松辽盆地伏龙泉断陷营城组构造—层序地层特征

发布时间：2018-01-10 10:13

本文关键词：松辽盆地伏龙泉断陷营城组构造—层序地层特征　出处：《中国地质大学(北京)》2017年硕士论文　论文类型：学位论文

【摘要】：伏龙泉断陷位于松辽盆地东南部,为一“东断西超”的半地堑,边界断层活动性的阶段性强弱变化控制着盆地的形成、发展与演化。目前,已在营城组发现良好的油气显示,预示着较好的油气勘探前景。因而本文以伏龙泉断陷营城组为研究对象,主要应用构造地质学、层序地层学与沉积学的基本理论与方法,综合地震、钻/测井、岩心以及测试分析等资料,开展构造-层序地层学研究。通过分析伏龙泉断陷营城组构造活动、盆地结构与古地貌特征,在层序界面识别基础上建立整个盆地的层序地层格架,明确层序格架内沉积相与沉积体系发育、演化特征,进而总结伏龙泉断陷营城组层序地层结构样式,探讨构造-层序-沉积之间的响应关系。为伏龙泉断陷油气勘探提供地质基础,也为类似的断陷盆地构造沉积学研究提供实例借鉴。伏龙泉断陷的3条主要边界断层控制了伏北、伏南与顾家店等3个次洼的形成、发展与沉积充填过程。营城组沉积期边界断层的活动性总体表现为“北强南弱,早期活动性较强、晚期逐渐减弱”的特点,其沉积早期构造古地貌呈现为“东西分带,北深南浅”的格局,并进一步划分出7种不同地貌单元。根据地震与钻井的层序界面识别,在伏龙泉断陷营城组识别出2个三级层序(SQ1与SQ2),每个层序进一步划分为低位体系域、湖侵体系域与高位体系域。综合岩心观察、薄片鉴定、钻/测井以及地震资料分析,伏龙泉断陷营城组发育扇三角洲、辫状河三角洲、水下扇以及湖泊等4种主要沉积相类型。从营城组早期至晚期,地层展布范围逐渐扩大,地貌差异减小,沉积物粒度总体变细,沉积、沉降中心由南向北迁移,沉积体系由早期的扇三角洲、水下扇-湖泊沉积转化为晚期的扇三角洲、辫状河三角洲-湖泊沉积。盆地构造样式在研究区南北不同区域存在明显差异,根据3种不同盆地结构形态、层序内部结构及沉积充填展布特征,伏龙泉断陷营城组发育3种典型层序结构样式:多级断阶型、平缓斜坡型与挠曲坡折型。综合分析表明伏龙泉断陷东侧3条主要边界断层活动的时空差异性对于层序的界面形成、可容纳空间变化以及层序内部构成特征也具有重要的控制作用。盆地发育的不同构造古地貌单元对沉积体系类型及展布控制明显,制约着砂体的分散与堆积。
[Abstract]:The Fulongquan fault depression is located in the southeast of Songliao Basin. It is a semi-graben with "east fault and west superimposed". The stage change of boundary fault activity controls the formation, development and evolution of the basin. A good oil and gas display has been found in Yingcheng formation, which indicates a good prospect of oil and gas exploration. Therefore, this paper takes Yingcheng formation in Fulongquan fault depression as the research object, and mainly applies structural geology. The basic theory and method of sequence stratigraphy and sedimentology, synthesizing the data of earthquake, drilling / logging, core and test analysis, are carried out to study the tectonic-sequence stratigraphy. The tectonic activity of Yingcheng formation in Fulongquan fault depression is analyzed. The basin structure and paleogeomorphology characteristics, on the basis of sequence interface identification, the whole basin sequence stratigraphic framework is established, and the sedimentary facies and sedimentary system development and evolution characteristics in the sequence framework are defined. The sequence stratigraphic pattern of Yingcheng formation in Fulongquan fault depression is summarized, and the response relationship between tectonics, sequence and sedimentation is discussed, which provides a geological basis for oil and gas exploration in Fulongquan fault depression. The three main boundary faults in the Fulong Quan fault depression controlled the formation of three sub-depression in Fubei, Founan and Gujiadian. The activity of boundary faults of Yingcheng formation during sedimentary period is characterized by "north strong south weak, early strong activity, late gradual weakening". The early sedimentary tectonic paleogeomorphology is characterized by a pattern of "east-west zonation, deep and southern shallowness in the north", and 7 different geomorphologic units are further divided, and identified according to the sequence interface between earthquakes and drilling wells. Two third-order sequences SQ1 and SQ2 were identified in Yingcheng formation of Fulongquan fault depression. Each sequence was further divided into low system tract, lacustrine transgressive system tract and high system tract. Based on drilling / logging and seismic data analysis, four main sedimentary facies types, namely fan delta, braided river delta, underwater fan and lake, were developed in Yingcheng formation, from the early to the late period of Yingcheng formation. The distribution of strata gradually expanded, the difference of geomorphology decreased, the grain size of sediment became finer, the sedimentation center moved from south to north, and the sedimentary system changed from the early fan delta. The subaqueous fan lacustrine deposits are transformed into late fan deltas, braided river deltas and lacustrine sediments. The structural styles of the basins are obviously different in different regions north and south of the study area, according to three different basin structure forms. The internal structure of sequence and the characteristics of sedimentary filling distribution, three typical sequence structural styles are developed in Yingcheng formation of Fulongquan fault depression: multistage fault terrace. The comprehensive analysis shows that the temporal and spatial differences of the three main boundary faults in the east side of the Fulongquan fault depression are related to the formation of the sequence interface. Different tectonic paleogeomorphic units developed in the basin control the type and distribution of sedimentary system obviously, which restrict the dispersion and accumulation of sand body.
【学位授予单位】：中国地质大学(北京)
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：P618.13;P539.2

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