摘要
柳林地区石炭—二叠系煤层顶板流体包裹体包括盐水、液态烃、气液烃和气态烃4种类型,主要分布于砂岩石英加大边、石英微裂隙和灰岩粒屑重结晶方解石、裂隙溶孔充填方解石中。根据包裹体热力学特征,可将山西组流体类型划分为低温低盐流体和高温高盐流体,太原组划分为低温混盐和高温高盐流体。太原组流体类型反映了海陆交互相沉积环境和后期地表淡水沟通的叠加影响。根据包裹体的类型、荧光特征和热力学特征,结合盆地热演化史分析结果,表明第一期烃类注入发生在中-晚三叠世,烃类产量较少;第二期烃类注入发生在早白垩世,气态烃包裹体数量多,生烃强度大,是本区主要的生烃阶段。
Four types of fluid inclusions occur in the coal seam roof in the Liulin area including the brine liquid hydrocarbon, liquid-gas hydrocarbon and gas hydrocarbon. They are mainly trapped either in the quartz overgrowth and fracture of sandstone or in recrystallized calcites and solution holes filled calcites of limestone. Based on the thermodynamic of fluid inclusions, the fluid inclusions in the Shanxi Formation were classified as types of low-temperature and low salinity and of high-temperature and high salinity, while those in the Taiyuan Formation were defined as types of low-temperature and composite-salinity and of high-temperature and high salinity fluids. Types of the fluid inclusions in the Taiyuan Formation testified the superimposed impact of the paralic coal-forming environment to the connectivity with surface freshwater in the later period. It was suggested that, according to the fluid inclusions types, micro-fluorescence and thermodynamic characters of the fluid inclusions and in combination with the geothermal evolution analysis, the first stage of the hydrocarbon injection in the Liulin area occurred during Middle to Late Triassic with relatively low amount of hydrocarbon generation. The second stage which was a major period of the hydrocarbon generation occurred during Early Cretaceous with prolific gas inclusions and high hydrocarbon generation intensity.
出处
《高校地质学报》
CAS
CSCD
北大核心
2012年第3期419-426,共8页
Geological Journal of China Universities
基金
国家科技重大专项课题(2011ZX05062-01, 2011ZX05034-01)资助
关键词
流体包裹体
煤成烃
热演化史
柳林
鄂尔多斯盆地
Fluid inclusion
coal-derived hydrocarbon
paleo-geothermal history
Liulin
Ordos Basin
