【摘要】 通过乌什凹陷内5口钻井详细的岩心观察和测井曲线、实验室分析,认为乌什凹陷东部的下白垩统舒善河组是一套以红褐色砂砾沉积为主的陆源碎屑沉积,粒度粗,分选和磨圆均差。发育扇三角洲—湖泊沉积体系,扇三角洲平原的泥石流沉积和扇三角洲前缘水下分流河道十分发育,湖泊宽广而浅,主要沉积滨浅湖泥滩和较少量的以薄层状夹于滨浅湖泥岩中的砂坝。储层主要分布于舒善河组中段,即扇三角洲前缘水下分流河道砂岩段,砂岩成分类型为中细粒岩屑砂岩,属低孔低渗储层;沉积微相、砂岩粒度以及填隙物含量对储层储集性能影响很大。更多还原

【Abstract】 Based on detailed core observation,log analysis and laboratorial analysis of five wells of Wushi sag,it can be seen that the Lower Cretaceous Shushahe Formation is mainly developed in the eastern Wushi sag,which is a series of coarse terrestrial deposit,featuring redish brown sandy conglomerate with poor roundingand poor sorting.Fan delta and lake facies are the dominant types of sedimentary facies of Lower Cretaceous in the eastern Wushi sag.Debris flow deposits are common in fan delta plain subfacies,and submerged distributary channel largely develop in fan delta front.The lake was extensive and shallow,and grew shore-shallow lacustrine muddy banks and sand bars which were interbedded in the muddy banks as thin layers.The reservoir is middle-fine lithic sandstone and features low porosity and low permeability,developing in middle Shushanhe Formation,which is mostly fan delta front sand body.The controlling factors of effective reservoir were analysized through comprehensive study on sedimentary facies and reservoir characteristics: sedimentary micro-facies,sand grain size and interstitial material are decisive.更多还原