
科学技术与工程

中国技术经济学会
基于微CT扫描的砂砾岩孔隙结构表征
Characterization of Pore Structure of Sand and Conglomerate Based on Micro-CT Scanning
针对砂砾岩渗透性差、颗粒大小混杂、孔隙结构复杂的特点,利用CT(computed tomography)扫描及三维重构技术对玛湖乌尔禾组砂砾岩的孔隙结构特征及连通性展开研究,通过建立结合常规阈值分割与顶帽算法的孔隙结构提取方法,解决了微裂缝难以提取的难题。研究发现,乌尔禾组砂砾岩主要以粒间孔隙、溶蚀孔隙和微裂缝为主,三维结构以片状和孤立结构为主。砂砾岩样品等效半径小于30 μm的孔隙虽然占比较高,但其对总孔隙体积的贡献却相对较低,而大于60 μm的孔隙虽然较少,但其占据着总孔隙体积50%以上,为主要储集空间。实验样品以Ⅲ级连通域为主,有较好的连通性,有利于油气的聚集和开采。强非均质砂砾岩孔隙结构特征的研究对深入了解砂砾岩孔隙结构特征、寻找和开发砂砾岩油气藏有重要的理论和实践价值。
Considering the characteristics of poor permeability, mixed particle sizes, and complex pore structures of conglomerates, a study was conducted on the pore structure characteristics and connectivity of the Mahu Urho Formation conglomerates using CT(computed tomography) scanning and 3D reconstruction techniques. By establishing a pore structure extraction method combining conventional threshold segmentation and top-hat algorithm, the challenge of extracting microcracks was overcome. The study reveals that the main types of pores in the Urho Group conglomerates are intergranular pores, dissolved pores, and microfractures, with the 3D pore types are mainly lamellar pore structures and isolated pore structures. Although pores with equivalent radii of conglomerate samples smaller than 30 μm account for a high proportion, their contribution to the total pore volume is relatively low. Pores larger than 60 μm, while fewer in number, occupy over 50% of the total pore volume, serving as the primary storage space. Experimental samples are predominantly characterized by level III connected domains, exhibiting good connectivity conducive to the accumulation and extraction of oil and gas. The investigation into the pore structure characteristics of strongly inhomogeneous conglomerates holds significant theoretical and practical value for an in-depth understanding of such characteristics and for the exploration and development of oil and gas reservoirs in sand conglomerates.
微CT / 砂砾岩 / 乌尔禾组 / 微裂缝提取 / 孔隙结构 / 连通性
micro-CT scanning / sandy conglomerate / Urho Formation / extraction of microcracks / pore structure / pore connectivity
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