塔里木盆地瓦石峡凹陷侏罗纪构造演化与油气地质条件  

Jurassic structural evolution and oil & gas geology conditions for Washixia Depression in Tarim Basin

作　　者：许怀智[1] 张岳桥[2] 王贵重 刘兴晓 周成刚 路鹏程 

机构地区：[1]南京大学地球科学与工程学院,江苏南京210093 [2]中国地质科学院地质力学研究所,北京100081 [3]东方地球物理公司研究院库尔勒分院,新疆库尔勒841001

出　　处：《石油地球物理勘探》2010年第1期129-135,共7页Oil Geophysical Prospecting

基　　金：东方地球物理公司"塔里木盆地新区;新领域勘探目标优选与评价"科研项目(41005070046)资助

摘　　要：本文基于地质露头剖面、地球物理、钻井等资料,分析了瓦石峡凹陷侏罗纪构造演化史、构造层序特征、油气地质条件,得出以下认识:瓦石峡凹陷侏罗纪构造演化划分为早侏罗世断陷、中侏罗世拗陷和晚侏罗世萎缩三大阶段;在侏罗系中共识别出5个重要层序界面(包括2个一级、1个二级和2个三级层序界面),并将侏罗系划分为1个一级、2个二级和4个三级层序,其中2个二级层序界面对应早侏罗世断陷期、中侏罗世拗陷期和晚侏罗世萎缩期的转换构造运动界面。早侏罗世晚期—中侏罗世早期是盆地烃源岩发育的主要时期,烃源岩的有机质类型以腐殖型为主。中侏罗统杨叶组暗色泥岩具有较高的有机质丰度,是该区主要的烃源岩,康苏组暗色泥岩属于较差的气源岩。侏罗系内幕的砂岩及砂砾岩与其上覆的泥岩、煤系地层构成主要的储盖组合。因此瓦石峡凹陷是塔里木盆地重要的油气勘探新领域。Based on geological outcrop sections,seismic data and drilling data,the Jurassic structural evolution history,structural sequence characteristics and oil & gas geology conditions in Washixia Depression were analyzed in this paper,the following understanding was reached:the Jurassic structural evolution in Washixia Depression were divided into three stages,they were Early Jurassic fault depression stage,Middle Jurassic depression stage and late Jurassic shrinkage stage.Five important sequence boundaries were identified (including two of first class boundaries,one of second class boundary and two of third class boundaries),so the Jurassic was divided into one of first class sequence,two of second class sequence and four of third class sequence,among them the two of second class boundaries corresponded to the transformation tectonic movement boundary of the Early Jurassic fault depression stage,Middle Jurassic depression stage and late Jurassic shrinkage stage.Early Jurassic late stage to Middle Jurassic early stage was the main period of the source rock development in the basin,organic type of the source rock was mainly the humic type,Yangye Formation dark mudstone in Middle Jurassic had relatively high organic abundance,it was the major source rock in this area,Kangsu Formation dark mudstone was relatively poor gas source rock,the sandstone and glutenite of Jurassic episode and its overburden mudstone and coal-bearing strata acted as major reservoir and seal assemblage.Therefore Washixia Depression is the oil & gas exploration frontier in Tarim Basin.

关 键 词：油气地质条件 构造演化史 塔里木盆地 侏罗纪 凹陷 中侏罗世早期 早侏罗世 层序界面 

分 类 号：P618.130.2[天文地球—矿床学]