【摘要】 运用地震与沉积相结合的方法对永安镇油田沙四段冲积扇－扇三角洲体系进行了较详细研究。指出冲积扇－扇三角洲体系在地震剖面上具有两种反射形态：陡坡楔形体及陡坡丘形体，并认为前者形成时间早于后者。在对冲积扇－扇三角洲岩石学研究的基础上，识别出了６种岩相，结合地震剖面，划分了沉积亚相及主要微相。通过对岩相及沉积构造组合关系的分析，总结出了冲积扇－扇三角洲辫状水道沉积的３种类型及水道前缘沉积的２种主要类型。更多还原

【Abstract】 It is proved that there are two reflection patterns of alluvial fan-fan delta system in Sha-4 member wedge and dune-like. On the basis of studying on petrology, six lithofacies are distinguished. According to the seismic section, rock features and sedimentary fabric, fan-delta plain, fan -delta -edge, ptofan -delta and chief microfacies can be divided. There are obvious differences among the facies in hydrodynamic conditions and sedimentary features. Authors summarize three depositional models in braided channels and two depositional models in channels front of fan-delta edge, based on the studying of constituting-relation between lithofacies and structures .更多还原