塔里木盆地牙哈地区库车组沉积特征及演化

Sedimentary Characteristics and Evolution of Kuqa Group in Yaha,Tarim Basin

在岩心精确描述基础上,根据电测曲线和地震属性资料,分析研究区内的岩石类型、沉积结构与构造、沉积序列等相标志,结合区域沉降背景,得出研究区为泛滥平原上发育的曲流河沉积体系;并识别出河床、堤岸、河漫和牛轭湖4个亚相。在相认识的前提下,对南北-东西两个方向的沉积相连井剖面和工区沉积相平面加以研究,认为库车组自下而上沉积演化的规律是由平水期以河床为主的组合亚相,到高水位时期的以堤岸为主的组合亚相,最后再到洪泛期的河漫亚相,整体体现出了一个湖进上升半旋回的特征。

On the basis of core accurate description, as well as date of well logging and seismic attribute data, the study area rock types, sedimentary structure and tectonics, sedimentary sequences, etc, were analyzed com- bined with regional settlement context, it is believed that the study area is on a flood plain development meandering river depositional system. And it can be found that four types of sedimentary facies,including the bed phase, bank phase, river flood phase and oxbow lake. Under the premise of understanding phase, combining with the connect- ing well sedimentary facies sectional in North and South and the flat sedimentary facies, it is considered that the sedimentary environment evolution of Kuqa group from the botteom to the top is from the riverbed subfacies of low water level,through the embankment subfacies of high water level, to the floodplain of higher water level, a com- plete set of the lake into the rise hemicycle from the bottom to the top is development.