【作者】 庞军刚；

【导师】 李文厚；

【作者基本信息】 西北大学 ， 矿物学、岩石学、矿床学， 2006， 硕士

【摘要】 本文综合子洲-清涧地区野外剖面、岩芯以及各项地质基础资料,运用沉积相分析及地质理论,进行了上古生界地层划分,物源分析,沉积相类型识别,沉积相带与砂体展布等研究,对研究区上古生界沉积体系有了较深入认识。 通过本次研究,取得了以下的重要认识: 依据标志层、岩电特征、沉积旋回,参考勘探开发实践,对研究区上古生界地层进行了对比划分,并详细地描述了各层的地层特征,同时,首次应用高分辨率层序地层的理论和方法进行了层序地层的划分,并与岩性地层划分方案进行了对比。 在区域地质背景及沉积体系展布研究的基础上,结合轻、重矿物组合的平面变化,分析了研究区上古生界的物源方向。研究表明,研究区的碎屑主要来源于盆地北部的浅变质结晶基底。 根据野外剖面、钻井岩芯及测井相分析,认为子洲-清涧气区上古生界主要发育辫状河三角洲、三角洲、湖泊、障壁海岸及浅海陆棚5种沉积体系。进一步识别出本溪组的障壁岛-泻湖、太原组潮坪-浅海陆棚、山₂³～山₁¹三角洲前缘和盒₈²、盒₈¹辫状河三角洲前缘等亚相。两类三角洲均为建设性浅水台地型三角洲,以三角洲前缘水下分流河道广泛发育,河口坝不发育为主要特征,水下分流河道构成三角洲前缘的骨架砂体,也是研究区天然气的主要储集体。 微量元素分析认为山西组以淡水沉积为主,但间或的受海水内泛的影响,在此基础上,笔者探讨了不同沉积微相与砂体在空间的展布特征,并提出了三角洲的沉积模式,分析了其沉积演化。 在探讨了上古生界天然气富集及有利储集砂体的影响因素后。根据砂体展布,顶面构造及勘探开发实践,对重点层位有利气区进行了预测。更多还原

【Abstract】 Applied with outcrop observation,core description and other geophysical basic data, the theories of sedimentary facies and geology are applied, Stratum division ,the source of clast, sedimentary facies types, the distribution of sedimentary facies and sand body are studied in this thesis. Sedimentary system developed in Upper Paleozoic are deeply studied.By the above research ,the following important innovations are obtained:According to the sign layer, the character of lithology and electromotive curve, sedimentary cycle, consulting the practice of exploration and exploitation, the lithology stratigraphy are divided, the characteristic of strata are discussed,respectively. Viewpoint and method of high resolution sequence stratigraphy are firstly applied in study area, and high resolution sequence stratigraphy are divided ,and are compared with traditional strata division.On the basis of the background of areal geology and the distributing of diverse sedimentaty system analyzing, combined with the variety of light and heavy mineral association, the origin of clast composing of sandstone are analysed when Upper Paleozoic are deposited ,the result shows that they are origined in low grade metamorphic crystal fundus in north of the Ordos Basin.It is held that Paleozoic stratum is composed of five sedimentary system by outcrop, well core,logging facies,including braided delta, meandering delta, lacustrine and so on. The sedimentary system can be further divided into following microfacies: barrier island - lagoon in Ben-xi formation, tidal level ground and shallow marin shelf in Tai-yuan formation, normal delta front in Shan₂³ Shan₁¹ and braided river-controled delta front in He₈^2He₈¹, and the two types of delta system are both shallow mesa delta system with high constructive, charactered by subaqueous distributary channel being highly developed,while, bayou bam being not well developed.therefore,the sandy body of subaqueous distributary channel ,not only the framework sandstone of delta front subfacies ,but also the main sandstone for gas accumulation in study area.Microelement testing shows that the water in paleoenvironment mainly is freshwater,but is influenced by seawater at long intervals.On the basis of these described above, the characteristic of depositional system and sandy body in space are discussed. Besides,depositional model of delta system are constructed and depositional evolvement are analysed by the author.After gas accumulation and favorable sandstone influence factors are discussed. According to the distributing of sandy body , top conformation and the practice of exploration and exploitation in study area, favorable region in the main aim segment are forecasted.更多还原