湘中涟源凹陷二叠系小江边组页岩气地质条件  

Geological conditions of shale gas in Permian Xiaojiangbian Formation, Lianyuan sag, central Hunan

作　　者：田巍 苗凤彬[1] 陈林 王强[1] 白云山[1] TIAN Wei;MIAO Feng-bin;CHEN Lin;WANG Qiang;BAI Yun-shan(Wuhan Center of China Geological Survey, Wuhan 430205 , China)

机构地区：[1]中国地质调查局武汉地质调查中心

出　　处：《桂林理工大学学报》2019年第3期575-581,共7页Journal of Guilin University of Technology

基　　金：十三五国家科技重大专项(2016ZX05034001-002);中国地质调查局地质调查项目(DD20160179)

摘　　要：以湘中地区涟源凹陷二叠系小江边组富有机质泥页岩为研究对象,通过有机地球化学分析测试、X射线衍射矿物分析、扫描电镜观察、压汞实验、氮气吸附测试等实验方法,联合表征泥页岩的储层特征和储集空间特征;结合等温吸附实验,探讨了小江边组页岩的含气性特征。结果表明:小江边组有效泥页岩累计厚度12.46~49.89 m;有机碳含量一般大于1%,平均1.48%;有机质类型主要为Ⅰ型,有机质成熟度在1.61%~2.31%,属于高成熟-过成熟富有机质泥页岩;微孔裂隙发育,孔隙结构以中孔为主,孔隙间连通性较好;泥页岩吸附含气量为0.37~0.78 cm^3/g,具有页岩气成藏的基本地质条件。基于泥页岩有效厚度、有机质含量及类型、热演化程度和含气量等因素,预测涟源凹陷小江边组页岩气有利勘探区主要位于车田江向斜北部、桥头河向斜北部以及恩口-斗笠山向斜北部等区域。Based on organic geochemical test, X-ray diffraction mineral analysis, electron microscopy scanning, mercury injection experiment, and nitrogen adsorption tests, combined with methane isothermal adsorption, the characteristics of reservoir space and gas content of Permian Xiaojiangbian Formation shale in Lianyuan sag, were discussed. It is shown that the shale reservoir of Xiaojiangbian Formation is 12.46-49.89 m thick. Organic carbon content is generally greater than 1%, with an average of 1.48%. Organic matter type is mainly typeⅠ, the maturity of organic matter ranges from 1.61% to 2.31%. The micropores are well developed. The pore structure is mainly mesoporous, pore connectivity is good. Shale gas adsorption contents range from 0.37-0.78 cm^3/g. These indicate that Xiaojiangbian Formation has essential conditions for the shale-gas reservoir formation. Based on the effective thickness of shales, organic matter content and type, degree of thermal evolution, gas content, favorable prospect areas of Xiaojiangbian Formation shale gas should be mainly located in the north of Chetianjiang syncline, Qiaotouhe syncline and Enkou-Doulishan syncline in Lianyuan sag.

关 键 词：页岩气 沉积地层特征 储层特征 小江边组 涟源凹陷 

分 类 号：P618.13[天文地球—矿床学]