer-scale pores. In this study, we use positron emission tomography (PET) to image the transport of a conservative tracer in a naturally fractured Wolfcamp shale core before and after exposure of the core to low pH brine conditions. Image-based experimental observations are interpreted by fitting an analytical transport model to fracture-containing voxels in the core. Results of this analysis indicate subtle increases in matrix diffusivity and a slightly more uniform fracture velocity distribution following exposure to low pH conditions. These observations are compared with a multi-component one-dimensional reactive transport model that indicates the capacity for a 10% increase in porosity at the fracture-matrix interface as a result of the low pH brine exposure. This