中上扬子地区早三叠世飞仙关期岩相古地理研究

发布时间：2018-06-22 05:39

本文选题：中上扬子地区 + 早三叠世　；参考：《长江大学》2015年硕士论文

【摘要】：中上扬子盆地是我国南方大型的含油气叠合盆地,盆地沉积盖层发育比较齐全。通过数十年的勘探,目前已经发现了诸如渡口河、铁山坡、罗家寨、普光、毛坝、通南巴、龙岗、元坝等气田以及众多的油苗和古油藏,这些均显示中上扬子盆地具有良好的油气勘探及开发前景。岩相古地理研究是油气勘探工作的基础。对其展开系统全面的研究,有助于弄清岩相古地理的分布和演化规律,阐明其与烃源岩、储集岩和盖层发育的关系,从而指导油气勘探。近十几年来,前人对中上扬子地区下三叠统的构造特性、岩石学特征、沉积相演化、烃源岩类型、储层、圈闭条件等方面都进行了研究,但是很长一段时间之内岩相古地理的研究仍然是以定性为主,定量的研究较少。因此,有必要对中上扬子地区下三叠统进行全面透彻的定量岩相古地理研究,同时也能为油气勘探提供充分的基础资料。本文以中上扬子地区下三叠统飞仙关阶为研究对象,通过对实测、观察、钻井剖面的分析,结合多种分析手段,深入研究了各岩石类型特征及成因,并阐明了其沉积环境；采用冯增昭教授倡导的“单因素分析多因素综合作图法”对中上扬子地区早三叠世飞仙关期进行了定量岩相古地理研究,并在此基础上对研究区下三叠统飞仙关阶的生烃条件、储集条件和盖层条件进行了分析。中上扬子地区下三叠统由下至上可分为嘉陵江阶和飞仙阶。其中飞仙关阶包括飞仙关组、夜郎组、大冶组等。由下至上可以分为四段,分别为飞一段、飞二段、飞三段、飞四段。研究区下三叠统飞仙关阶的主要岩性为碳酸盐岩,次为碎屑岩、火山碎屑岩及蒸发岩。其中碳酸盐岩中石灰岩较白云岩发育,依据岩石成分、结构、构造,石灰岩可细分为颗粒石灰岩(包括鲕粒石灰岩、内碎屑石灰岩、生屑石灰岩)、灰泥石灰岩、泥灰岩、泥质石灰岩、蠕虫状石灰岩、瘤状石灰岩、白云质石灰岩；白云岩主要分为颗粒质白云岩、细晶—中晶白云岩、泥晶一粉晶白云岩三种类型；碎屑岩分为砂岩、粉砂岩、泥岩、页岩；火山碎屑岩主要为凝灰岩；蒸发岩主要为膏岩。中上扬子地区早三叠世飞仙关期的沉积环境可分为冲积平原、碎屑岩台地、浅水碳酸盐台地、斜坡及深水盆地；浅水酸盐岩台地可进一步划分出滩、准滩、雏滩,云坪,含膏盐湖等次级环境单元。本文选取的单因素包括地层厚度、深水沉积岩含量、浅水碳酸盐岩含量、颗粒碳酸盐岩含量、准同生白云岩含量、石膏及石盐含量,分四个编图单位绘制了飞仙关阶各单因素图件。通过单因素图件分析与区域地质资料、其它研究成果相结合,进行了综合分析,最终编绘出了早三叠世飞一亚期、飞二亚期、飞三亚期、飞四亚期定量岩相古地理图。研究区早三叠世飞仙关期总体上是一个海退的过程,继承了晚二叠世长兴期的古地理格局,飞一亚期古地理单元自西向东依次发育了古陆、冲积平原、碎屑岩台地、浅水碳酸盐岩台地、斜坡、碳酸盐岩盆地,碳酸盐岩台地发育了滩、雏滩、准滩、云坪等次级古地理单元；飞二亚期古地理单元由西向东的展布与飞仙关一期大体相同,浅水碳酸盐岩台地发育了滩、雏滩、准滩、云泥坪等次级古地理单元；飞三亚期古地理单元由西向东的展布与飞一、二亚期也大体相同,浅水碳酸盐岩台地发育了滩、雏滩、准滩、含膏盐湖、云坪等次级古地理单元；飞四亚期古地理单元由西向东依次发育了古陆、冲积平原、碎屑岩台地、浅水碳酸盐岩台地、盆地斜坡逐渐消亡,浅水碳酸盐岩台地发育了滩、雏滩、准滩、云坪、含膏盐湖、云泥坪等次级古地理单元。总体上,研究区格局概括为：西部有陆、主体为台、台上有滩、有云坪、有盐湖,东北缘有斜盆。在岩相古地理研究的基础上,对研究区早三叠世飞仙关期生油岩、储集岩和岩相古地理的关系进行了探讨。研究区内飞仙关阶发育了有利的烃源岩和储集岩,有利生油相带主要为较深水盆地、斜坡及部分局限台地；储集岩分布范围广,厚度较大,有利的储集相带主要发育于研究区的中西部,并沿颗粒滩相发育；在研究区西部的四川盆地,嘉陵江组和雷口坡组的膏盐岩是飞仙关组油气的直接盖层,四川盆地和江汉盆地的上三叠统至侏罗系厚达上千米的泥岩、粉砂质泥岩可以做为良好的区域性盖层。
[Abstract]:This paper studies the structural characteristics , petrology characteristics , sedimentary facies evolution , source rock types , reservoir and trap conditions of Upper Yangtze Basin .
In this paper , a quantitative petrographic palaeogeography study is carried out in the early Triassic Feixiguan period in the Middle Yangtze region by using the " single factor analysis multi - factor comprehensive mapping method " advocated by Prof . Feng Zengzhao . The main lithology of the Lower Triassic Feixiguan stage in the upper Yangtze region is carbonate rock , which is divided into four sections , namely Feixiuguan Formation , Night Lang Group , Daye Formation and so on .
The dolomite is divided into three types : granular dolomite , fine - grained - medium - grained dolomite and micrite - dolostone .
The clastic rock is divided into sandstone , silt , mudstone and shale ;
The pyroclastic rocks are mainly limestone ;
The sedimentary environment of early Triassic Feixiguan stage in the Middle Yangtze region can be divided into alluvial plain , clastic rock platform , shallow water carbonate platform , slope and deep water basin .
Based on the analysis of single factor graph and regional geological data and other research results , a comprehensive analysis is carried out .
The spreading of the ancient geography unit from west to east is the same as that of Feixiuguan Phase I , and the secondary paleogeographic units such as beach , shod beach , quasi - beach and Yunmud flat are developed in shallow water carbonate platform .
The spreading of the ancient geography unit from west to east in FeiSanya stage is similar to that of the first and second sub periods , and the secondary paleogeographic units such as beach , shod beach , quasi - beach , gypsum - containing salt lake , Yunping , etc . are developed in the shallow carbonate platform .
In this paper , the relationship between the crude oil rocks , the reservoir rocks and the palaeogeography of Feixiuguan period in the early Triassic in the study area is discussed . The main hydrocarbon source rocks and the reservoir rocks are developed in the study area .
The distribution range of reservoir rocks is wide , the thickness is large , the favorable reservoir facies belt is mainly developed in the midwest of the research area , and is developed along the grain beach ;
The gypsum - salt rocks in the western Sichuan basin , Jialingjiang Formation and Leikoupo Formation in the west of the study area are the direct caprocks of Feixiuguan Formation , the Upper Triassic to Jurassic in the Sichuan Basin and the Yangtze Basin to the mudstone of Upper Jurassic , and the silty mudstone can be made as a good regional cap layer .
【学位授予单位】：长江大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：P618.13;P534.51

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