【作者】 康锐；

【导师】 苏春乾；

【作者基本信息】 长安大学 ， 矿物学、岩石学、矿床学， 2007， 硕士

【摘要】 本文以鄂尔多斯盆地三叠纪延长组长9、长10油层组为研究对象,运用沉积相分析及地质理论分析,进行了物源分析、沉积微相划分、沉积相展布分析,恢复了整个盆地在长9、长10期的古地理演化过程。从剖面露头观察、岩心描述、单井测井相和对比、粒度分析,结合砂体的平面展布形态,分析判定长9长10被划为湖泊、河流、冲(洪)积扇和三角洲等4种沉积相类型。并进一步识别出11种亚相,分别为:滨浅湖、半深湖、水下冲积扇、三角洲平原、三角洲前缘、曲流河河道、辫状河河道、河漫滩、扇顶、扇中、扇端。明确提出了,鄂尔多斯盆地延长组长9、长10油层组总体为湖相沉积,边缘以粗碎屑的河流一三角洲及各种扇体沉积为主。各沉积相带的平面变化基本上呈环带状展布,而砂体的发育情况则完全受控于沉积相的展布特征。西南部沉积体系砂体从环县至正宁,砂体形态主要呈东西向、北东向条带状展布,东北部沉积体系砂体连片性好,以朵状为主。结合区域地质背景分析,恢复研究区古地理面貌和演化过程。揭示了研究区沉积相空间分布规律及其古地理的演化特征。首次将长9三分长10两分绘制了全盆地沉积相图。通过古生物、沉积结构与构造、沉积韵律、沉积厚度与沉积旋回特征和测井相分析等,初步建立了整个盆地长9、长10油层组古地理演化特征及对长8古地理演化的影响。更多还原

【Abstract】 This paper investigates the Yanchang formation Chang 9 Chang 10 oil bearing beds in Triassic system of Ordors basin, using theories as sedimentology and geology. This paper also systemly investigates the sediment source, dividing of sedimentary microfacies, sedimentary facies and its distributions, Chang 9 Chang 10’s paleogeographic evolution was reconstructed all basin.Based analysis, on outcrop observation, core description, single well-log and sequence connecting-well section, the Chang 9 Chang 10 oil bearing beds can be divided into four kind of sedimentary facies such as lakes, rivers alluvial fans and deltas Furthermore, eleven kind of sedimentary facies are identified, namely shore and saucer fan, half-depth lake, underwater sedimentary fan, delta plain, delta front, meander riverbed, braided riverbed, flood plain, top fan, middle fan, foot fan. we conclude that main sedimentary facies of Chang 9 Chang 10 oil bearing beds is sedimentary of lacustrine, wide-dastic river-delta and kinds of fans in edge of basin. all kinds of sedimentary facies belt in the plane trend from annular deviding, the distributions of the sand bodies are controlled by deposition system. Southeast deposition system’s sand bodies’ configuration that has low component and textural maturity presents a band sharp of east-west and northeast-southwest trend from Huangxian to Zhengning. Northeast system’s sand bodies which have good continuity present a northeast-southwest trend in the plane.Combining with the analysis of geological background of the study area, the paleogeographic evolution and evolvement has been resumed, exposing the rules of distribution of sedimentary facies and the rules of the evolution of paleogeography in the research areas. Protracting firstly sedimentary facies map of Chang 9 that divided into tow segment, and Chang 10, which is divided into three. By analyzing the fossils, sedimentary structure, sedimentary cycle, rhythmic bedding and other criteria, we preliminarily established paleogeography evolutionary characteristics which had influenced Chang 8’s paleogeography evolution of Chang 9 Chang 10 oil bearing beds in the whole basin.更多还原