渝东北下寒武统牛蹄塘组页岩微纳米孔隙结构特征

发布时间：2018-04-22 08:37

本文选题：渝东北 + 下寒武统　；参考：《地球科学》2017年07期

【摘要】：中国南方下寒武统牛蹄塘组页岩是目前页岩气勘探的主要目的层位之一,然而在渝东北地区其勘探效果不尽如人意,原因在于其孔隙结构特征并未清楚.采用聚焦离子束扫描电子显微镜、纳米CT和气体吸附实验等方法对渝东北地区下寒武统牛蹄塘组页岩微纳米孔隙结构进行了定量表征.结果表明,牛蹄塘组页岩的微纳米孔隙类型主要为无机质孔隙,包括粒间孔和粒内孔,而N2吸附滞后环类型属于H4型,对应孔隙类型为单边狭缝型孔隙;牛蹄塘组页岩的平均总孔体积为0.031 7mL/g,平均总比表面积为34.57m~2/g.牛蹄塘组页岩过高的演化程度导致有机质孔隙不发育,进而导致其微纳米孔隙具有较差的连通性;中孔贡献了绝大部分的孔体积,而微孔则贡献了相对较多的比表面积.
[Abstract]:The Lower Cambrian Niutetang formation shale is one of the main target layers for shale gas exploration in southern China. However, the exploration results in northeast Chongqing are not satisfactory, because the pore structure characteristics are not clear. Focused ion beam scanning electron microscopy, nano-CT and gas adsorption experiments were used to quantitatively characterize the micropore structure of the Lower Cambrian Niutetang formation shale in the northeast of Chongqing. The results show that the micropore type of Niulitang formation shale is mainly inorganic pore, including intergranular pore and intragranular pore, while N2 adsorption hysteresis ring type belongs to H4 type, corresponding pore type is one-sided slit pore. The average total pore volume of Niulitang formation shale is 0.031 mL / g, and the average total specific surface area is 34.57 mg / g. The high evolution degree of Niulitang shale leads to the undeveloped pores of organic matter, which leads to the poor connectivity of micropores, while the mesopore contributes to most of the pore volume, while the micropore contributes to a relatively large specific surface area.
【作者单位】：中国石油大学油气资源与探测国家重点实验室;中国石油大学非常规天然气研究院;
【基金】：国家自然科学基金项目(No.41472112) 国土资源部南方页岩气基础地质调查工程项目(No.12120114046701)
【分类号】：P618.13

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