煤岩中孔隙与裂隙的结构、形态等特征直接影响煤层气在煤层中的聚集和运移.为对煤岩中孔裂隙类型及孔裂隙的空间分布进行表征,选取宁武盆地中煤阶煤岩,利用微CT 扫描技术对煤岩进行扫描获得CT 图像,运用FDK 算法重建煤岩的灰度图像并基于宏观孔隙度值对灰度图像进行二值化分割,对CT 图像中的微裂纹目标进行了识别;利用CT 扫描获得的图像依据煤岩中基质、孔裂隙及矿物组分均表现出不同的CT 值分布,实现了煤岩中孔裂隙的三维建模,对煤岩中孔裂隙的尺度以及空间分布进行综合表征.研究成果为后期研究煤岩中气体吸附–解吸–渗流的多尺度过程奠定了基础.
The accumulation and migration of coalbed methane in coal seams is affected by the characteristics ofstructure and shape of pores and fractures in coal. To characterize the type and spatial distribution of the pores andfractures in coal, the paper took the medium rank coal from Ningwu basin, used micro-CT scanning technology toscan to get CT images and adopted the FDK algorithm for construction of grayscale images, then based on experimentalporosity, used binary segmentation to cut the grayscale images and recognizing the micro-fractures in CTimage. By using the images obtained by micro-CT scanning technology and based on the coal matrix, pores (fractures)and mineral components showed a different distribution of CT values and finally the 3D modeing of poresand fractures of coal was realized, and the dimension and the spatial distribution of pores and fractures were characterizedcomprehensively. The research results have great contribution to research the process of gas adsorption–desorption and seepage in coal.