哈南地区阿尔善组三段沉积相研究

发布时间：2018-05-02 17:22

本文选题：哈南地区 + 阿尔善组三段　；参考：《西南石油大学》2017年硕士论文

【摘要】：二连盆地位于中国内蒙古自治区的中北部,是我国陆上大型沉积盆地之一。哈南地区位于二连盆地阿南凹陷东部的阿尔善构造带,阿尔善组油藏是哈南地区主力油藏之一,但是近几年的勘探效果不理想。通过大量前人理论研究,认为哈南地区阿尔善组发育近岸水下扇沉积。近岸水下扇是断陷湖盆陡坡带较为典型的沉积体系,在我国东部地区取得了大量的油气勘探突破,是重要的油气储集体。本论文的研究对近岸水下扇沉积体系研究具有较好的理论意义,对哈南地区进一步预测储层分布和老油田的挖潜、增储上产具有重要的实际意义。本文以哈南地区阿尔善组三段为研究对象,大量分析前人研究成果,在区域构造研究及地层研究的基础上,开展研究区地层对比及沉积物源分析,通过沉积相标志研究,总结阿尔善组三段各沉积微相特征,分析沉积相的演化及分布规律,分析阿尔善组三段的沉积模式,得到以下结论:哈南地区位于内蒙古二连盆地阿南凹陷内。阿尔善组是哈南地区主力油藏之一。阿三段为典型的砂砾岩体沉积,地层发育受古隆起、潜山及断层控制明显,整体表现为“北厚南薄”,在善南洼槽和哈东洼槽哈局部地层厚度可达200m以上,哈南潜山和东部莎音乌苏凸起有地层缺失。通过研究区内成分成熟度、岩屑组分含量的变化情况及岩性分析认为,存在北部、东部和南部三个物源方向;结合碎屑颗粒结构分析以为,北部的蒙古林凸起和东部的莎音乌苏凸起可能是主要物源区,南部的苏尼特隆起可能是次要物源区。哈南地区阿三段为近岸水下扇-湖泊沉积,近岸水下扇划分为扇根、扇中和扇端亚相,扇根分为主水道和主水道间微相,扇中又分为辫状水道、辫状水道间和扇中前缘三个微相。近岸水下扇体主要发育在阿三段底部,向上扇体发育变差,逐渐演变为湖泊沉积;扇体发育及沉积相带展布,受湖泊边缘断裂凸起、潜山及洼槽控制明显。湖盆边缘断裂、凸起边缘发育扇根亚相,潜山附近发育扇中亚相,洼槽区域多为扇端及湖泊沉积。研究区东部莎音乌苏凸起近岸水下扇发育较好,南部阿南斜坡发育一般,向哈南潜山-善南洼槽和哈东洼槽,逐渐过渡为湖泊沉积。近岸水下扇多发育在断陷盆地中,以重力流、近源沉积为主要特征。盆地伸展应力作用下,形成断陷湖盆,是近岸水下扇发育的构造环境。断陷湖盆中,同生断层形成的陡坡带是近岸水下扇发育需要的古地貌条件。湖盆边缘的古凸起,为扇体的发育提供了必备的沉积物质。盆地构造持续活跃、均匀沉降的湖侵时期,有利有大型水下扇体的发育。湖盆断裂边缘、潜山、洼槽等微地貌,控制了扇体内部亚相(扇根、扇中、扇端)的发育和分布。扇根的主水道和扇中的辫状河道砂砾岩体,是重要的油气储集体。
[Abstract]:Erlian basin is located in the north-central part of Inner Mongolia Autonomous region of China and is one of the large sedimentary basins on land in China. The Haman area is located in the Arshan structural belt in the eastern part of Anan depression in Erlian Basin. The Alshan formation reservoir is one of the main reservoirs in the Hannan area, but the exploration results in recent years are not satisfactory. Based on a large number of previous theoretical studies, it is considered that the Alshan formation developed nearshore subaqueous fan deposits. The near-shore underwater fan is a typical sedimentary system in the steep slope zone of the faulted lake basin. It has made a great deal of oil and gas exploration breakthroughs in the eastern part of China and is an important oil and gas reservoir. The research in this paper is of great theoretical significance to the study of near-shore underwater fan sedimentary system, and has important practical significance for further prediction of reservoir distribution, tapping potential of old oil fields and increasing reservoir and production in Hannan area. In this paper, taking the third member of the Alshan formation in the Haman area as the research object, a large number of previous research results are analyzed. On the basis of the regional structural research and stratigraphic research, the stratigraphic correlation and sediment source analysis are carried out in the study area, and the sedimentary facies markers are studied. The characteristics of each sedimentary microfacies of the third member of the Alshan formation are summarized, the evolution and distribution of the sedimentary facies are analyzed, and the sedimentary model of the third member of the Alshan formation is analyzed. The conclusions are as follows: the Haman area is located in the Anan sag of Erlian Basin, Inner Mongolia. Alshan formation is one of the main reservoirs in Hanan area. The third member is a typical sandy and gravelly rock mass, the strata are developed by paleouplift, the buried hill and fault are controlled obviously, and the whole is "thick in the north and thin in the south". The thickness of the local strata in Shannanwa trough and Hadongwa trough can be more than 200 m. Hanan buried hill and the eastern Shayin Usu uplift have a lack of strata. Based on the analysis of composition maturity, variation of cuttings content and lithology in the study area, it is concluded that there are three sources in the north, east and south, combining with the analysis of clastic grain structure, The Mongolia forest uplift in the north and the Shayinusu uplift in the east may be the main provenances, and the Sunita uplift in the south may be the secondary provenance. The A3 member of the Hanan area is a near-shore subaqueous fan-lake deposit, and the nearshore underwater fan is divided into fan roots, fan and fan end subfacies, the fan root is divided into the microfacies between the main waterway and the main watercourse, and the fan is divided into braided channels. There are three microfacies between the braided waterways and the front edge of the middle fan. The subaqueous fan body mainly developed at the bottom of the A3 member, and the upper fan body became worse and gradually evolved into lacustrine deposit, and the fan body development and sedimentary facies distribution were obviously controlled by the lacustrine edge fault protruding, buried hill and depression trough. The lacustrine margin is faulted, the uplift margin develops fan root subfacies, and the subfacies of fan near buried hill is developed. The depression area is mostly fan end and lacustrine deposit. In the eastern part of the study area, the nearshore subaqueous fan of the Shayinwusu uplift is well developed, and the southern Anan slope is generally developed, which is gradually transitioned to lacustrine deposit from the Hannan buried hill to the Shananwa trough and the Hadongwa trough. Offshore subaqueous fans are mostly developed in faulted basins, characterized by gravity flow and near-source deposition. The faulted lacustrine basin was formed under the action of extensional stress in the basin, which is the tectonic environment for the development of subaqueous fan in the nearshore. The steep slope zone formed by syngenic faults is the paleogeomorphic condition needed for the development of subaqueous fans in the near shore in the faulted lacustrine basin. The paleoprotuberance at the edge of the lake basin provides the necessary sedimentary material for the development of the fan body. The active and uniform subsidence of the basin during the period of lake transgression is favorable for the development of large underwater fan bodies. The development and distribution of subfacies (fan root, fan in fan and fan end) are controlled by microgeomorphology of lacustrine fault margin, buried hill, depression trough and so on. The main channel of fan root and the braided channel sandy gravel rock in fan are important oil and gas reservoirs.
【学位授予单位】：西南石油大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：P618.13

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