苏里格气田北部下石盒子组盒8段沉积微相研究

摘要

通过对苏里格气田北部20余口钻井岩心的岩石学特征、沉积构造、剖面结构的详细研究,结合测井相标志和古生物标志,认为苏里格气田北部盒8段属辫状河沉积,发育河道和洪泛平原两个亚相.河道亚相可进一步划分为河床底部滞留沉积和心滩两个微相,往往组成向上变细的剖面结构,测井曲线一般为中-高幅的齿化或微齿化的箱形或钟形;洪泛平原亚相在剖面结构上表现为砂泥岩的不等厚互层,测井曲线多呈锯齿状.在微相分析的基础上,编制了盒8上和盒8下两个时期的沉积微相平面图,其显示出河道心滩砂体呈南北向展布的规律.根据沉积相的时空展布规律,建立了本区盒8段的沉积相模式.%The eighth member of the Shihezi Formation consists of braided stream deposits including the channel and flooding plain subfacies on the basis of petrography, palaeontology, sedimentary structures, sectional architectures and well logs of more than twenty wells in northern Sulige Gas Field. The channel subfacies may be subdivided into two sedimentary microfacies: river-bed lag deposits and channel bar. These sedimentary microfacies generally display fining-upward depositional sequences, and moderate- to high-amplitude box-shaped or bell-shaped well logs. The flood plain subfacies comprises the alternating beds of sandstone and mudstone, and exhibits zigzag well logs. The sedimentary microfacies analysis has led to the construction of the sedimentary facies plans and model for the eighth member of the Shihezi Formation.