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我国不同地区页岩非均质性研究是亟待解决的基础地质问题,且四川盆地陆相页岩气的研究十分薄弱.通过对鄂西-渝东地区下侏罗统自流井组东岳庙段剖面和钻井岩心的岩石学特征、地球化学等方面的精细分析,结合测井曲线,查明了该层段地球化学垂向变化特征及有机质富集模式.结果表明,东岳庙段脆性矿物含量高,粘土矿物含量较少,下部有机质含量高于上部.地球化学指标所反映的古气候、古生产力、古氧化还原、古盐度表明东岳庙段垂向上具有明显差异;东岳庙段下部为干旱炎热古气候、贫氧-偏咸化水体和高古生产力,而东岳庙段上部为温暖湿润古气候、淡化水体和低古生产力,故东岳庙段下部更有利于有机质富集.
The study of shale heterogeneity in different areas of China is the basic geological problem to be solved urgently, and the study of terrestrial shale gas in Sichuan Basin is very weak.Through the study on the section of Dongyuemiao section of the Lower Jurassic Ziliujing Formation in western Hubei and eastern Chongqing, The petrological characteristics and geochemical characteristics of drilling cores, fine geochemical analysis and log data show that the geochemical vertical variation and organic matter enrichment pattern of this layer have been identified.The results show that the content of brittle minerals in Dongyuemiao section is higher than that of clay The content of organic matter in the lower part is higher than that in the upper part.The paleoclimate, paleoproductivity, paleo-oxidation reduction and paleosalinity reflected by the geochemical indicators show that the Dongyuemiao section is obviously different in the vertical direction and the lower part of the Dongyuemiao section is the arid and hot paleo-climate , Oxygen-poorly-salty water body and high palaeo-productivity, while the upper part of Dongyuemiao section is warm and humid paleoclimate, desalinating water body and low paleoproductivity, so the lower part of Dongyuemiao section is more conducive to the enrichment of organic matter.