大路沟二区延长组长6段沉积相与沉积模式

Sedimentary facies and model of Chang 6 member of Yanchang Formation in Dalugou District 2

对鄂尔多斯盆地靖安油田大路沟二区上三叠统延长组长6段岩石类型、砂岩岩石结构、沉积构造、古生物及测井相进行了详细研究,具体分析了其沉积相类型与特征。研究表明,研究区长6沉积时期发育曲流河三角洲沉积体系,亚相类型为三角洲前缘,发育水下分流河道、水下分流河道侧翼、河口砂坝、席状砂、分流河道间、分流间湾6种微相。根据研究区沉积体系和平面展布特征,建立了长6段沉积体系的沉积模式,分别为枝状砂体沉积模式和朵状砂体沉积模式。

This paper studies the rock types, sandstone structure, sedimentary tectonics, paleontologic evidence and electrofacies of Chang 6 member of Yanchang Formation of Upper Triassic in Daliugou District 2 of Jing＇an Oilfield, Ordos Basin. The types and characteristics of sedimentary facies are analyzed in detail. The results shows that during the Chang 6 reservoir sedimentary period, the meandering river delta sedimentary system develops, the meandering river delta facies develops a subfacies of delta front and the delta front develops six microfacies as underwater distributary channel, underwater distributary channel flanking, channel mouth bar, sheet sand, distributary interchannel and interdistributary bay. Based on the sedimentary system and plane distribution features, two sedimentary models were built, which are branch-shape and cloud-shape sand body sedimentary models.