【摘要】：綜合運用有機超顯微組分識別、聚焦離子束掃描電鏡、高溫高壓等溫吸附和頁巖氣稀有氣體同位素年齡測定等技術,深入研究四川盆地涪陵地區(qū)頁巖氣主力產(chǎn)層上奧陶統(tǒng)五峰組—下志留統(tǒng)龍馬溪組的烴源品質(zhì)、有機質(zhì)孔隙發(fā)育特征、頁巖氣賦存形式和封存機制。結(jié)果表明:1五峰組—龍馬溪組富有機質(zhì)頁巖主要形成于表層水生產(chǎn)力高、底層水缺氧的沉積環(huán)境,TOC值呈兩段式分布,下段TOC≥3%,主要由浮游藻類、疑源類、細菌和筆石等成烴生物及殘留瀝青組成,其中筆石是TOC值的主要貢獻者之一,但頁巖氣主要來自浮游藻類、疑源類等富氫富脂質(zhì)有機質(zhì)及由其生成的液態(tài)烴裂解。2有機質(zhì)孔隙主要發(fā)育在固體瀝青和富氫有機質(zhì)中,是頁巖氣的主要儲集空間。筆石等大量有機質(zhì)呈紋層狀、堆積式分布,為頁巖氣提供了更多的儲存空間和各類孔隙連通、流體流動的優(yōu)勢通道。3涪陵頁巖氣處于超臨界狀態(tài),以游離氣為主。頁巖氣封閉體系的形成時間與生氣高峰期之間的有效匹配,以及后期構(gòu)造活動對頁巖氣封存條件的改造程度低是復雜構(gòu)造區(qū)高熱演化頁巖氣滯留富集的關鍵,頁巖的吸附作用、毛管封閉以及低速擴散形成了頁巖氣微觀滯留富集機制�？梢�,復雜構(gòu)造區(qū)高熱演化海相頁巖氣的形成與富集受缺氧的沉積環(huán)境、優(yōu)質(zhì)的烴源品質(zhì)、優(yōu)越的儲集空間和良好的封存條件綜合控制。
[Abstract]:The hydrocarbon source quality, pore development characteristics, shale gas occurrence form and storage mechanism of Upper Ordovician Wufeng formation and Lower Silurian Longmaxi formation in Fuling area, Sichuan Basin, were studied by means of organic ultrastructure identification, focused ion beam scanning electron microscope, high temperature and high pressure isotherm adsorption and rare gas isotopic dating of shale gas. The results show that: (1) the organic shale of Wufeng formation-Longmaxi formation is mainly formed in the sedimentary environment with high surface water productivity and anoxia in the bottom water. TC value is two-stage distribution, and the lower segment TOC 鈮，

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