小拐油田夏子街组冲积扇沉积微相

小拐油田夏子街组冲积扇分为3个亚相和10个微相,扇顶亚相沉积物最粗,电阻率高,分为主槽、侧缘槽、槽滩、漫洪和泥石流微相;扇中亚相沉积物偏细,成熟度增高,分为辫流线、砂岛和漫流微相;扇缘亚相沉积物最细,流体能量最低,分为水道径流和片流微相。并根据冲积扇具有多源叠置、周边火山活动显着和玻屑凝灰质沉积普遍的特点,建立了沉积模式。

SEDIMENTARY MICROFACIES OF ALLUVIAL FAN IN\= XIAZIJIE FORMATION,XIAOGUAI OILFIELD

Xiazijie alluvial fan in Xiaoguai Oilfields could be divided into three subfacies and ten microfacies.Fanhead subfacies is composed of coarse sediments with high resistivity,and could be subdivided into main trough,side trough,trough beach,flood land and mudrock flow microfacies;the intrafan subfacies is composed mainly of fine grained sediments of high maturaty and could be subdivided into braided stream,sand island and difusion microfacies;the fan margin subfacies is composed of the finest grained sediments among the three subfacies with the lowest fluid energy,and could be further subdivided into radial water channel and laminar flow microfacies.The sedimentary model of the alluvial fan has been established based on its multisource,its evident volcanic activity and vitric tuff sediments.