乌审旗地区苏75井区盒8段沉积相及其展布特征

Sedimentary facies of He-8 member in Su-75 block of Wushenqi area and its distribution characteristics

结合岩心相标志和测井相标志,对乌审旗地区苏75井区10余口探井取心段岩石学特征、沉积构造现象、剖面结构的详细研究,认为苏75井区盒8段属辫状河沉积,发育河道和泛滥平原2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2个微相。在微相分析的基础上,编制了盒8段5个小层沉积微相平面图,揭示了河道心滩砂体呈南北向展布的规律。根据沉积微相平面展布图,结合工区沉积背景,建立了本区盒8段的沉积相模式。该成果为苏里格气田苏75井区盒8段气藏有效砂体的预测指出方向,也为水平井整体开发方案的制定和调整提供了地质依据。

According to the detailed study on the petrological characteristics,the sedimentary structures and the profile structure of the coring sections of more than 10 exploration wells in Su-75 block,as well as core facies marks and log facies marks,it is held that He-8 member is braided river deposit,and there are developed two subfacies of channel and floodplain. The channel subfacies can be further divided into two microfacies of channel-lag deposit and diara. The sedimentary microfacies plane graphs of 5 small layers of He-8 member are prepared,and they show that the diara sand-bodies present a north--south directional distribution. The sedimentary model of He-8 member is established based on the sedimentary microfacies plane graphs and the sedimentary setting of Su-75 block. The research results can provide the basis for the prediciton of the effective sand-bodies and the formulation and adjustment of the overall horizontal well development program of He-8 member in Su-75 block.