【摘要】 以高分辨率层序分析为指导思想,以岩芯和测井分析为基础,结合地震资料对荔湾3-1井区珠江组下部深水扇沉积层序界面和海泛面成因类型进行综合研究,探讨了深水扇短期旋回结构类型和分布规律,建立了主要产层时间—地层格架,并对地层格架中的小层砂体进行劈分和等时追踪对比,讨论了不同基准面旋回条件下储层发育特征。通过层序—岩相古地理编图,结合GR约束反演,刻画了不同发育阶段深水扇砂体展布特征,建立了深水扇水道砂体的时空间展布模式,对今后深水扇型油藏的砂体预测具有重要借鉴意义。更多还原

【Abstract】 Through the comprehensive analysis of cores,well logs and seismic interpretation data,and under the guidance of the theory and technology of the high-resolution sequence stratigraphy,the characteristics of the different grade sequence interface and marine flooding surface in the Lower Zhujiang Formation Miocene in Liwan3-1 Block are studied.In this paper,the sequence structure and distribution of the short sequence of deep water fan are discussed,and the sequence and time stratigraphic framework of main reservoir is established.The small sand body layers in stratigraphic framework of the Zhujiang Formation in the study area are isochronously correlated and wedged,and the reservoir developmental features of different base-level cycles are discussed.It indicates that the canyon on the continental slope is an activity location of sedimentary process.The canyon was filled by sandy silt quickly in base-level ascending phase.A majority of sediment was carried to much deeper sea area than the study area,and only little sediment preserved or even caused stratigraphic lacuna in the study area.The A/S value(the change of the accommodation space to sediment supply ratios) of short sequence increasing in a vertical direction,and it indicates that deepwater fan was moving towards to shore land.The moving of the main channel of deepwater fan is an important reason for the stratigraphic lacuna under the channel.The deposit in the deepwater fan channel is most active in base-level initial ascending phase,characteristics as active progradation sequence that have downlap and onlap,and it will be beneficial to develop reservoir sand bodies.Effective accommodation space and deepwater fan moving towards to the source area accompany with sea level rising to the maximum flooding surface.It developed retrogradation sequence in this period and argillic layers grow in number because of the channel moving frequently.Variation of the accommodation space corresponding to base-level ascending or descending is the major factor that control short base-level cycle types and reservoir distribution in deep water fan system.Accompanying with sea level descending and effective accommodation space moving towards to the deep-sea plain,sediment in the deepwater fan channel in the study area was carried to deeper sea area by gravity current,and it would be more beneficial to develop reservoir sand bodies to the south of Liwan 3-1 area.The results of GR inversion indicate that sandstone characteristics as strong wave trough amplitude and low wave impedance attribute.The sandbodys stretch in N-S or NW-SE directions.The channel sandbody developed in the northland of the study area while the mudstone of continental slope developed in the southland.The sand body distribution of deep water fan in different stage is described by sequence-lithofacies paleogeographic mapping and GR inversion,and the temporal and spatial distribution model of channel sand body of deep water fan have been established.The results are useful in predicting sand body of deep water fan reservoir.更多还原