鄂尔多斯盆地罗庞塬地区长7沉积微相研究

on the Sedimentary Microfacies of Chang 7 in the Luopangyuan Area of the Ordos

罗庞塬地区长7储层底部广泛发育的张家滩高阻泥岩,为中生界优质烃源岩,源储接触关系明显,砂体含油饱和度高,是勘探开发的重要储层。以岩心观察的岩石相标志及测井相分析为基础,通过地层砂地比、单井相剖面的相序分析,对鄂尔多斯盆地罗庞塬地区长7储层沉积相类型及发育规律进行了综合研究。结果表明,其主要沉积体系属于河流三角洲相和湖泊相沉积体系,发育三角洲前缘亚相和深湖-半深湖亚相,主要沉积微相类型包括有水下分流河道、水下天然堤、分流间湾、浊积水道、湖泥。根据沉积微相展布和演化规律可以得出研究区的沉积模式。

Zhangjiatan high resistivity mudstone is widely developed at the bottom of the Chang 7 reservoir in the Luopangyuan area,which is a high-quality source rock of the Mesozoic era.The source reservoir contact relationship is obvious,and the sand body has high oil saturation,making it an important reservoir for exploration and development.Based on the rock facies indicators observed by rock cores and the analysis of logging facies,a comprehensive study was conducted on the sedimentary facies types and development patterns of the Chang 7 reservoir in the Luopangyuan area of the Ordos Basin through the analysis of the stratigraphic sand to land ratio and the facies sequence of single well facies profiles.The results indicate that its main sedimentary system belongs to river delta and lake facies sedimentary systems,with the development of delta front subfacies and deep lake semi deep lake subfacies.The main sedimentary microfacies include underwater distributary channels,underwater natural embankments,inter distributary bays,turbidite channels,and lake mud.Based on the distribution and evolution of sedimentary microfacies,the sedimentary model of the study area can be obtained.