深部煤储层孔隙–裂缝结构对深部煤层气资源潜力评价和勘探开发具有重要意义。选取鄂尔多斯盆地东缘大宁–吉县区块DJ57井本溪组5个煤岩样品为研究对象，在煤岩煤质参数测试的基础上，采用气体吸附法、高压压汞法和微米CT扫描等测试手段，对深部煤储层中的纳米级孔隙−微米级裂缝进行多尺度定量表征，综合评价不同尺度的孔裂隙结构特征。再结合渗透率和甲烷等温吸附试验，探讨了微观孔裂隙对深部煤储层中煤层气的赋存和渗流的影响。研究结果表明：基于多种孔隙表征方法对深部煤储层孔裂隙进行多尺度定量表征，其孔裂隙体积分布类型主要以“U”型为主，呈现出微孔与微裂缝并存双峰态，主要集中在0.3～1.5 nm和>100 μm的范围内。其中，微孔(<2 nm)、介孔(2～50 nm)、宏孔(50 nm～10 μm)和微裂缝(>10 μm)体积平均分别占总孔裂隙体积的80.18%，6.70%，1.65%和11.47%。随着微孔发育而吸附气量呈增大的趋势，微孔可以提供大量吸附点位，为深部煤层气的吸附和赋存提供场所。随着微裂缝发育而游离气量呈增大的趋势，微裂缝可以提供大量储集空间，为深部煤层气的富集提供空间条件。此外，微裂缝在三维空间中相互连通，形成网状结构，连通性强。随着微裂缝越发育，煤储层渗透率越大，微裂缝增强了煤层气的渗流能力。纳米级孔隙和微米级裂隙发育特征分别控制着深部煤层气吸附能力和开发潜力。

The pore-fracture structure of deep coal reservoir is of great significance to the evaluation and exploration of deep coalbed methane resource potential. this work takes the 5 coal and rock samples from the DJ57 Benxi Formation in Daning-Jixian Block, east margin of Ordos Basin are selected as the research object. On the basis of coal rock and coal quality parameter testing, gas adsorption method, high pressure mercury injection method and micron CT scanning and other testing methods are adopted to conduct full-scale quantitative characterization of nano-scale pore and micron scale cracks in the pore and fissure structure of coal reservoir, and comprehensively evaluate the pore and fissure structure characteristics of different scales. Combined with permeability and methane isothermal adsorption experiments, the influence of micro-porosity and fissure on the occurrence and migration of coalbed methane in deep coal reservoirs was discussed. The results show that the multi-scale quantitative characterization of deep coal reservoir pores and fractures is based on a variety of pore characterization methods, and the pore and fracture volume distribution type is mainly U-shaped, showing a bimodal coexistence of micro-pores and micro-fractures, mainly concentrated in in 0.3-1.5 nm and > 100 μm. Among them, micropores (<2 nm), mesoporous (2−50 nm), macroporous (50 nm−10 μm) and microfractures (>10 μm) accounted for 80.18%,6.70%,1.65% and 11.47% of the total pore crack volume, respectively. With the development of micropores, the adsorbed gas tends to increase, and micropores can provide a large number of adsorption sites for deep coalbed methane adsorption and occurrence. With the development of micro-fractures, the free gas volume tends to increase. Micro-fractures can provide a large amount of storage space and provide space conditions for deep coalbed methane enrichment. In addition, microcracks are interconnected in three-dimensional space, forming a network structure with strong connectivity. With the development of micro-fractures, the permeability of coal reservoir increases, and micro-fractures enhance the seepage capacity of coalbed methane. The adsorption capacity and development potential of deep coalbed methane are controlled by the development characteristics of nano-scale pores and micro-scale fractures respectively.