地下点坝砂体内部构型分析--以孤岛油田为例

用Miall层次界面分析法对孤岛油田52井组馆陶组Ng4^4砂层点坝砂体内部3，4级界面进行详细研究，并与Miall的6级层次界面相对应，定义4级界面为单一河道的顶底界面，构型要素为单一的点坝砂体；3级界面为点坝内部侧积体分界面，实际上是点坝砂体的侧积面，其限定的构型要素为点坝侧积体。还对单井进行了泥质界面划分及成因砂体分析，建立了点坝成因砂体单井模型，根据研究区开发动态特征，推论点坝砂体内部存在倾斜的泥质侧积层，并借助储层地质学基本理论，对侧积体规模、倾角进行了限定。在上述研究基础上建立了点坝侧积体的三维地质模型，数值模拟结果研究表明，点坝侧积层对剩余油分布具明显控制作用。

THE ARCHITECTURE ANALYSIS OF THE UNDERGROUND POINT BAR-TAKING GUDAO OILFIELD AS AN EXAMPLE

The third and fourth-order surfaces of point bar of 52 well groups in Gudao oil field were systemically analysed according to the theory of Miall hierarchy interfaces. Compared with Miall six-order surfaces, the top and bottom boundary surfaces of single channel were defined as the fourth-order and the architectural element was single point bar sandbody.The interfaces of the lateral accretion bodies were defined as the third-order and the architectural element was lateral accretion bodies.Architecture of single well was established after partitioning the interfaces of single well.The lateral accretion occurrd as mud was deduced from dynamic analysis.The scale and obliquity were demarcated in reference to the knowledge of reservoir geology.A 3-D model of point bar was proposeded through above research and the results of numerical simulation revealed that the lateral accretion mud could control the residual oil distribution effectively.