中扬子鄂西地区海相页岩气地质特征及找矿成果综述  

Geological Characteristics and Prospecting Results of Marine Shale Gas of Western Hubei,Middle Yangtze

作　　者：许露露 文剑航 温雅茹 王亿 张焱林 谢通 任志军 罗凡 胡江龙 Xu Lulu;Wen Jianhang;Wen Yaru;Wang Yi;Zhang Yanlin;Xie Tong;Ren Zhijun;Luo Fan;Hu Longjiang(Hubei Geological Survey,Wuhan,Hubei 430034)

机构地区：[1]湖北省地质调查院,湖北武汉430034

出　　处：《资源环境与工程》2021年第5期611-624,共14页Resources Environment & Engineering

基　　金：湖北省自然科学基金项目“鄂西地区五峰—龙马溪组页岩孔缝特征对页岩气保存条件的指示”(2020CFB501);湖北省自然资源厅科研项目“鄂西地区下古生界页岩气储层物性特征及差异富气机理研究”(ZRZY2020KJ10);湖北省地质局科研项目“鄂西地区主要含气层系页岩气形成、富集与保存条件研究”(KJ2020—4);湖北省自然资源厅地调项目“湖北利川柏杨坝—团堡地区页岩气远景区调查”(DTCG—190409)。

摘　　要：针对鄂西地区海相页岩主要含气层系地质特征及找矿成果阐述不充分的现状,利用钻井及野外地层剖面资料,对该区4套主要含气页岩层系的地层及沉积相、有机地球化学及含气性特征进行综合对比分析,并对页岩气富集规律进行总结。研究表明,陡山沱组二段(简称“陡二段”)和大隆组为台盆相沉积,发育黑色页岩—碳酸盐岩组合;牛蹄塘组一段(简称“牛一段”)和五峰组—龙马溪组为深水陆棚相沉积,主要发育黑色含硅炭质页岩。大隆组埋深相对偏浅;陡二段和牛一段富有机质页岩相对较厚;大隆组TOC相对最高,陡二段最低。含气性特征表明,纵向上牛一段和大隆组具有更高的含气量,陡二段相对最低。平面上五峰组—龙马溪组和大隆组页岩含气层分布面积较广,陡二段和牛一段仅局限分布在黄陵背斜南翼。4套地层页岩气富集均受到沉积相带的控制,且构造样式为页岩气保存的关键,单斜型和宽缓向斜型构造样式有利于页岩富集保存。与陡二段和牛一段相比,五峰组—龙马溪组深水陆棚相和大隆组台盆相分布面积广阔,TOC含量高,热演化程度适中,顶底板封闭性更好,具备良好的页岩气成藏潜力。大隆组页岩将成为未来几年鄂西页岩气勘探开发的重点层位,继续研究大隆组岩相古地理分布特征、探寻台地和台盆相的地理边界、进行有利区优选和资源量计算是未来几年的研究重点。In view of the insufficient research of the geological characteristics and prospecting results of the main gas-bearing strata of marine shale in western Hubei,the data of drilling wells and field profile was used to comprehensively analyze the stratigraphic and sedimentaryfacies,organic geochemistry,gas-bearing characteristics,and the shale gas enrichment mechanism of the 4 main gas-bearing shale series in the area.The study shows that the source rocks of the second member of Doushantuo Formation(hereinafter referred to as“Dou2”)and Dalong Formation are platform basin facies deposits,and the black shale-carbonate lithologic association is developed.The first member of Niutitang Formation(hereinafter referred to“Niutitang Formation”)and Wufeng-Longmaxi Formation are deep shelf facies deposits,mainly black siliceous shale.The buried depth of Dalong Formation is relatively shallow,the organic-rich shales of Dou 2 and Niu 1 are relatively thick,the TOC of Dalong Formation is relatively high,and Dou 2 is the lowest.The gas content characteristics showed that the gas content of Niu 1 and Dalong groups is higher vertically,and that of Dou 2 is the lowest.On the plane,the shale gas-bearing layers of Wufeng Formation-Longmaxi Formation and Dalong Formation are widely distributed,and the Dou 2 and Niu 1 members are only limited to the south wing of Huangling anticline.The enrichment of shale gas in the four sets of strata is controlled by sedimentary facies,and the structural style is the key to the preservation of shale gas.The monoclinic and wide gentle syncline structural styles are beneficial to the enrichment and preservation of shale gas.Compared with Dou 2 and Niu 1 Members,Wufeng Formation-Longmaxi Formation deepwater shelf facies and Dalong Formation platform basin facies have wide distribution area,high TOC content,moderate thermal evolution degree,better sealing of roof and floor,and good shale gas accumulation potential.In particular,the Dalong Formation shale will become the key horizon for shale gas e

关 键 词：页岩气 沉积相 含气性 富集机理 鄂西 

分 类 号：TE122.1[石油与天然气工程—油气勘探]