【摘要】 运用层序地层学原理,结合钻井、测井和地震资料分析,在塔北—塔中地区三叠系识别出5个层序界面,将三叠系划分为4个三级层序,在此基础上建立了塔北—塔中地区三叠系的层序地层格架,并对地层格架中的沉积充填特征进行了分析。认为三叠系属于内陆坳陷盆地在聚敛期沉积的一套地层,发育3类沉积体系,从盆地边缘向盆地内部依次为(扇)辫状河三角洲、滨浅湖、半深湖、深湖相。研究区发育4种储集砂体,单独或配合发育可形成砂体上倾尖灭、砂岩透镜体、(水下)分流河道等多种圈闭,是寻找三叠系岩性油气藏的理想目标区。更多还原

【Abstract】 The drilling performance curve,well logs and seismic data are analyzed using sequence stratigraphy theory,and five sequence interfaces of Triassic in Tabei-Tazhong area,Tarim basin,which belong to Type-I sequence interfaces except SI-2 and SI-3 belonging to Type-II.Based on these interfaces,the Triassic can be divided into four Class-3 sequences,hence the sequence stratigraphic framework of the Triassic in this area is developed and its sedimentary characteristics are analyzed.It is suggested that the Triassic belongs to a set of strata deposited in convergent period in inland downwarping basin with three types of sedimentary systems characterized by varied facies distributions of braided fluvial delta,coastal lake,semi-deep lake,deep lake along the basinal margin toward the basinal interior.The composite analysis indicates that the studied area develops four types of reservoir sands,which could form multiple traps by separated or matching development,such as updip pinch-out,lenticular sand and underwater distributary channel.They are the ideal targets for lithologic reservoirs of the Triassic in this area.更多还原