【摘要】 运用高分辨率层序地层的短期基准面旋回原理 ,对发育于陕甘宁盆地城华地区长 3油层组缓坡带上的三角洲前缘的储集砂体进行细致分析 ,按成因将储层砂体详细划分为三大类 6种类型 ,而这几种类型砂体的成因明显受基准面升降、可容纳空间 (A)和沉积物补给量 (S)之间变化关系两方面的影响。在基准面上升过程中 ,A/S <1时 ,以截削式河道砂体为主 ,A/S >1时 ,则为完整式河道砂体 ;在基准面下降过程中 ,A/S <1时 ,以孤立式河口坝砂体为主 ,A/S >1时 ,则以叠加式河口坝和远砂坝砂体为主 ;在水下坡折带沉积区 ,则为复合式坝砂体。基准面升降过程中 ,短期基准面旋回的规律性变化 ,影响着不同成因砂体的分布 ,据此建立了坳陷型湖盆缓坡带三角洲前缘不同砂体类型的成因分布模式更多还原

【Abstract】 By using short term base level cycle theory of high resolution sequence stratigraphy, we delicately analyzed reservoir sandstones which deposited on the delta front gentle slope zone with Chang Ⅲ oil Formation in Chenghua area, Shanxi gansu ningxia basin. On the base of genetic, reservoir sandstones may be divided into three types of sandstones that consist of six subtypes. While these sandstones genetic are evidently influenced by the short term base level up and down changes and the relation of accompanied accommodations and sediment alimentations. In the course of base level rising, ① A/S<1, sandstone genetic type is mainly truncated distributary channel sandstone body. ② A/S>1, sandstone genetic type is mainly integrated distributary channel sandstone body. There is recombination bar genetic sandstone body at the underwater slope break zone. With the base level up and down changes, regular change of short term base level cycle influences the distribution of different genetic sandstone bodies. And distributional model of different genetic sandstones that deposit on different locals of delta front at gentle slope in depressed type lacustrine basin is built.更多还原