海陆过渡相页岩气成藏特征初探:以湘中坳陷二叠系为例  

Preliminary study of the transitional facies shale gas reservoir characteristics:Taking Permian in the Xiangzhong depression as an example

作　　者：包书景[1] 林拓[1] 聂海宽[2] 任收麦[1] 

机构地区：[1]中国地质调查局油气资源调查中心,北京100029 [2]中国石油化工股份有限公司石油勘探开发研究院,北京100083

出　　处：《地学前缘》2016年第1期44-53,共10页Earth Science Frontiers

基　　金：国家自然科学基金项目(41202103)

摘　　要：通过对湘中坳陷邵阳市泉塘村、隆回县北山和邵阳市黄亭等地露头观察及涟源县龙场建新村和涟源县七星街龙潭组、大隆组页岩露头剖面实测、取样和测试分析,重点研究了二叠系页岩龙潭组和大隆组页岩的地化特征、储层特征、含气特征,建立了页岩岩性-岩矿-地化-物性-含气性综合剖面。研究区龙潭组和大隆组页岩干酪根显微组分以壳质组为主,镜质组和惰质组含量较少,有机碳含量大于2%的占样品总数的40%以上,纵向上主要分布在龙潭组上部和大隆组下部,成熟度分布在1.10%~2.22%,平均为1.42%,处在成熟-高成熟阶段。储层微观类型主要有矿物质孔和微裂缝,次要类型为有机质气孔,其中矿物质孔包括残留粒间孔隙、粒间溶蚀孔、粒内溶蚀孔和粒内孔隙。综合分析上二叠统龙潭组-大隆组泥页岩层系厚度、有机碳含量等指标,结合油气显示分析认为,页岩气有利的富集层段为大隆组下部-龙潭组上部厚约80m的优质泥页岩,具备良好的页岩气勘探潜力。值得注意的是,在四川盆地内部的二叠系页岩在地化指标、矿物组成、储层特征和含气量等页岩气成藏条件与湘中地区大致相同,且具有生烃高峰期晚,抬升幅度小等特征,发现了以二叠系泥页岩为源岩的普光等大气田,是海陆过渡相页岩气勘探研究需要注意的地区和领域。Through observation（Quantang Shaoyang,Beishan Longhui County）,measured profile（Jianxincun Lianyuan County and Qixingjie Lianyuan County）,sampling and laboratory analysis such as adsorbed gas content,geochemical parameters and reservoir parameters etc.of Longtan Dalong Formations of Permian in the Xiangzhong depression,we established a composite section of lithology-rock mineral-geochemical-physical properties-gas-bearing properties of Longtan Dalong Formations of Permian.The kerogen maceral of the Dalong Formation and Longtan Formation was mainly exinite,vitrinite and inertinite content is less.Samples with total organic carbon greater than 2% accounted for more than 40% of the total longitudinal samples,mainly distributed in the bottom of Dalong Formation and the top of Longtan Formation.The thermal maturity is between 1.10%-2.22%,with an average of 1.42% and is at mature to high mature stage.The microreservoir types are mainly mineral micro-pores and micro-fracture,followed by organic matter micro-pore.The mineral micro-pores mainly include interparticle residual micro-pores,interparticle dissolution micro-pores,intraparticle dissolution micro-pores and intraparticle micro-pores.Parameters such as thickness of the shale,total organic content,maturity and gas content,oil gas showing,indicated that the most favorable member for shale gas accumulations is the bottom of the top of Longtan and Dalong Formations with about 80 m thickness which may have good shale gas exploration potential.It is worth noting that shale gas accumulation conditions such as geochemical parameters,mineral composition,reservoir parameters and gas content etc.of the Permian shale in the Sichuan Basin is similar to those in the Xiangzhong depression.They have late peak period of hydrocarbon generation and shallow uplift.The giant Puguang gas field is sourced from the Permian shale.It is needed to pay attention to the transitional facies of shale gas exploration and research of the Permian shale in Sichuan Basin.

关 键 词：页岩气 海陆过渡相 二叠系 湘中坳陷 

分 类 号：P618.130.21[天文地球—矿床学]