基准面旋回对储层宏观非均质性的控制——以胡状集油田沙三中6—8油层组为例

储层层间非均质性与沉积微相和砂体发育规律关系密切,明显受控于基准面升降造成的可容空间变化和沉积物通量大小.通过对胡状集油田沙三中6—8油层组基准面旋回的识别、划分与对比,建立了该区高分辨率层序地层格架,采用砂岩分层系数、分布密度和隔层密度、频率等参数描述了各中期旋回储层层间非均质性变化,认为储层宏观非均质性受控于基准面的旋回变化,长期基准面上升的早期和下降的晚期形成的中期旋回,储层非均质性弱,长期基准面旋回由上升到下降的转换时期储层非均质性强.

Controls of base-level cycles on the macroscopic heterogeneity of reservoir: taking the sixth to the eighth units in the middle of Es3 of Huzhuangji Oilfield as an example

The macroscopic heterogeneity of reservoir is closely related to its sedimentary microfacies and the extent of sandstone development, and it is obviously controlled by the variation of accommodation caused by base-levels rising or subsiding and the alimentation of sediment. The high-resolution sequence stratigraphic framework of the studied area is set up by the identification, division and contrast of the base-level cycles. The interzonal heterogeneities of the middle-term cycles are described by means of the parameters such as the stratification coefficients and the distribution density of the sandbodies, and the density and the frequency of the in-erbeds, etc. It is held that the macroscopic heterogeneity of reservoir is controlled by the base-level cycles: the reservoir heterogeneity of the middle-term cycles formed in the earlier stage of base-level rising or the latter stage of base-level subsiding in the long-term cycle is weaker, and that formed in the conversion stage from the base-level rising to the base-level subsiding in the long-term cycle is stronger.