柴达木盆地北缘侏罗系层序地层与沉积相研究

依据钻井、露头的生物地层研究成果 ,特别是以冷科 1井的生物地层标定为基础 ,应用层序地层学理论对柴北缘覆盖区侏罗系进行了地震地层的追踪对比与地震相、沉积相研究 ,并探讨了层序格架内烃源岩、储层的发育特征。其结果表明 ,柴北缘侏罗系可划分为 5个层序、11个体系域。其中 ,下侏罗统可划分为两个层序 ,沉积相均以扇三角洲与半深湖—深湖相为特征 ;中侏罗统为一个层序 ,沉积相主体为河流、沼泽相 ,仅该层序顶部发育浅湖—半深湖相 ;上侏罗统为两个层序 ,沉积相以氧化宽浅湖、三角洲、河流为特征。烃源岩发育于中下侏罗统中。而侏罗系砂体分布广泛 ,可构成天然气的优质储层 ,部分可构成原油的良好储层

STUDY OF JURASSIC STRATIGRAPHIC SEQUENCE AND SEDIMENTARY FACIES IN NORTH OF QAIDAM BASIN

From biostratigraphic classification of drill and outcrop, specially like Lengke 1 well, and based on theory of stratigraphic sequence, the authors trace and identify seismic formation of the Jurassic stratum in North of Qaidam Basin, research seismic facies and sedimentary facies of Jurassic stratum and discuss the characteristics of hydrocarbon source rocks and reservoirs in stratigraphic framework. The stratum results show that the Jurassic stratum can be divided into 5 sequences and 11 system tracts. The Lower Jurassic consists of 2 sequences which include fan delta, semi deep lake and deep lake facies. The Middle Jurassic consists of 1 sequence which includes mainly fluvial facies and paludal facies. The Upper Jurassic consists of 2 sequences, which include shallow lake, lake shore and fluvial facies. The Lower and Middle Jurassic contain the hydrocarbon source rock. Jurassic sandstone is widely distributed in the area, and can be excellent reservoirs for gas, partly good reservoirs for oil.