准噶尔盆地陆东地区侏罗系层序地层及储集砂体成因类型

SEQUENCE STRATIGRAPHY AND SANDBODY GENETIC TYPES OF JURASSIC SYSTEM IN LUDONG AREA OF JUNGGAR BASIN

通过钻井、测井、地震、岩心观察与实验分析等综合研究分析，按层序划分的基本原则，在侏罗系识别出7个层序界面，相应划分出7个层序18个体系域，其中JSQ7在研究区被剥蚀，识别出层序界面SB7。储集砂体受层序格架控制，有利储集砂体多形成于湖平面相对下降的低位期。主要储集砂体成因类型包括辫状河三角洲水下分流河道砂体、辫状河河道砂体、冲积扇辫状水道砂体和滨浅湖滩坝砂体，其储集性能主要表现为中-低孔隙度、中-特低渗透率。辫状河三角洲水下分流河道沉积成因砂体较其他类型砂体储集物性稍好。

By means of the integrated data analysis of drilling, log, seismic interpretation, core observation and experimental analyses and so on and moreover according to the sequence division principles, seven sequence interfaces are identified in Jurassic system, and seven sequences and eighteen system tracts are correspondingly divided as well. Among them, Sequence ＂JSQT＂ is denuded in the research area and only Sequence Interface SB7 is identified. The reservoir sandbodies are controlled by sequence framework, the favorable reservoir sandstones are mostly formed in the lowstand system tract （LST） when the lake level relatively declines. The main reservoir sandbody types include the sandbodies of subaqueous distributary channels in braided river delta, channel sandbodies in braided river, braided channel sandbodies in alluvial fan, shallow-shore lacustrine beach bar sandbodies. They have middle to low porosities and middle to ultra low permeabilities. For the reservoir properties, the former is much better than the others.