【作者】 王永斌；

【导师】 姜在兴；

【作者基本信息】 中国地质大学（北京） ， 矿产普查与勘探， 2008， 硕士

【摘要】 应用现代沉积学方法,在岩芯观察的基础上,进行单井沉积微相分析研究。综合运用地质、测井和录井资料,通过连井对比将剖面扩大到全区范围,详细研究大牛地气田太原组储层的沉积微相类型、沉积特征及沉积环境。明确各沉积体系的分布规律、砂体的展布特征,结合盆地和区域构造演化,建立盆地沉积模式;研究重点层段储层的沉积成因及控制因素,明确储层的主控因素;进行本区岩相古地理和沉积演化史研究,研究天然气富集的主控因素,为下一步勘探部署提供科学理论依据,并预测有利储集砂体和区带。通过对大牛地气田太原组10口取心井进行了岩心观察与精细描述,共识别出10种层理和16种岩石相。根据岩心特征和7口井镜下薄片的观察再结合测井资料的研究,我们识别出工区内3种沉积相,6种沉积亚相,13种沉积微相。认为太1段为障壁岛-潮坪沉积体系,太2段为辫状河三角洲前缘沉积体系,打破了以前认为太原组为单一的障壁岛-潮坪沉积体系的观点。在上面研究的基础上,绘制了9口单井相综合图,横4纵4八条连井剖面,2张沉积相平面图,对太原组沉积相从垂相和平面做了全面的分析,认为太原组的沉积相发育主要控制因素为陆源物源的供给。太1段障壁岛的走向为北东-西南走向,向陆方向发育潮坪和泻湖沉积,太2段水下分流河道走向为北东-西南,主河道贯穿整个工区,在河道末端发育河口坝和席状砂。根据261个岩心样品的物性分布统计,和23块岩石薄片的观察,工区太原组储层属于低孔低渗类型的储层。各微相的砂体物性差别较大,比较好的为河口坝、潮汐水道和水下分流河道,但确定是否为有效储气层,主要因素为砂体厚度,而水下分流河道、潮汐水道和障壁砂坝一般砂体较厚,河口坝次之,席状砂和砂坪的砂体厚度最小。利用前面研究的各主要微相物性统计,砂岩厚度分布,和沉积微相平面分布等成果,结合太1和太2段试气井的统计研究,得出太原组太1段勘探有利储集带为潮汐水道和障壁砂坝的砂体范围,太2段的有利储集带为水下分流河道砂体的分布范围。更多还原

【Abstract】 We analyzed the individual well microfacies by applying modern sedimentological methods and observation of drilling cores. On the basis of geological, logging and drilling materials, we enlarged the profiles to cover the whole area by correlation of well tie. Not only did we study the sedimentary microfacies types, sedimentary characteristics and sedimentary enviornment of reservoir of Taiyuan formation in Daniudi Gas Field, but we also studied the distributional pattern of sedimentary systems and sand bodies. By studying the regional tectonic evolution of basin, the sedimentary model of this basin was established. The sedimentary origin and controlling factor of the key research area were studied, and the master controlling factor of reservoir was clear, too. After researching the lithofacies paleogeology of this area, sedimentary evolutional history and the main controlling factor of gas accumulation, we could provide scientific theordial criteria of next exploration strategy and forecast beneficial reservoir sand bodies and interested zone.According to the observation and careful description of drilling cores of 10 wells of Taiyuan formation in Daniudi Gas Field, we recognized 10 types of bedding and 16 types of lithofacies. By drilling core characteristics, the observation of thin slices of 7 wells under microscope and the logging materials, we recognized 3 types of sedimentary facies, 6 types of sedimentary subfacies and 13 types of sedimentary microfacies. We held the viewpoint that Tai 1 member developed barrier island-tidal flat sedimentary system, and Tai 2 member developed braided-delta front sedimentary system, which challenged the conception that Taiyuan formation developed barrier island-tidal flat sedimentary system only.On the basis of the research before, we made 9 synthetic figures of individual well sedimentary facies, 8 well ties including 4 horizontal profiles and 4 vertical profiles, 2 sedimentary facies ichnographs. We analyzed the sedimentary facies of Taiyuan formation vertically and horizontally and held the viewpoint that the main controlling factor of sedimentary facies of Taiyuan formation is the terrigenous supply. The trend of barrier island of Tai 1 member is northeast-southwest direction. Tidal flat and lagoon deposits develop landwards. The trend of underwater distributary channel of Tai 2 member is northeast-southwest direction. The main channel goes through the work area, mouth bar and sand sheet develop at the end of the channel.According to the statistics of physical property distribution of 261 drilling core samples and the observation of 23 thin slices, we conclude that the reservoir of Taiyuan formation in the work area is low-porosity and low-permeability. The physical properties of sand bodies of microfacies differ a lot. The good reservoirs are mouth bar, tidal channel and underwater distributary channel. The main factor deciding whether the reservoir is effective is the depth of sand bodies. The depth of sand bodies of underwater distributary channel, tidal channel and barrier bar are relatively thick, the depth of sand bodies of mouth bar are less thick, the depths of sand bodies of sand sheet and sand flat are thin.According to the statistics of physical properties of every major microfacies, distribution of sandstone depth, sedimentary microfacies ichnographs, and the statistics of the gas testing wells of Tai 1 and Tai 2 member, we conclude that the beneficial zones of Tai 1 member are located at these places where tidal channels and barrier bars distribute, while the beneficial zones of Tai 2 member are located at these places where underwater distributary channels distribute.更多还原