Architectural Structure of channel sand bodies in meandering river and remaining oil tapping study-as on PI2a of South-Two area in Sanan field

摘要

According to the theory of reservoir architectural structure and sedimentology, applied the hierarchy analysis, pattern guidance and performance verification methods, taking the South-Two area for example, with the cores, logs and performance, we have done some quantitative research on the parameters of composite channel sand bodies, single point bar sand bodies and the lateral accretion bodies on point bars in South two area, built Three-dimensional model of point bars. Study shows that the point bar sand bodies in PI2a unit are meandering point bar sand bodies formed by the lateral accretion of distributary channels in coastal delta distributary plain. The space combination model of lateral accretion bodies is horizontal-obique type. The width of lateral accretion bodies is 38.5～54m, the average dip of lateral accretion layer is 9.5°, and separation of lateral accretion layer is about 15m. The features above shows the spatial distribution of the lateral accretion body on point bars. With the changes of seepage field and gravity, the influence to remaining oil of lateral accretion layer has been analyzed. Numerical simulation and performance showed that the main concentration of remaining oil is in the upper of the point bar lateral accretion body, proposed the principles and methods of horizontal wells in the point bar sand bodies to tapping potential remaining oil, which provide a theoretical guidance to domestic similar fine reservoir description and the remaining oil tapping.