驱替速度对不同类型油层驱油效果评价研究

Evaluation research of displacement rate on oil-displacing efficiency in different types of reservoirs

驱替速度是影响驱油效率的重要因素之一,针对不同油藏地质条件和水驱特征的差异,以渗流力学为基础,通过理论分析和室内水驱油物理模拟实验,研究了驱替速度对不同类型油层驱油效率的影响规律。结果表明,对于均质油层,驱替速度的增加,毛管数增加,驱油效率先快速上升,达到一定值后,呈缓慢上升的趋势;对于非均质油层,存在一个最佳的驱替速度区间,驱替速度过低,低渗透层的油不利于驱出,驱替速度过高形成无效水循环,降低了注水利用率,致使注水开发效果变差。

Displacement rate is one of the important factors that affect oil displacement efficiency, according to different geological conditions and water drive reservoir characteristics,on the basis of percolation mechanics, through the theoretical analysis and physical simulation experiment of water flooding, the influence law of displacement rate on oil-displacing efficiency in different types of reservoirs are studied. The research results indicate that, for homogeneous reservoir, with the increase of displacement rate, the capillary number will increase, also oil-displacing efficiency rises rapidly first, after reaching a certain value, rising slowing. For heterogeneous reservoir, there is an optimal displacement rate range, if displacement rate is too low, oil of low permeable formation is not easy to drive out, however, when displacement rate is too high, invalid water cycle is easily formed and reducing the utilization rate of water flooding.