煤系页岩纳米孔隙结构特征和演化及其对页岩气赋存的影响

Shale gas in coal measures is an important type of shale gas. The structure and evolution of nanopore in shale and their influences on occurrence of shale gas in coal measures are no literature reported at present. Take the different shale samples in coal measures in Sichuan and Ordos basins for research, the development, morphology, classification and quantitative characterization of nanopores in shales of coal measures are systemically studied, by using field emission SEM，nanometer CT scanning, high-pressure mercury injection, low-temperature liquid nitrogen absorption, carbon dioxide absorption, high-pressure gas isotherm adsorption, gold tube thermal simulation experiment, et al. The differences of occurrence characteristics and structure of nanopores are compared from shales of different total organic carbon and different maturity in coal measures. The evolution model of porosity and nanopore of shale in coal measures is established. The main control factor of nanopore development in shale of coal measures is also studied. The relationship between nanopore structure of shale and storage ability of shale gas in coal measures is investigated. The occurrence mechanism of shale gas in coal measures is then discussed. The research results can be applied to the effective evaluation for shale gas reservoir in coal measures, and it is of important significance for the resource potential assessment and the recoverability evaluation of shale gas in coal measures.

煤系页岩气是页岩气的重要类型，针对煤系页岩纳米孔隙结构和演化及其对煤系页岩气赋存的影响，目前未见文献报导。本研究拟选取四川与鄂尔多斯盆地不同煤系地层泥页岩样品，采用场发射扫描电镜、纳米CT扫描、高压压汞、低温液氮和二氧化碳吸附、高压气体等温吸附、黄金管热模拟实验等多种分析方法，系统研究不同煤系页岩中纳米孔隙的发育情况、形貌特征、类型划分与定量表征，对比研究不同有机碳、不同成熟度的煤系页岩中纳米孔隙特征和结构的差异，建立煤系页岩孔隙度和纳米孔隙的演化模式，研究煤系页岩纳米孔隙发育的主控因素及其与页岩气储集的关系，探讨煤系页岩气的赋存机理。本项研究成果可以应用于煤系页岩气储层的有效评价，对我国煤系地层页岩气资源潜力评估和可采性评价具有重要的意义。

煤系页岩气是页岩气的重要类型。煤系页岩纳米孔隙结构特征和演化会影响页岩气的赋存富集。本项研究以四川、鄂尔多斯等盆地煤系页岩样品为研究对象，采用场发射扫描电镜、高压压汞、低温液氮和二氧化碳吸附、黄金管热模拟实验等多种分析方法，系统研究了煤系页岩中纳米孔隙的发育情况、形貌特征、类型划分与定量表征，对比了不同有机碳、不同成熟度的煤系页岩中纳米孔隙特征和结构的差异，建立了煤系页岩孔隙度和纳米孔隙的演化模式，分析了煤系页岩纳米孔隙发育的主控因素及其与页岩气储集的关系，探讨了煤系页岩气的赋存机理。本项研究成果可以应用于煤系页岩储集空间的表征、煤系页岩气储层的有效评价与优选，为我国煤系地层页岩气资源潜力分析和可采性评价提供科学依据。