四川盆地元坝地区吴家坪组层序沉积特征及油气勘探意义  

Sequence Deposition Characteristics and Hydrocarbon Exploration Significance of the Wujiaping Formation in Yuanba Area,Sichuan Basin

作　　者：季春辉[1] 段金宝[1] 熊治富[1] 缪志伟[1] 张雷[1] Ji Chunhui;Duan Jinbao;Xiong Zhifu;Miao Zhiwei;Zhang Lei(Exploration Company,SINOPEC,Chengdu 610041,China)

机构地区：[1]中国石化勘探分公司,成都610041

出　　处：《地质科技情报》2018年第4期146-152,共7页Geological Science and Technology Information

基　　金："十三五"国家科技攻关重大专项(2017ZX05005-004)

摘　　要：通过对野外露头和钻井资料的重新梳理,运用Vail经典层序地层学理论方法,对元坝地区吴家坪组进行了层序地层划分。结合三维地震资料分析,选择典型连井剖面进行地层层序对比,建立了等时层序地层格架,在层序格架内开展了沉积充填作用的研究。研究表明:(1)元坝地区吴家坪组地层划分为三段,吴一段底部岩性以泥岩、炭质泥岩及铝土岩为主,中上部为生屑灰岩,吴二段下部岩性为泥岩、泥灰岩,上部为生屑灰岩夹薄层硅质灰岩,吴三段岩性以厚层生屑灰岩为主,吴一段为一个三级层序SQ1,吴二、吴三段组成一个三级层序SQ2;(2)吴家坪组继承了茅口组的沉积格局,SQ1和SQ2早中期为碳酸盐岩缓坡沉积模式,SQ2晚期在峨眉地裂运动的拉张作用下,出现"台盆分异",具有发育台缘高能浅滩的沉积背景,且地震响应特征明显;(3)吴三段台缘高能浅滩储层发育,且具有"多元供烃、近源富集"的特征,生储盖配置好,成藏条件优越,展示了良好的勘探潜力。元坝地区吴三段发育台缘浅滩相储层这一认识将有利拓宽上二叠统油气勘探领域。In this paper,the sequence stratigraphic division of Wujiaping Formation in Yuanba area is made by using Vail classical sequence stratigraphic theory and on field outcrop and drilling data.Based on the analysis of 3-D seismic data,the typical sequence profiles were selected to form the isochronous sequence stratigraphic framework,and the depositional effect was analysed in the sequence frame.The study shows that：（1）The Wujiaping Formation in Yuanba area is divided into three sections,Wu Ⅰ,Wu Ⅱ and WuⅢ.The bottom lithology of WuⅠis mainly composed of mudstone,carbonaceous mudstone and bauxite,with debris limestone in the upper part and mudstone in the lower part,The lithology of WuⅡconsists of mudstone and clay lime stone in the lower part and debris limestone intercalated with thin layed siliceous limestone in the upper part.The lithology of WuⅢis dominated by thick layered debris limestone.WuⅠis a section of a three-level sequence SQ1,while WuⅡ and WuⅢsections are connected to form a threelevel sequence SQ2.（2）Wujiaping Formation has inherited the sedimentary pattern of the Maokou Formation,in which the early and middle SQ1 and SQ2 developed gentle slope deposition model of the carbonate rocks and the late stage of SQ2 was affected by the stretching of the Emei tectonic movement causing the ＂separation of platform and basin＂ with the sedimentary setting of the development of platform margin high energy shoal,showing the obvious seismic response.（3）The reservoir development of the high energy shoal in the three Wu sections is characterized by the ＂ multi-supply hydrocarbon and proximal source enrichment＂.The reservoir cover is well configured and the storage conditions are superior,indicating agood exploration potential.The understanding of the Permian reservoir in the Wujiaping Formation of the Yuanba area will benefit the field of the Upper Permian oil and gas exploration.

关 键 词：层序划分 台缘浅滩 勘探潜力 吴家坪组 元坝地区 四川盆地 

分 类 号：P539.2[天文地球—古生物学与地层学]