【摘要】 以层序地层学、地震沉积学和现代沉积学理论为指导,对塔北地区128口井的录井资料和测井资料、近2.5×104 km二维地震剖面和部分三维地震数据体进行了综合分析。在塔北地区三叠系中识别出5个以不整合面为界面的三级层序,层序Tsq1和层序Tsq2相当于下三叠统,层序Tsq3和层序Tsq4相当于中三叠统,层序Tsq5相当于上三叠统。5个层序均由低位体系域和湖侵体系域组成,低位体系域以发育辫状河、曲流河和三角洲为主,湖侵体系域以发育滨浅湖、半深湖和深湖为主。构造运动、湖平面变化和物源供给是控制三叠系层序形成的主要因素。层序演化及石油地质条件分析表明,低位体系域中发育的复合河道和三角洲分流河道是寻找岩性圈闭的有利目标。更多还原

【Abstract】 By means of sequence stratigraphy,seismic sedimentology and modern sedimentology theory,the comprehensive analysis of the logging and well logging data from 128 wells,25 000 km 2-D seismic profile and a part of 3-D seismic data in Tabei area is conducted,and five 3rd-order sequences(Tsq1-Tsq5) bounded by unconformities are identified in the Triassic.Tsq1 and Tsq2 belong to the Lower Triassic,Tsq3 and Tsq4 belong to the Middle Triassic and Tsq5 belongs to the Upper Triassic.All the five sequences are composed of the low-stand system tract dominated by braided river,meandering river and delta and the transgressive system tract dominated by littoral-shallow lake,semi-deep lake and deep lake.The tectonic movement,lake level change and sediment supply are the main controlling factors of the Triassic sequences.According to the analysis of sequence evolution and petroleum geology conditions,the complex channel and delta distributary channel developed in low-stand system tract are favorable explorative targets for lithological trap’s reservoirs.更多还原