基于micro-CT扫描的孔裂隙结构表征及渗流模拟
Characterization of pore-fracture structure and seepage simulation based on micro-CT scanning
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摘要: 以羊场湾不粘煤为研究对象，基于micro-CT扫描实验和Avizo处理软件，对煤中孔裂隙、矿物质以及煤基质进行精确提取与分割，并通过三维重构技术，得到了连通孔裂隙模型；在此基础上，进一步建立了具有孔裂隙形态学拓扑结构的等效孔隙网络模型，统计分析了煤中孔喉结构参数，包括孔隙半径、孔隙体积、喉道半径、喉道长度以及配位数；基于孔隙尺度的渗流模拟，实现了孔裂隙空间单相水的可视化渗流过程，并计算了3个方向的绝对渗透率。研究结果表明：羊场湾不粘煤中以片状孔隙群和大尺度互相垂直的裂隙发育为主，平均孔隙半径和喉道半径分别为106、27.79 μm，平均配位数为3.45；在单相水渗流过程中，孔裂隙空间内的渗流速度明显高于流入流出端，3个方向的渗透率表现出明显的各向异性，其中y方向的绝对渗透率数值最大，x方向的渗透率最小。Abstract: Taking the non-stick coal from Yangchangwan Coal Mine as the research object, based on the micro-CT scanning experiment and Avizo processing software, the pore-fracture, minerals and coal matrix of the coal are accurately extracted and segmented. Through the three-dimensional reconstruction technology, the connected pores and fracture models are obtained. On this basis, an equivalent pore network model（PNM）with the morphological topological structure of pores and fractures was further established, and the pore-throat structure parameters in the coal were statistically analyzed, including pore radius, pore volume, throat radius, throat length, and coordination number. Based on the pore-scale seepage simulation, the visualization seepage of single-phase water in the pore-fracture space was realized, and the absolute permeability in three directions was calculated. The results show that the Yangchangwan non-stick coal is dominated by flaky pore clusters and large-scale vertical fractures. The average pore radius and throat radius is 106 μm and 27.79 μm, respectively, and the average coordination number is 3.45. In the process of single-phase water seepage, the seepage velocity in the pore-fracture space is higher than that of the outlet and inlet, and the permeability in the three directions shows obvious anisotropy. Among them, the absolute permeability value in the y direction is the largest, and in the x direction is the smallest.
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[1] 叶桢妮，侯恩科，段中会，等.不同煤体结构煤的孔隙裂隙分形特征及其对渗透性的影响[J].煤田地质与勘探，2019，47（5）：70-78. YE Zhenni, HOU Enke, DUAN Zhonghui, et al. Fractal characteristics of pores and microfractures of coals with different structure and their effecton permeability[J].Coal Geology & Exploration, 2019, 47（5）: 70-78.
[2] 金毅，宋慧波，潘结南，等.煤微观结构三维表征及其孔-渗时空演化模式数值分析[J].岩石力学与工程学报，2013，32（S1）：2632-2641. JIN Yi, SONG Huibo, PAN Jienan, et al. Three-dimensional representation of coal’s microstructure and numerical analysis of its pore-permeability spatial-temporal evolution mode[J]. Chinese Journal of Rock Mechanics and Engineering, 2013, 32（S1）: 2632-2641.
[3] FAN Nan, WANG Jiren, DENG Cunbao, et al. Quantitative characterization of coal microstructure and visualization seepage of macropores using CT-based 3D reconstruction[J]. Journal of Natural Gas Science and Engineering, 2020, 81: 103384. [4] 宋洪庆，朱维耀，王一兵，等.煤层气低速非达西渗流解析模型及分析[J].中国矿业大学学报，2013，42（1）：93-99. SONG Hongqing, ZHUWeiyao, WANGYibing, et al. Analytical model of low velocity non-Darcy flow of coalbed methane and its analysis[J]. Journal of China University of Mining & Technology, 2013, 42（1）: 93-99.
[5] 吕兆兴，冯增朝，赵阳升，等.孔隙裂隙双重介质的三维逾渗数值模拟研究[J].岩土力学，2007，28（S1）：291-294. LU Zhaoxing, FENG Zengchao, ZHAO Yangsheng, et al. Numerical simulation of percolation law of 3D porous and fractured double-medium[J]. Rock and Soil Mechanics, 2007, 28（S1）: 291-294.
[6] 王刚，杨鑫祥，张孝强，等.基于DTM阈值分割法的孔裂隙煤岩体瓦斯渗流数值模拟[J].岩石力学与工程学报，2016，35（1）：119-129. WANG Gang, YANG Xinxiang, ZHANG Xiaoqiang, et al. Numerical simulation of gas flow in pores and fissures of coal based on segmentation of DTM threshold[J]. Chinese Journal of Rock Mechanics and Engineering, 2016, 35（1）: 119-129.
[7] 姚艳斌，刘大锰.煤储层孔隙系统发育特征与煤层气可采性研究[J].煤炭科学技术，2006，34（3）：64-68. YAO Yanbin, LIU Dameng. Developing features of fissure system in Henan coal reserves seams and research on mining of coal bed methane[J]. Coal Science and Technology, 2006, 34（3）: 64-68.
[8] 郭旭升，李宇平，刘若冰，等. 四川盆地焦石坝地区龙马溪组页岩微观孔隙结构特征及其控制因素[J].天然气工业，2014，34（6）：9-16. GUO Xusheng, LI Yuping, LIU Ruobing, et al. Characteristics and controlling factors of micro-pore structures of Longmaxi Shale play in the Jiaoshiba area, Sichuan Basin[J]. Natural Gas Industry, 2014, 34（6）: 9-16.
[9] 王刚，沈俊男，褚翔宇，等.基于CT三维重建的高阶煤孔裂隙结构综合表征和分析[J].煤炭学报，2017，42（8）：2074-2080. WANG Gang, SHEN Junnan, CHU Xiangyu, et al. Characterization and analysis of pores and fissures of high-rank coal based on CT three-dimensional reconstruction[J]. Journal of China Coal Society, 2017, 42（8）: 2074-2080.
[10] YAO Yanbin, LIU Dameng, CHE Yao, et al. Petrophysical characterization of coals by low-field nuclear magnetic resonance（NMR）[J]. Fuel, 2010, 89: 1371-1380. [11] ZHAO Yixin, SUN Yingfeng, LIU Shimin, et al. Pore structure characterization of coal by synchrotron radiation nano-CT[J]. Fuel, 2018, 215: 102-110. [12] 滕桂荣，谭云亮，高明.基于Lattice Boltzmann方法对裂隙煤体中瓦斯运移规律的模拟研究[J].岩石力学与工程学报，2007，26（S1）：3503-3508. TENG Guirong, TAN Yunliang, GAO Ming. Simulation of gas seepage in fissured coal based on Lattice boltzmann method[J]. Chinese Journal of Rock Mechanics and Engineering, 2007, 26（S1）: 3503-3508.
[13] Gerami A, Mostaghimi P, Armstrong R T, et al. A microfluidic framework for studying relative permeability in coal[J]. International Journal of Coal Geology, 2016, 159: 183-193. [14] 刘向君，朱洪林，梁利喜.基于微CT技术的砂岩数字岩石物理实验[J].地球物理学报，2014，57（4）：1133. LIU Xiangjun, ZHU Honglin, LIANG Lixi. Digital rock physics of sandstone based on micro CT technology[J]. Chinese Journalof Geophysics, 2014, 57（4）: 1133.
[15] 王刚，江成浩，刘世民，等.基于CT三维重建煤骨架结构模型的渗流过程动态模拟研究[J].煤炭学报，2018，43（5）：1390. WANG Gang, JIANG Chenghao, LIU Shimin, et al. Dynamic simulation of seepage process based on CT 3D reconstruction of coal skeletonstructure model[J]. Journal of China Coal Society, 2018, 43（5）: 1390.
[16] Zhao Y, Sun Y, Liu S, et al. Pore structure characterization of coal by synchrotron radiation nano-CT[J]. Fuel, 2018, 215: 102-110. -
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