珠江口盆地东沙隆起惠州地区珠江组碳酸盐岩下段沉积微相研究

发布时间：2018-02-28 16:17

本文关键词： 东沙隆起珠江组微相相模式　出处：《成都理工大学》2015年硕士论文　论文类型：学位论文

【摘要】：位于南海北部的珠江口盆地所发育的下中新统珠江组碳酸盐岩是我国海相碳酸盐岩的最高层位,它记录了新近纪以来南中国海气候变化、生物演化、海平面升降和构造沉降等丰富的地质信息。前人对下中新统珠江组的研究主要集中在流花、陆丰、白云凹陷等地区的碳酸盐岩上段,这是因为这些地区钻井资料相对丰富,而且大量的钻井取心均来自碳酸盐岩上部,为研究碳酸盐岩的矿物学、岩石学和沉积微相提供了实物资料。而碳酸盐岩下段的地层因为实物资料的相对欠缺,研究较少,这制约了人们对珠江组沉积环境和沉积演化规律的客观科学认识。因此本文依托国家“十二.五”重大专项海洋深水区油气勘探关键技术子课题《南海北部深水区碳酸盐岩储层识别技术与评价》,以中海油深圳分公司近年在东沙隆起惠州地区实施的HZ28-1-1等5口钻井的岩心、岩屑、录井和测井资料为第一手资料,综合运用沉积地质学、古生物地层学、岩相古地理和地球物理测井基础原理等理论和方法,对珠江组下段碳酸盐岩的矿物学、岩石学、古生物、测井响应特征和沉积微相进行详细研究,取得如下认识:1.根据研究区274块薄片的矿物学、岩石学和古生物的研究结果,在东沙隆起惠州地区珠江组下段识别出了粉砂质泥质岩、有孔虫泥粒岩、有孔虫屑藻屑泥粒岩、生物碎屑泥粒灰岩、含生物碎屑粒泥灰岩、生物碎屑粒泥灰岩、含内碎屑藻屑泥粒岩、藻灰岩和藻粘结岩等9种沉积微相类型;根据这些沉积微相对环境的指示,惠州地区珠江组下段碳酸盐岩属于混积陆棚、缓坡、台地边缘和浅水陆棚4种沉积环境的产物。2.基于对珠江组碳酸盐岩下段微相和沉积相的研究,初步分析了珠江组碳酸盐岩下段沉积可以分为4个期次。第I期:随着海平面的上升,陆源碎屑注入的减少,整个东沙台地为混积陆棚环境,混积沉积主要集中在研究区的东部,而惠州地区则为碳酸盐岩陆棚的泥微晶灰岩沉积;第II期:由于海平面的下降,之前的混积陆棚演变为碳酸盐岩缓坡,惠州地区处于缓坡的高能相带,沉积物质以含珊瑚藻屑泥粒岩和白云石藻屑有孔虫泥粒岩为主;第III期:中中新世中期,东沙隆起由碳酸盐岩缓坡演变为碳酸盐岩台地,惠州地区由之前的缓坡高能相带演变为台地边缘的礁滩相带,沉积物质以藻屑有孔虫屑泥粒岩、珊瑚藻屑泥粒岩和有孔虫珊瑚藻屑泥粒岩为主;第IV期:碳酸盐产率跟踪相对海平面上升,台地边缘规模进一步扩大,在惠州东部呈条带状分布,沉积物质以珊瑚藻屑泥粒岩为主。
[Abstract]:The carbonate rock of the Lower Miocene Pearl River formation developed in the Pearl River mouth basin in the northern part of the South China Sea is the highest layer of marine carbonate rocks in China. It records the climate change and biological evolution of the South China Sea since the Neogene. The previous studies of the Pearl River formation of the Lower Miocene are mainly focused on the upper carbonate rocks in Liuhua, Lufeng, Baiyun Sag and other areas, because these areas are relatively rich in drilling data. Moreover, a large amount of drilling coring comes from the upper part of carbonate rock, which provides material data for the study of mineralogy, petrology and sedimentary microfacies of carbonate rock. This restricts the objective scientific understanding of the sedimentary environment and sedimentary evolution law of the Pearl River formation. Therefore, this paper relies on the key technology of oil and gas exploration in the deep sea area of China's 12 Five-Year Plan < Deep Water in the North of the South China Sea. Identification Technology and Evaluation of Carbonate Reservoir in the area. Core of HZ28-1-1 and other drilling wells implemented by CNOOC Shenzhen Branch in Huizhou area of Dongsha uplift in recent years, According to the theories and methods of sedimentary geology, paleontological stratigraphy, lithofacies paleogeography and geophysical logging, the mineralogy and petrology of carbonate rocks in the lower part of the Pearl River formation are studied. Paleontology, logging response characteristics and sedimentary microfacies were studied in detail, and the following understandings were obtained: 1.According to the mineralogical, petrological and paleontological results of 274 thin slices in the study area, Silty mudstone, foraminiferal mudstone, foraminiferal dregs, bioclastic mudstone, bioclastic marl, bioclastic marl, bioclastic marlite have been identified in the lower member of the Pearl River formation in Huizhou area, Dongsha uplift. According to the indication of these sedimentary microenvironments, carbonate rocks in the lower member of Zhujiang formation in Huizhou area belong to mixed continental shelf and gentle slope. The products of four sedimentary environments of platform margin and shallow shelf. 2. Based on the study of the microfacies and sedimentary facies of the Lower Carbonate member of the Pearl River formation, The sediments of the lower carbonate rocks of the Pearl River formation can be divided into four stages. Phase I: with the rise of sea level and the decrease of the injection of terrigenous debris, the whole Dongsha platform is a mixed continental shelf environment. The mixed deposits are mainly concentrated in the eastern part of the study area, while the Huizhou area is the mud microcrystalline limestone deposit of the carbonate shelf, the second stage: because of the sea level drop, the former mixed shelf evolved into the carbonate rock gentle slope. Huizhou area is located in the high-energy facies belt of gentle slope, the sedimentary material is mainly composed of coral-bearing algal dregs and dolomite algal debris foraminiferal mudstone, and the III stage: in the middle Miocene, the Dongsha uplift evolved from carbonate rock gentle slope to carbonate platform. Huizhou area changed from the gentle slope high-energy facies belt to the reef shoal facies zone on the platform margin. The sedimentary materials are algal debris foraminiferal mudstone coral algal debris mudstone and foraminiferal algae-dreglite. Stage IV: carbonate yield tracked relative sea level rise, the scale of platform margin further expanded, distributed in the eastern part of Huizhou, the sedimentary material was mainly coral algal mudstone.
【学位授予单位】：成都理工大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：P588.245;P618.13

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