海相油气地质2018，Vol.23Issue(2)：70-76,7.DOI:10.3969/j.issn.1672-9854.2018.02.009
湘西北地区下志留统龙马溪组页岩矿物成分特征及意义
Characteristics and Significance of Mineral Compositions of Shale in Lower Silurian Longmaxi Formation, Northwestern Hu'nan
摘要
Abstract
Using X-ray diffraction (XRD) and scanning electron microscopy (SEM) techniques, the qualitative and quantitative analyses of the mineral composition of shale in the Lower Silurian Longmaxi Formation in northwestern Hu'nan were conducted. The main mineral components of the shale are quartz (48.1％), clay minerals (34.0％), and feldspar (11.5％), containing small amounts of calcite, dolomite, and pyrite. The content of illite and illite/montmorillonite mixed layer in clay minerals is relatively high, averaging 64.7％ and 21.7％ respectively. The clay mineral is the combination of illite, ordered illite/montmorillonite, and a small amount of chlorite and trace kaolinite, reflecting that the Longmaxi Formation shale reached the stage of late diagenesis. In a transitional sedimentary environment from shallow-water to deep-water continental shelf, the shale organic matter of Longmaxi Formation is easy to be enriched and preserved. The content of brit le minerals in shale core samples ranged from 34.4％ to 79.6％, and the average brittleness index reached 65.4％, showing a good condition for fracturing transformation. Compared with the surrounding Jiaoshiba shale gas field, the composition of the shales in the Longmaxi Formation is similar, reflecting the geological potential of shale gas in northwestern Hu'nan.关键词
湘西北/志留纪/龙马溪组/页岩气/矿物成分Key words
Silurian/Longmaxi Formation/Shale gas/Mineral composition/Northwestern Hu'nan分类
能源科技引用本文复制引用
刘亢,曹代勇,林中月,王玉芳..湘西北地区下志留统龙马溪组页岩矿物成分特征及意义[J].海相油气地质,2018,23(2):70-76,7.基金项目
本文受中国地质调查局项目"页岩气有利区块调查与优选评价"(编号:12120114054101)资助 （编号:12120114054101）
