鄂尔多斯盆地寒武系张夏组和三山子组储层形成机理研究

发布时间：2018-03-13 16:35

本文选题：碳酸盐岩　切入点：地球化学特征　出处：《成都理工大学》2017年博士论文　论文类型：学位论文

【摘要】：论文以鄂尔多斯盆地下古生界上寒武统三山子组与中寒武统张夏组为研究对象,在前人研究成果、钻井及地震勘探取得的实物资料基础上,结合野外地质调查、实测精细地层剖面,运用沉积学、岩相古地理学、地球化学、储层地质学等学科理论,采用点、线、面,野外与室内结合、宏观与微观结合、常规研究与先进测试分析方法结合等工作方法,综合研究鄂尔多斯盆地寒武系沉积相、沉积环境及其演化,储层岩石类型、储集空间、储层物性及地球化学特征,成岩作用类型及对储层的影响,系统分析了储层的成因及主控因素。论文主要取得了如下认识与成果:(1)通过沉积环境分析,将鄂尔多斯盆地中上寒武统划分出碳酸盐岩台地沉积体系、台地边缘沉积体系、斜坡-盆地沉积体系三大沉积体系,其中碳酸盐岩台地沉积体系又可进一步划分出台地潮坪、局限台地及开阔台地相;台地边缘沉积体系可进一步划分出台地边缘浅滩、台地边缘生物礁、台地边缘斜坡相;斜坡-盆地沉积体系可进一步划分出上斜坡、下斜坡、盆地边缘及深海平原相。(2)以层序地层学理论为指导,分别编制了张夏组与三山子组的岩相古地理图,确立了张夏期与三山子期均发育五种古地理单元:(1)剥蚀古陆、(2)潮坪相、(3)局限台地-开阔台地相、(4)台缘斜坡相、(5)陆棚-深水盆地相。建立了沉积模式,阐明了沉积演化过程。(3)通过储层岩石学研究认为,鄂尔多斯盆地寒武系碳酸盐岩储层岩石类型以粉-细晶白云岩为主;储集空间类型有晶间孔、溶孔、溶洞、粒间孔、裂缝。(4)储层地球化学特征显示:张夏组与三山子组白云岩具有明显不同的稀土配分型式,表明其具有不同的白云岩化机理;三山子组白云岩δ13CPDB与海水相当,δ18OPDB在5‰的狭小范围内变化,表明其白云岩化作用流体以海水为主,结合其岩相学特征,判定为回流渗透白云岩化作用。(5)寒武系碳酸盐岩储层受沉积相、溶蚀作用、白云岩化作用、埋藏作用多方面控制,在储层形成后的埋藏期发生致密化,其致密化过程可概括为:成岩早期压实?早期硅化/重结晶作用(孔隙度变化不大)?抬升溶蚀/填充作用(或持续深埋)?(再次埋藏)压溶/重结晶(油气充注)?深埋溶蚀作用?充填及重结晶作用?构造抬升破裂/角砾化作用(或持续埋深)?淡水淋滤/硅化/去白云岩化作用(或持续埋深)?充填作用。
[Abstract]:The Erdos in the lower Paleozoic Cambrian three mountain group and Middle Cambrian Zhangxia group as the research object, on the basis of previous research results, the real data based on the drilling and seismic exploration, combined with the geological survey, the measured fine stratigraphic section, using sedimentology, lithofacies palaeogeography, geochemistry, reservoir geology theory, using point, line, surface, indoor and outdoor combination, the combination of macro and micro, conventional research and advanced testing methods with other methods of work, the comprehensive study of Erdos sedimentary basin facies, sedimentary environment and its evolution, reservoir rock type, reservoir space, reservoir properties and geochemical characteristics. Diagenesis and its effect on reservoir system, analyzes the causes and main controlling factors of the reservoir. The main results of this paper are as follows: (1) understanding and achievements through the analysis of sedimentary environment, the Erdos Basin Cambrian is divided into carbonate platform sedimentary system, platform margin depositional system, sedimentary basin slope system three depositional system, carbonate platform sedimentary system is further divided into introduction of tidal flat, restricted platform and open platform facies platform margin; sedimentary system can be further divided into introduction to the edge of the edge of the shoal, biological reef platform, platform margin slope facies; slope basin sedimentary system can be further divided into upper slope, lower slope, basin edge and abyssal plain. (2) based on the theory of sequence stratigraphy, were compiled Zhangxia group and the three group of mountain lithofacies palaeogeography map is established, and three mountain Zhangxia period both the development of five kinds of palaeogeographic units: (1) land erosion, (2) (3) tidal flat facies, restricted platform open platform facies, platform margin slope facies (4), (5) the shelf deep-water basin facies. Established sedimentary model, the sedimentary evolution . (3) through the study of reservoir petrology, Erdos basin Cambrian carbonate reservoir rocks with fine crystal dolomite; reservoir space types include intergranular pore, dissolved pore, cave, intergranular pores, cracks. (4) show the geochemical characteristics of reservoir: Zhang Xiazu and Zi three dolomite has different REE patterns, indicating that it has different dolomitization mechanism; three mountain group dolomite Delta 13CPDB and waters, changes in narrow scope of delta 18OPDB in 5 in 1000, showed that the dolomitization fluid in seawater, combined with the petrographic characteristics, determine the permeability of dolomitization to return. (5) the Cambrian carbonate reservoir sedimentary facies, dissolution, dolomitization, burial effect control, densification occurs in the reservoir after the formation of the burial period, the densification process can be summarized as follows: the early diagenetic compaction and silicification early? / recrystallization (porosity changes little)? / filling effect (or uplift erosion continued buried)? (buried again) pressure dissolution / recrystallization (oil and gas)? Deep buried dissolution and recrystallization? Filling? Tectonic uplift rupture / brecciated effect (or continuous depth) of fresh water? The leaching / silicide / to dolomitization (or continuous depth)? Filling effect.

【学位授予单位】：成都理工大学
【学位级别】：博士
【学位授予年份】：2017
【分类号】：P618.13

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