【摘要】：湘西北地區(qū)廣泛發(fā)育新元古界震旦系陡山沱組暗色泥頁巖,已有鉆井中氣顯示活躍,揭示出該地區(qū)較好的頁巖氣勘探潛力。在觀察野外地質(zhì)露頭的基礎(chǔ)上,通過地球化學(xué)分析、掃描電鏡、X射線衍射、低溫氮?dú)馕健⒌葴匚降确治鰷y試,對陡山沱組泥頁巖的發(fā)育及分布規(guī)律、有機(jī)地球化學(xué)特征、儲層特征及吸附性能等頁巖氣成藏條件進(jìn)行了綜合研究,并優(yōu)選了有利區(qū)帶。結(jié)果表明:湘西北地區(qū)陡山沱組暗色泥頁巖分布變化大,僅在大庸向斜地區(qū)沉積厚度較大,為20~50 m,有機(jī)碳質(zhì)量分?jǐn)?shù)為0.5%~3.0%,有機(jī)質(zhì)類型以Ⅰ型為主,有機(jī)質(zhì)成熟度為3.0%~4.0%,達(dá)到過成熟演化階段,具備較為有利的生氣條件;泥頁巖儲層礦物成分以脆性礦物為主,質(zhì)量分?jǐn)?shù)為21%~78.7%,發(fā)育多種類型孔隙空間,比表面積和孔體積均較高,多個(gè)泥頁巖樣品等溫吸附實(shí)驗(yàn)統(tǒng)計(jì)顯示,甲烷最大吸附質(zhì)量體積為0.80~1.77 m3/t,泥頁巖儲層具有較好的儲集條件及吸附性能。湘西北大庸向斜地區(qū)構(gòu)造條件相對穩(wěn)定,保存條件較好,具有有利的頁巖氣成藏條件,可作為陡山沱組頁巖氣勘探的有利區(qū)帶。
[Abstract]:The dark mud shale of the Doushantuo formation of the Neoproterozoic Sinian is widely developed in the northwest of Hunan Province, and the gas is active in drilling, which reveals the potential of shale gas exploration in this area. On the basis of field geological outcrop observation, through geochemical analysis, scanning electron microscope X-ray diffraction, low temperature nitrogen adsorption, isothermal adsorption and so on, the development and distribution law and organic geochemical characteristics of mudstone shale in Doushantuo formation were studied. The reservoir characteristics and adsorption properties of shale gas reservoir forming conditions were studied, and favorable zones were selected. The results show that the distribution of dark mudstone shale in Doushantuo formation in northwestern Hunan has a great change, only in the Dayong syncline, the sedimentary thickness is 20 ~ 50 m, the organic carbon mass fraction is 0.5 ~ 3.0%, and the type of organic matter is mainly type 鈪，

本文編號：2207749