【作者】 王峰；

【导师】 田景春；

【作者基本信息】 成都理工大学 ， 沉积学， 2007， 博士

【摘要】 鄂尔多斯盆地是我国东部中生代能源矿产最丰富、保存最完整的一个大型内陆含油气盆地，盆内三叠系延长组不仅是我国陆相三叠系地层中研究最早、同时也是盆地最早获得油气发现的地层，因而多年来一直是油气勘探的主要目的层。论文通过大量的野外和室内的研究工作，对盆地延长组的沉积边界、物源方向及母岩性质、沉积体系及发育模式、层序地层、湖盆底形和岩性油藏等方面进行了较为系统的研究。文章运用构造分析、边界两侧的地层特征分析、边缘相分析以及地震分析等手段，对延长组的沉积边界范围进行研究，其中贺兰山西缘断裂带、六盘山西缘断裂带分别构成了盆地的西北和西南边界，盆地西部沿河西走廊可延伸到肃南，盆地的东部沉积边界向东可延伸至豫西、豫北及山西中西部地区；运用古水流方向、碎屑颗粒类型及特征、重矿物组合特征、石英阴极发光特征及稀土元素分配模式等方法，研究了盆地的物源情况，其中东北部物源来自阴山南侧的深变质岩，西南部物源来自秦、祁褶皱带及陇西古陆的变质岩和早古生代沉积岩，西北部物源来自贺兰山以西的变质岩和沉积岩，南部物源来自秦岭北坡的变质岩和碳酸盐岩。冲积扇、河流、三角洲、湖泊是区内主要的沉积体系类型，盆地东北部发育缓坡型曲流河三角洲沉积，西南部发育陡坡型辫状河三角洲沉积。通过沉积相特征的研究，建立了沉积相模式，分析了不同时期沉积格局和砂体展布规律。运用陆相层序地层学的原理和方法，将鄂尔多斯盆地延长组划分为1个构造(二级)层序，4个沉积(三级)层序，建立了延长组层序地层格架，对各沉积层序内盆地的充填演化进行了讨论。综合运用地层厚度等值线方法、沉积微相组合方法以及高分辨率层序地层学方法确定了坳陷湖盆三角洲前缘的坡折线，在古水深和地层厚度校正的基础上对延长期湖盆底部古地形进行恢复，建立相应的数字高程模型，进行三维可视化分析。系统总结了延长组岩性油藏的类型特征、富集规律及成藏要素，综合分析了湖盆底形对岩性圈闭的影响以及层序地层对岩性油藏的控制。更多还原

【Abstract】 Ordos basin is one of the large inland basin of abundant energy andmineral source of Mesozoic in the east of our country. And it was preservedintegrally. The Yanchang Formation of Triassic is not only researchedearly, but also the first obtain oil gas strata of the basin. For a numberof years, it is the primary target of oil and gas exploration. On the basisof substantive field and indoor practice development work, the boundaryof sediment, the source, the sedimentary system, the basin developmentmode, the sequence stratigraphy, the bottom shape of lake and thelithology reservoir were researched.By the analysis of tectonic, the character of stratigraphy and borderfacies of both sides and the seismic analysis, the boundary of sedimentof Yanchang Formation was researched. The fracture zone of the westHelanshan and the west Liupanshan constitute the northwest and southwestboundary. The west of the Basin can extend to the south of Gansu alongthe Hexi corridor. The east of the Basin can extend to the west of Helan,the north of Helan and the middle-west of Shanxi. By using paleocurrentdirection, clastic particles style and characteristic, heavy mineralcombination, quartz cathode luminescence and rare earth elementallocation model, we researched the source condition of basin. Thenortheast source came from the hypometamorphic rock of the south Yingshan.The southwest source came from fracture zone of the Qingling andQilianshan and Longxi block mass ’metamorphic rock and Eopaleozoicsedimentary rock. The northwestward source came from west Helanshan’metamorphic rock and sedimentary rock. The south source came from thenorth Qingling’ metamorphic rock and carbonatite.The primary facies are alluvial fan facies, fluvial facies, delta facies and lake facies. The northeast of basin upgrowth flat gradient typelake delta sedimentary system, the southwest upgrowth scarp braided streamdeltaic deposit system. The author found sedimentary facies model andanalysed the depositional pattern and ore mass unfold law in differentphases.The Yanchang Formation is divided into one tectonic sequence and fourthird-order sequences by use of theory and method of continental sequencestratigraphy. The framework of sequence stratigraphy of YanchangFormation was built. At the same time, the sediment and evolution of everysequence were discussed.By using the stratigraphy thickness method, the sediment microfaciescombined method as well as high resolution sequence stratigraphy meanssynthetically, the lake basin knickline was ascertained. On the bases ofthe emendation of fossil water deep and stratigraphy thickness, theancient landform of lake basin in Yanehang period was restored,homologous digital elevation model was erected, and triaxialityvisualization analyses was made.The characteristic, enrichment law and the element of lithologicreservoir accumulation was summarized. The impact that the bottomconfiguration of lake basin on lithologic trapas and the control of thesequence stratigraphy on lithologic reservoir were analysed.更多还原