【作者】 刘吉全；

【导师】 张世奇；

【作者基本信息】 中国石油大学 ， 矿产普查与勘探， 2010， 硕士

【摘要】 车排子凸起是准噶尔盆地的一个重要勘探区块,勘探实践表明,新近系沙湾组具有良好的油气成藏潜力。论文针对车排子地区新近系进行沉积体系研究,其中主要目的层段为沙湾组和塔西河组。论文以层序地层学、沉积学、石油地质学等理论为指导,结合野外露头资料、岩芯资料、地震资料、测井资料、录井资料等多种地质资料,运用构造、地质、测井、地震、层序、沉积等多种学科分析为手段,对车排子地区新近系进行了层序地层学、古物源、沉积体系等方面的研究。对车排子地区新近系沙湾组和塔西河组进行了层序划分,识别出4个三级层序界面,划分出3个三级层序,其中层序Ⅰ对应沙湾组的沙一段,层序Ⅱ对应沙二段和沙三段,层序Ⅲ对应塔西河组;在层序划分的基础上,结合层序界面和体系域界面特征,对每个层序识别出低位域、湖侵域和高位域三个体系域。在此基础上,以体系域为基本单元,建立了车排子地区新近系沙湾组和塔西河组的等时层序地层格架。应用地层沉积构造特征、砂岩成分成熟度分析等方法,确定了工区西北部的扎伊尔山北麓山前区为新近系物源的供给区。以现代沉积学理论为指导,以单井相分析、连井相分析、地震相分析、平面相分析为前提,结合物源分析、构造背景等资料,在车排子地区识别出两种沉积体系:辫状河三角洲体系和湖泊体系。辫状河三角洲体系在层序Ⅰ、层序Ⅱ的低位域和湖侵域时期发育辫状河三角洲前缘亚相,水下分流河道和河道间沉积为其主要微相;在层序Ⅱ高位域和层序Ⅲ地层则主要发育辫状河三角洲平原亚相,沉积辫状河道和冲积平原微相。湖泊体系主要发育滨浅湖亚相,滨浅湖泥沉积为其主要微相,其次滨浅湖为砂坝微相。详细论述了各体系域时期内两大体系的平面展布情况。建立了新近系沉积相发育模式。更多还原

【Abstract】 Chepaizi salient is one of the important exploration blocks in Junggar Basin,the exploration and practice data show that there’s potentiality to find oil and gas fields in the Neogene Shawan Formation. This paper proposes the research of the depositional systems of the Neogene strata in Chepaizi area,and take the Shawan Fm and Taxihe Fm as the major target layer. Considering the guidance of theories of sequence stratigraphy, sedimentology, geology of petroleum and so on, including the information of field outcrop,rock core,seismic,well logging,mud logging and so on, we did a systematic research on sequence stratigraphy, sediment sources,depositional systems for Neogene strata in Chepaizi area. By the methods of structural geology and tectonics,geology,logging,seismic,sequence stratigraphy,sedimentology etc..The Neogene Shawan Formation and Taxihe Formation in Chepaizi area was recognized four third order sequences interfaces and divided into three third order sequences,and the SQ1 corresponding to N1s1,the SQ2 corresponding to upper N1s2 and N1s3,the SQ3 corresponding to Taxihe Formation;On the basis of the sequence division,combined with sequence boundaries and systems tract boundaries characters,we recognized three systems tracts in every sequence,the result as follows:lowstand systems tract,transgressive systems tract,high systems tract. Then we established isochronous stratigraphic framework of N1s and N1t in Chepaizi area.By using sedimentary tectonic features,maturity analysis of sandstone composition etc.,we found that the source area of northern foot of Mt Zaire is the source supply area of Neogene. Guiding with the theory of modern sedimentology,considering single well facies analysis,across-well analyses,seismic facies analysis,synthetic analyses of sedimentary facies and combined with provenance analysis,tectonic background ect., braided delta depositional system and lake system are recognized from Chepaizi area. At the period of lowstand systems tract and transgressive systems tract of the SQ1 and SQ2 of Braided Delta Depositional System,braided fluvial delta front were developed ,among which the underwater distributary channel and mouth bar are the main facies belts; and at the period of high systems tract of SQ2 and SQ3,there is a chief subfacies and several microfacies,such as braided river delta plain subfacie, braided distributary channel and flood plain microfacies. For the lacustrine system, the chief subfacies is coastal and shallow lake which mainly produce the mud in offshore-shallow lake microfacies,and there is also sand bar microfacies. The planar distribution of the two Depositional systems in every periods of system tract was discussed in details, and the evolution model of Neogene sedimentary facies are built.更多还原