东海陆架盆地闽江凹陷中生代层序地层格架与沉积体系研究

发布时间：2018-01-31 04:09

本文关键词： 闽江凹陷中生代层序地层格架沉积体系　出处：《中国石油大学(华东)》2015年硕士论文　论文类型：学位论文

【摘要】：东海陆架盆地是发育于东海大陆架之上的一个中新生代叠合盆地。经过近50年的勘探,在新生代地层中已获得重大油气突破,而中生界基础地质研究薄弱,严重制约了下一步油气勘探。前人研究证明闽江凹陷中生界具有重大的油气资源潜力。论文综合应用地震资料、钻井资料、测井资料、分析测试资料、区域地质资料等,在沉积学理论和层序地层学理论的指导下,建立了东海陆架盆地南部闽江凹陷及其周围地区的二级层序地层格架。通过对钻井资料的重点分析重新厘定了工区中生界的沉积环境。结合地震相分析明确了格架内部沉积体系展布规律,结合中生代古地理背景的分析建立了工区侏罗系和白垩系的沉积模式,对工区下一步油气勘探具有重要的指导作用。通过对地震剖面的层序地层学分析将东海陆架盆地南部地层划分为五个构造层序,其中,中生界可划分为两个构造层序。在单井上进行中生界三级层序界面识别,可将中生界划分为7个三级层序。受限于地震资料的品质在区域上只建立了闽江凹陷及其周围地区的二级层序地层格架。前人认为闽江凹陷中生界主要为陆相河湖相沉积,本次研究通过工区仅有的10米中生界岩心的详细观察描述以及对其他分析化验结果的分析,发现了典型的海相沉积相标志,如滨浅海相的羽状交错层理、海相海绿石、颗石藻、海绵骨针等;地球化学标志也指示有机质来源于低等海洋浮游生物。综合分析认为闽江凹陷中生界为滨浅海相沉积。在岩心相分析的基础上,结合地震-沉积相综合分析,总结了东海陆架盆地南部的地震-沉积相解释模板及工区主要发育的沉积相类型。认为该区中生界主要发育的沉积相类型为冲积扇相、三角洲相、河流相(瓯江凹陷)以及浅海相(闽江凹陷及以东);沉积体系类型有冲积扇-河流-三角洲-湖泊沉积体系(主要分布于瓯江凹陷)以及滨浅海沉积体系(主要分布于闽江凹陷及其以东地区)。结合地震层序的展布特征分别绘制了工区侏罗系和白垩系沉积体系展布图。通过对雁荡低凸起和台北低凸起形成演化史的研究,结合沉积体系研究成果,分别总结了工区侏罗纪和白垩纪的沉积模式。认为侏罗纪末雁荡低凸起的形成对东海陆架盆地南部中生界的沉积格局产生了重大的影响。
[Abstract]:The East China Sea shelf basin is a Mesozoic and Cenozoic superimposed basin developed on the continental shelf of the East China Sea. After nearly 50 years of exploration, major oil and gas breakthrough has been obtained in the Cenozoic strata, but Mesozoic basic geological research is weak. The previous studies have proved that the Mesozoic in Minjiang sag has great potential for oil and gas resources. This paper synthetically applies seismic data, drilling data, logging data and analyzing test data. The regional geological data are guided by sedimentology theory and sequence stratigraphy theory. The secondary sequence stratigraphic framework of Minjiang sag and its surrounding area in the south of the East China Sea shelf basin is established. The sedimentary environment of the Mesozoic in the working area is redefined through the analysis of drilling data. The distribution of depositional system in the frame is regular. Based on the analysis of Mesozoic paleogeographic background, the sedimentary models of Jurassic and Cretaceous in the working area are established. Through the sequence stratigraphic analysis of the seismic profile, the southern strata of the East China Sea shelf basin can be divided into five tectonic sequences. The Mesozoic can be divided into two tectonic sequences. The Mesozoic third-order sequence interface is identified on a single well. The Mesozoic can be divided into seven third-order sequences. Limited by the quality of seismic data, only the second-order sequence stratigraphic framework of Minjiang sag and its surrounding area has been established in the region. Lacustrine deposits. Through the detailed observation and description of the only 10 meters Mesozoic core and the analysis of other analysis results, the typical marine sedimentary facies markers, such as the plume interlaced bedding of the shoreline shallow facies, are found in this study. Marine aquamarine, alga, spongy bone needle and so on; Geochemical markers also indicate that organic matter originated from lower marine plankton. It is considered that the Mesozoic in Minjiang sag is shoreline marine facies. On the basis of core facies analysis combined with seismic-sedimentary facies comprehensive analysis. The seismo-sedimentary facies interpretation model and the main sedimentary facies types developed in the southern part of the East China Sea shelf basin are summarized. It is considered that the main sedimentary facies developed in the Mesozoic in this area are alluvial fan facies and delta facies. Fluvial facies (Oujiang depression) and shallow sea facies (Minjiang depression and east of Minjiang depression); Sedimentary system types include alluvial fan fluvial deltaic lacustrine sedimentary system (mainly distributed in Oujiang sag) and shoreline sedimentary system (mainly distributed in Minjiang sag and its east area). Based on the distribution characteristics of seismic sequences, the sedimentary systems of Jurassic and Cretaceous in the working area are mapped respectively. The evolution history of the formation of low uplift in Yandang and low uplift in Taipei is studied by means of the study on the evolution history of the depositional system in Yandang low uplift and Taibei low uplift. Combined with the research results of sedimentary system. The sedimentary models of Jurassic and Cretaceous in the working area are summarized, and it is considered that the formation of low uplift at the end of Jurassic has a great influence on the Mesozoic sedimentary pattern in the southern shelf basin of the East China Sea.
【学位授予单位】：中国石油大学(华东)
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：P618.13

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