川东北元坝地区飞仙关组台缘沉积结构及鲕粒滩时空响应

发布时间：2018-03-16 07:34

本文选题：鲕粒滩　切入点：台地边缘沉积结构　出处：《成都理工大学》2017年硕士论文　论文类型：学位论文

【摘要】：四川盆地东北部包括了九龙山背斜构造带、池溪凹陷、通南巴背斜构造带和苍溪—巴中低缓构造带,具有较长的碳酸盐岩油气勘探历史。根据已有的工业钻井资料及前人研究资料显示,区内下三叠统飞仙关组有很好的勘探潜力。目前基于高精度等时地层格架的台缘几何形态演化、内部沉积体系构成及空间变化的研究有待开展。为此,本论文针对川东北元坝地区飞仙关组台缘沉积展开研究,结合前人资料和钻井资料补充,对飞仙关组台缘沉积进行小波变换、Fischer图解等详细研究,建立高精度等时地层格架,总结分析飞仙关组台地边缘结构及沉积体系空间分布和鲕粒类型的空间演化,得到以下结论和认识:(1)川东北元坝地区飞仙关组可划分为SQ1和SQ2两个三级层序,且两个层序由高水位体系域和海侵体系域组成,均缺失低位体系域。飞一段和飞二段为SQ1,飞三段和飞四段为SQ2。在地震和钻井资料约束下,尝试性开展了基于小波变换和Fischer图解联合约束下的高精度层序地层的划分和对比工作,SQ1时期,在对开江—梁平海槽进行填平补齐,陆棚相区的沉积厚度较其它两个相区大,高频层序发育较不均衡。SQ2时期,元坝地区碳酸盐岩台地基本形成,高频层序发育较为均衡。总体认为两种方法的叠合能有效地进行高精度层序地层的综合分析,但是Fischer在不同的相带位置结构差异明显,针对不同相带应选择性应用。(2)基于地震、野外露头和钻井资料综合分析,系统开展了元坝地区飞仙关组沉积相类型构成分析,飞仙关组可识别出局限台地、开阔台地、台地边缘、台地边缘斜坡和陆棚等沉积相,进一步划分了沉积亚相类型,并揭示了各自的基本特征。(3)系统揭示了台地边缘鲕粒类型构成及垂向分布特点,鲕粒具多成因特点,室内镜下鉴定出真鲕、表鲕、放射鲕、复鲕和同心鲕等原生沉积鲕粒,以及白云石化鲕、压实变形鲕、负鲕、重结晶鲕和破裂鲕等后期改造鲕粒。同时,揭示鲕粒具有多层段分布特点,飞一段、飞二段、飞三段均有,以飞二段为主,并揭示鲕粒类型在垂向上具有一定的分异性的特点。(4)基于地震、钻井等资料,系统开展了飞仙关组海平面变换及台地沉积结构特征及演化研究,研究揭示,飞仙关组台缘沉积结构总体的向东明显前积的结构特点,并具有早期SQ1TST海侵退积、SQ1HST早期具有缓慢海侵,鲕滩开始生长,SQ2晚期,快速海退鲕滩大面积发育,并快速向东前积的沉积结构特点。到飞二段晚期,由于开江梁平陆棚的填平补齐,研究区主要演化为局限台地—台地蒸发岩。进而形成了飞一段退积、飞二段快速进积和飞三—飞四段加积的沉积结构样式,而鲕粒滩沉积主体时期的飞二段,其早中晚期鲕粒的平面分布特征具有一定的差异性。在该沉积结构基础上,形成对应性的鲕粒滩时空分布规律,并建立了飞仙关组早期前积迁移的沉积模式。
[Abstract]:The northeast Sichuan basin includes Jiulongshan anticline structural belt, Qixi sag, Tongnanba anticline structural belt and Cangxi-Bazhong low-moderate structural belt. It has a long history of oil and gas exploration in carbonate rocks. According to the existing industrial drilling data and previous research data, The Feixianguan formation of the Lower Triassic in this area has good exploration potential. At present, the research on the geometry evolution of the platform margin based on the high-precision isochronous stratigraphic framework, the composition of the internal sedimentary system and the spatial variation of the sedimentary system need to be carried out. In this paper, based on the research of platform margin deposition of Feixianguan formation in Yuanba area of northeast Sichuan, combining with previous data and well drilling data, we have carried out wavelet transform Fischer diagram and other detailed studies on the platform margin deposition of Feixianguan formation, and set up a high-precision isochronous stratigraphic framework. Based on the summary and analysis of the spatial distribution of platform marginal structure and sedimentary system and oolitic type of the Feixianguan formation, the following conclusions and understandings are obtained: the Feixianguan formation in Yuanba area, northeast Sichuan, can be divided into two third-order sequences: SQ1 and SQ2. The two sequences are composed of high water level system tracts and transgressive system tracts, both of which are missing low system tracts. The Fei-1 and Fei2 are SQ1, Fei3 and Fei4 are SQ2.Under seismic and drilling data constraints, The division and correlation of high-precision sequence stratigraphy based on the combination of wavelet transform and Fischer diagram were carried out tentatively in SQ1 period. During the period of SQ1, the sedimentary thickness of shelf facies was larger than that of the other two facies areas, in the filling and leveling of the Kaijiang-Liangping trough, and the sedimentary thickness of the shelf facies was larger than that of the other two facies regions. During the period of unbalanced development of high-frequency sequence. SQ2, carbonate platform in Yuanba area was basically formed, and high-frequency sequence was relatively balanced. It is generally considered that the combination of the two methods can effectively carry out comprehensive analysis of high-precision sequence stratigraphy. However, there are obvious differences in the location and structure of Fischer in different facies belts. In view of the selective application of different facies belts, based on the comprehensive analysis of seismic, outcrop and drilling data, the composition analysis of sedimentary facies types of Feixianguan formation in Yuanba area has been carried out systematically. The Feixianguan formation can identify the sedimentary facies, such as limited platform, open platform, platform margin, platform margin slope and shelf, and further divide the sedimentary subfacies. The basic characteristics of each system are also revealed. The system reveals the composition and vertical distribution of oolitic grains on the edge of the platform, the characteristics of the oolitic grains with multiple genesis, and the primary sedimentary oolitic grains, such as true oolitic, superficial oolitic, radiative oolitic, complex oolitic and concentric oolitic, etc. At the same time, it is revealed that the oolitic particles have the characteristics of multilayer distribution, such as Feiyi, Fei-second, Fei-3, and mainly Fei-second, and so on, in the later stage of oolitic transformation, such as dolomitization, compacted deformed oolitic, negative oolitic, recrystallized oolitic and ruptured oolitic. It is also revealed that oolitic types have some distinct characteristics in vertical direction. (4) based on seismic and drilling data, a systematic study on the sea level transformation and platform sedimentary structure and evolution of the Feixianguan formation has been carried out. The sedimentary structure of the platform margin of the Feixianguan formation has the characteristics of eastward obvious forward accumulation, and the early SQ1TST transgressive regressive sedimentation SQ1HST has slow transgression in the early stage, the oolitic beach began to grow in the late stage of SQ2, and the rapid regressive oolitic beach developed in a large area. And the characteristics of sedimentary structure of rapid eastward forward deposition. By the late stage of Feijiangliangping continental shelf, the main evolution of the study area was limited platform platform evaporite, and then formed the Feiyi retrogradation. There are some differences in the plane distribution characteristics of oolitic oolitic beach oolitic oolitic beach in the rapid precession of the second stage and the accumulation of the fourth member of the third and fourth member of the Feiyi formation, and the difference of the plane distribution of the oolitic particles in the early, middle and late stages of the oolitic beach sedimentary stage, based on the sedimentary structure. The corresponding spatial and temporal distribution of oolitic beach was formed, and the sedimentary model of early forward migration of Feixianguan formation was established.
【学位授予单位】：成都理工大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：P618.13

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