【作者】 马强；

【导师】 屈红军；

【作者基本信息】 西北大学 ， 矿物学、岩石学、矿床学， 2009， 硕士

【摘要】 鄂尔多斯盆地已发现的气藏主要位于盆地中北部,近几年在盆地南部的延长油区有新的发现,勘探潜力巨大,但研究程度不高,因此,对其展开地层、物源及沉积相研究有重要的意义。在综合区域资料基础上,以沉积学、石油地质学等学科最新理论为指导,以研究区钻井、测井、试气及周边露头等资料为基础,重点研究了研究区地层、物源、骨架砂体平面展布特征,分析了研究区沉积相特征及展布规律,确定了骨架砂体沉积相模式,结合研究区勘探实践,探讨了天然气聚集规律,为研究区下一步天然气勘探提供一定依据。主要成果及认识如下:地层对比剖面及地层等厚图显示出本溪组与太原组有明显的东厚西薄现象,反映出海侵方向来自东部,其余各组地层厚度较稳定;古流向及重矿物分析表明研究区山西组与石盒子组整体处于南北物源汇水区,其物源可分为东北、西北及南部三个方向,中部整体属于汇水区;沉积相分析表明研究区上古生界发育碳酸盐台地、海岸、湖泊、三角洲及辫状河三角洲沉积相;其中碳酸盐台地和海岸沉积发育在本溪组及太原组,山西组、石盒子组及石千峰组主体发育曲流河三角洲及湖泊相沉积,盒₈段与千₅段发育辫状河三角洲沉积;研究区骨架含气砂体的沉积微相是障壁岛砂体及三角洲前缘水下分流河道砂体;本溪组发育北东—南西向障壁岛砂体带;山西组、石盒子组及石千峰组底部发育向中部汇聚的四个三角洲前缘朵状体;研究区上古生界主要发育岩性气藏,烃源岩、有利相带控制的储层展布及有利构造位置（近源优相高部位）是天然气成藏主控因素,在此基础上,在研究区指出了4个有利勘探区带。更多还原

【Abstract】 Gas reservoir which had been discovered is located in the central and north of Ordos basin. The new discovery has been found in Yanchang region in southern basin these years, and it shows great exploration potential. But the research degree is lower. So the study on stratigraphy, source and sedimentary system has great meaning in this area. Based on the Sedimentology, Petroleum Geology and other theories, according to the data of drilling, logging, gas testing and outcrop, the stratigraphy, sediment source and planar distribution feature of the skeleton sand bodies are analyzed in the study area. The characteristics of sedimentary facies and distribution rules are also analyzied. The sedimentary facies model of skeleton sand bodies is summarized. Additionally, with the present exploration, the gas reservoir-forming rule is discussed. The research provides certain foundation for further gas exploration. The conclusions are as follows:The analysis of the profiles of stratigraphic correlation and isopach maps of stratigraphy, it reveals that the benxi and taiyuan formations are thick on the east and thin on the west. This phenomenon suggested that the transgression direction is from east. The thickness of other formations is stable. Furthermore, with the analysis of paleocurrent direction and heavy minerals, it shows that the shanxi and shihezi formations are located in the junction area affected by north and south source. The source is from northeast, northwest and south, the central part is placed in junction area.The analysis of sedimentary facies suggested that it developed carbonate platform, coast, lake, meandering river delta and braided river delta system. Among them, the carbonate platform and coast sediment were developed in benxi and taiyuan formations. Shanxi, shihezi and shiqianfeng formations developed meandering river delta and lake sediment, he8 and qian5 members developed braided river delta sediment.The sedimentary micro-facies of gas-bearing skeleton sand bodies in the study area is barrier island and deltaic front subaqueous distributary channel. The deposits of benxi formation is sand bodies of barrier island which extented from northeast to southwest. Shanxi, shihezi and bottom of shiqianfeng formations developed four deltaic front lobes which are convergent to the central.The gas reservoir type of Upper Paleozoic in the study area is lithologic gas reservoir. So the source rock, reservoir spreading controlled by favorable facies belt, and beneficial tectonic locations are the main factors of gas reservoir-forming. Based on all of these, four favorable exploration belts are predicted.更多还原