古地貌对渤海石臼坨凸起古近系沉积体系的控制作用

渤海湾盆地石臼坨凸起沙一、二段所发育的扇三角洲储层,在沉积演化过程中由于古地貌特征的不同,造成储集砂体形态特征及分布规律的不同,储层认识困难。通过分析断裂活动对古地貌格局的控制作用进行古地貌恢复,研究不同地貌单元与沉积体系的匹配关系,阐明了古地貌对沉积体系发育类型和沉积特征的控制作用,揭示了扇三角洲的沉积过程。在此基础上结合地震属性分析技术,精细描述了各沉积期次扇体的展布特征,并对沉积演化过程中扇三角洲沉积体系发育的差异性进行了解析。最终明确了盆地边缘沟谷和古地形发育特征对物源的控制作用,形成了"大沟对大扇,小沟对小扇"的沉积模式指导依据;同时确定了斜坡带上扇三角洲的沉积规律和砂体分布的控制机理。

Controlling of Paleogeomorphology to Paleogene Sedimentary System of Shijiutuo Uplift in Bohai Basin

As a result of the sedimentary evolution ,the sand bodies and distribution of the fan delta reservoir developed in the first and second member of Shahejie Formation in Shijiutuo uplift are paleo ‐geomorphically different . The reservoir prediction is difficult . The authors carry out the paleo‐geomorphology reconstruction by analyzing the control action of the fault movement on the paleo‐geomorphic pattern , study the relationship between the paleo‐geomorphic unit and the sedimentary system ,explain the control of paleo‐geomorphology on sedimentary system ,and reveal the sedimentary process .On the above , seismic attributes and the distribution characteristics of the fan delta , the difference of fan delta sedimentary system development is analyzed .Finally ,the control action of the basin edge valleys and paleo‐geomorphology on provenance is figured out .A depositional model ,“large valleys correspond to large fans and small valleys correspond to small valleys ” ,is established .Also ,the depositional pattern of the fan delta located in slope zone and the control mechanism of sands distribution are determined .The method can predict a reservoir effectively in oilfield exploration and development stages .