摘要
页岩的微观孔隙是评价页岩气资源潜力以及是否具有开采价值的重要指标。对上扬子区遵义、通江、广元等地下寒武统牛蹄塘组、下志留统龙马溪组和上二叠统大隆组的页岩进行采样，运用扫描电镜、氮气吸附和压汞实验对这些页岩的孔隙结构特征及其影响因素进行了研究。结果表明，大隆组页岩具有很低的比表面积和孔隙度，其中孔径小于100mm的孔对孔隙度的贡献率在10％左右，主要孔隙类型为草莓体黄铁矿晶间孔：龙马溪组和牛蹄塘组页岩则具有较高的比表面积和孔隙度，50％～80％以上的孔隙度来自小于100mm的贡献，主要孔隙类型是干酪根孔隙和溶蚀孔隙。认为页岩微观孔隙的发育与页岩的类型、溶蚀作用以及成熟度等因素有关。
Microscopic pore structures of shale are important to evaluating shale gas potential and exploitation value. Scanning electron microscopy（SEM）, nitrogen sorption and mercury intrusion experiments were carried out to study microscopic pore structures and the controlling factors of Paleozoic shales in Upper Yangtze region, including Zunyi in Guizhou province and Tongjiang and Guanyuan in Sichuan province. The results show that the Upper Permian Dalong shale has low values of specific surface area and porosity, in which 10% of porosity is contributed by the pores below 100nm, and the framboid pyrite intercrystal pore is common in pore type. The Lower Silurian Longmaxi and Lower Cambrian Niutitang shales have higher specific surface and porosity than Dalong shale, in which 50%-80% of porosity is contributed by the pores less than 100nm, and kerogen pores and dissolution pores are dominant in pore type meanwhile a small amount of honeycomb pores, dissolution impressions and microfractures as well. It is demonstrated that microscopic pore structures are determined by type, dissolution and maturity of shale.
出处
《海相油气地质》
CSCD
北大核心
2015年第1期71-78,共8页
Marine Origin Petroleum Geology
基金
国家973项目04课题"深层页岩气储集物性及含气性研究"(编号:2012CB214704)
国家油气重大专项课题"深层高成熟烃源岩的容烃与排烃评价"(编号:2011ZX05008-002-20)
国家自然科学基金"我国南方古生界高过成熟页岩吸附特征与页岩含气性评价"(编号:41273058)资助
关键词
上扬子区
古生界
页岩气
孔隙结构
孔隙度
Paleozoic
Shale gas
Pore structure
Porosity
Upper Yangtze region
