The pore characteristics of coal reservoirs play a very important role in the migration of coalbed methane reservoirs, and its heterogeneity has been studied by a large number of scholars. However, there are few studies on lignite reservoirs. In this paper, three sets of lignite reservoirs in the Jiergalangtu depression are taken as the research object. The scanning electron microscope (SEM) images are converted from time-domain signals to frequency-domain signals through Fourier transformation, which quantitatively characterizes the heterogeneity of coal reservoirs. The variance of the value indicates that the three sets of coal seams NO.4Var<NO.5Var<NO.6Var. Through nitrogen adsorption experiment and fractal analysis, the pore continuity, surface roughness, pore structure, pore type and other aspects are studied. The lignite in the study area has high pore surface roughness and complex pore structure. Affected by various geological factors such as material composition, coal-forming environment, degree of evolution and other geological factors, lignite reservoirs in different layers and different mining areas show obvious heterogeneity.

中文翻译：

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内蒙古二连盆地褐煤储层孔隙特征及其非均质性

煤储层的孔隙特征在煤层气储层运移中起着非常重要的作用，其非均质性已被大量学者研究。然而，关于褐煤储层的研究很少。本文以吉尔嘎朗图凹陷三套褐煤储层为研究对象。扫描电子显微镜（SEM）图像通过傅里叶变换从时域信号转换为频域信号，定量表征煤储层的非均质性。该值的方差表明三组煤层NO.4Var<NO.5Var<NO.6Var。通过氮吸附实验和分形分析，对孔隙连续性、表面粗糙度、孔隙结构、孔隙类型等方面进行了研究。研究区褐煤孔隙表面粗糙度高，孔隙结构复杂。受物质组成、成煤环境、演化程度等地质因素等多种地质因素的影响，不同层位、不同矿区的褐煤储层呈现出明显的非均质性。