【作者】 杜凯；

【导师】 李文厚；

【作者基本信息】 西北大学 ， 矿物学、岩石学、矿床学， 2011， 硕士

【摘要】 华池地区处在鄂尔多斯盆地的最大的构造单元—陕北斜坡的西南部,它的主要含油层位是三叠系上统的延长组。伴随着勘探步伐的日渐加快和勘探程度的不断深入,华池地区长6和长8油层组勘探前景喜人。该文以沉积岩石学、盆地构造动力学等相关学科为基础,运用多样测试分析手段,对该区三叠系延长组长6和长8两个目的油层组的沉积相进行了全面的分析。在了解鄂尔多斯盆地三叠系延长组地层划分方案后,考虑到油田单位的实际生产情况和这次的论文创作目的,依托区内广泛且稳定分布的标志层,有效且充分利用测井资料,依据厚度原方法和沉积旋回性对该区长6和长8两个目的油层组展开了精细的地层划分和对比,自上而下分为长61、长621、长622、长623、长631、长632、长633、长81、长82共9个油层段,为后续研究打下了良好基础。综合运用轻重矿物统计对比法、古水流测量分析法及稀土元素配分对比法对两目的层的物源进行了系统分析,查明长6油层组在沉积时存在北东向和南西向共两个方向的物源,其中北东向为主要物源,南西向为次要物源；而长8油层组沉积时除上述两个物源外,还有西北部的物源,推测其来自贺兰山以西的阿拉善古陆。根据沉积相的划分与识别标志,确定研究区长6和长8油层组有曲流河三角洲相、辫状河三角洲相和湖泊相三种沉积相类型；有曲流河三角洲前缘亚相、前三角洲亚相、辫状河三角洲前缘亚相、前辫状河三角洲亚相、浅湖亚相、深湖亚相等沉积亚相类型,在这些亚相中发育有多种沉积微相；其中在长8油层组中不发育深湖亚相。长6和长8的油层组均发育不同微相下的沉积砂体,砂体的分布形态与规模决定于沉积相展布特征。长8油层组的主要砂体为水下分流河道砂体,但长6油层组中的砂体除了水下分流河道砂体外,还有一定数量的浊积岩砂体。水下分流河道砂体多呈条带形展布,而浊积岩体则呈朵形或扇状展布。对目的油层组沉积环境的系统分析,有利于为该区后续油气勘探和开发工作提供理论帮助。更多还原

【Abstract】 Huachi area is located in the southeast of the Shanbei Slope, the biggest tectonic units of Ordos Basin, its main oil-bearing bed is the Triassic Yanchang Formation.With exploration extent promoted and exploration step speeded, Chang8 and Chang6 oil beds take on a good exploration prospect. Based on Sedimentology Lithology, Basin Tectonic Dynamics and so on, using many kinds of analysis and testing methods, the sedimentary facies of Chang8 and Chang6 oil beds which belong to Triassic Yanchang Formation in Huachi area are studied well.According to the stratigraphic division scheme of Triassic Yanchang Formation of Ordos Basin, considering company’s practice, the aim of the dissertation, widely and stably ranging mark beds, well logging data, thickness gauge,and sedimentary cycle, we did delicate strata division on Chang8 and Chang6 oil beds. From top to bottom, it can be divided into 9 small beds. This is a good base for later work. Combining heavy and light minerals, paleocurrents and rare earth elements, provenance of the aim beds are analyzed and it is known that there are two kinds of provenances of different orientation about Chang8 and Chang6 oil beds. One is the northeast provenanace, the other is the southwest provenance. Of the two, northeast provenanace is of great importance. Besides, Chang 8 also has northwest provenance. It is probably from Longxi ancient land in the west of Helan mountain.In view of the marks of identifying and divising sedimentary facies, it is thought that Chang8 and Chang6 oil beds contain meandering river delta facie, braided river delta facie and lake facie. Of these facies, there exit meandering river delta front subfacie, meandering river predelta facie, braided river delta front subfacie, braided river predelta facies, shllow lake facie and deep lake facie. Apart from these, there are also many microfacies. Deep lake microfacie don’t exist in Chang8 oil bed. Sandbody of different microfacie exist in both Chang8 and Chang6 oil beds. Distribution of facies affects the distribution of sandbody. Underwater distributary channel sandbody is the main component in Chang8 oil bed, meanwile, besides underwater disrtibutary channel sandbody, turbidite is another chief sandbody in Chang6 oil bed. Underwater disrtibutary channel sandbodies mainly present bands and turbidites mainly appear flower-like or sector. Delicate study on sedimentary environment of the aim beds provides some theory for the futher exploration and development.更多还原