塔里木盆地奥陶纪岩相古地理恢复及其油气勘探意义

在对塔里木盆地9条露头剖面、320口钻井的岩心及980块岩石薄片观察基础上,依据测井相、地震相及地震剖面形态特征分析,结合地层沉积厚度恢复,编制了盆地奥陶纪蓬莱坝期、鹰山早期和晚期、一间房期及良里塔格期的岩相古地理图。蓬莱坝期至鹰山期,盆地表现为东西分异的沉积特点,一间房期至良里塔格期,盆地沉积格局变为南北分异,各个时期广泛发育台缘及台内礁滩体。认为台缘带和台内礁滩体是塔里木盆地奥陶系油气勘探的重要领域,其中台缘带是近期增储上产的现实领域,而台内礁滩体是潜在的勘探领域。

Reconstruction of Ordovician Lithofacies Palaeogeography and Petroleum Prospecting Significance in Tarim Basin

Based on the observations of 9 outcrop sections,320 well cores and 980 thinsections from Tarim Basin and combined with analysis of the shapes and features of image logging facies,seismic facies and seismic profiles,the Ordovician sedimentary thickness are reconstructed and five phases of Ordovician lithofacies palaeogeography maps of the basin are compiled.They are the maps of the Penglaiba(O1),the early and late Yingshan(O1-2),Yijianfang(O2) and Lianglitage(O3) ages.During Penglaiba to Yingshan ages,the sedimentation behaved difference in the east from in the west of the basin,and during Yijianfang to Lianglitage ages,the sedimention turn to be difference in the south from in the north of the basin because the tectonic stress of the Tarim plate margin transformed from extension to compression.Platform margin and inset reefs widely developed during every age.It is suggested that the Ordovician platform margin and inset reefs are an important domain for exploration and recent reserves increase in Tarim basin.