南堡3号构造古近系层序地层格架及其演化研究

发布时间：2018-08-11 12:44

【摘要】：南堡3号构造位于南堡凹陷东南部,古近系以三角洲前缘和滨浅湖沉积为主,层序划分方案混乱,层序沉积充填过程不明确,沙河街组一段油藏分布规律不清。本文针对这些问题,以南堡3号构造古近系为研究对象,东营组二段—沙河街组一段为重点研究层段,综合岩心、钻测井、地震和分析化验等资料,开展了层序地层学及沉积学研究,建立了研究区等时层序地层格架,分析了研究区缓坡带层序地层特点及其控制因素、沉积充填演化特征以及层序地层格架与油气分布关系,为下一步油气勘探开发工作提供科学依据。主要取得了以下成果及认识:(1)在南堡3号构造古近系中识别了4个二级层序界面,9个三级层序界面,分为8个三级层序。其中SQ3-SQ7分为11个体系域,SQ5进一步分为4个准层序,SQ4湖退域分为2个准层序,建立了南堡3号构造古近系层序地层格架。(2)分析了古近系层序界面特点,阐明了各层序及其体系域发育特征。层序厚度由南西至北东方向总体呈增厚趋势,由北西至南东方向显示地层总体呈厚—薄—厚的发育特征,各体系域的沉积厚度分布受控于盆地边缘类型、构造活动、沉积物源等多种因素。(3)证实了研究区物源来自西南方向沙垒田凸起,古近系发育了四种沉积相:扇三角洲、辫状河三角洲、滨浅湖和深水滑塌浊积扇。其中扇三角洲—滨浅湖沉积主要出现在SQ1和SQ2中,辫状河三角洲—滨浅湖/浊积沉积主要出现在SQ3-SQ7中。(4)认为研究区控制层序发育主要因素为构造沉降、古气候和沉积物供给。归纳了沉积充填的层序结构样式有TSTRST(或HST)、TST=RST(或HST)、TSTRST(或HST)三种。建立了2种类型层序充填模式:无坡折带层序充填模式和具坡折带的层序充填模式,其中无坡折带层序充填模式为研究区主要层序充填模式。(5)指出研究区受层序地层格架影响的油气藏有3类:砂岩透镜体油气藏、砂岩上倾尖灭油气藏和构造—岩性油气藏。总结了岩性油气藏主要位于低位域的浊积扇体,湖侵域的浊积砂体或湖退域的单一的辫状河三角洲前缘水下分流河道砂体中。
[Abstract]:Nanbao No. 3 structure is located in the southeast of Nanpu depression. The Paleogene is dominated by delta front and littoral lake deposits. The sequence division scheme is chaotic, the sequence sedimentary filling process is not clear, and the reservoir distribution law of the first member of Shahejie formation is unclear. In this paper, the Paleogene of Nanbao No. 3 structure is taken as the research object, the section of the second stage of Dongying formation and the first member of Shahejie formation is taken as the focus of the study, the comprehensive core, drilling logging, seismic and analytical data are studied. In this paper, sequence stratigraphy and sedimentology are studied. The isochronous sequence stratigraphic framework is established in the study area. The characteristics of sequence stratigraphy in gentle slope zone and its controlling factors, the characteristics of sedimentary filling evolution and the relationship between sequence stratigraphic framework and oil and gas distribution are analyzed. To provide scientific basis for the next step of oil and gas exploration and development. The main achievements and understandings are as follows: (1) four second-order sequence interfaces and nine third-order sequence interfaces have been identified in the Paleogene system of Nanpu No. 3 structure, which are divided into eight third-order sequences. Among them, SQ3-SQ7 is divided into 11 system tracts and SQ5 is further divided into 4 quasequence and SQ4 lake regression. The sequence stratigraphic framework of Paleogene in Nanpu No. 3 structure is established. (2) the characteristics of Paleogene sequence interface are analyzed. The developmental characteristics of each sequence and its system tracts are expounded. The thickness of sequence shows an overall thickening trend from the south west to the north east direction, and from the north west to the south east direction shows that the strata are generally thick-thin-thick. The sedimentary thickness distribution of each system tract is controlled by the basin margin type and the tectonic activity, the sedimentary thickness distribution of each system tract is controlled by the type of the basin margin and the tectonic activity. (3) it is confirmed that the provenance of the studied area came from the uplift of the sand barrier field in the southwest direction, and four sedimentary facies were developed in the Paleogene: fan delta, braided river delta, shallow shore lake and deep water sloughing turbidite fan. Fan delta-shore-shallow lake deposits mainly occur in SQ1 and SQ2, and braided river delta-shore-shallow lake / turbidite deposits mainly occur in SQ3-SQ7. (4) it is considered that the main factors controlling sequence development in the study area are tectonic subsidence, paleoclimate and sediment supply. Three types of sequence structure styles of sedimentary filling are summarized: TSTRST (or HST) TST (or HST) TSTRST (or HST). Two types of sequence filling models are established: sequence filling model without slope break zone and sequence filling model with slope break zone. The sequence filling model without slope break zone is the main sequence filling model in the study area. (5) it is pointed out that there are three types of oil and gas reservoirs affected by sequence stratigraphic framework in the study area: sandstone lens reservoir, sandstone updip tip-out reservoir and structure-lithologic reservoir. The lithologic reservoirs are mainly located in the turbidite fan body in the low position, the turbidite sand body in the lake transgression area or the single braided river delta front underwater distributary channel sand body in the receding area.
【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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