杏六东三元复合驱对储层改造及驱替效率评价

摘要

为了确定特高含水阶段三元复合驱对储层的改造及其对剩余油的驱替效率,利用复合驱前后2个时期同一河道内2口检查井的储层物性及含油饱和度数据,基于岩性约束条件,定量化计算三元复合驱对储层孔渗条件的改造作用,并且对比计算不同岩性及相同岩性不同位置处的驱替效率.结果表明:特高含水阶段的三元复合驱对粉砂岩的改造程度高于细砂岩,改造后的细砂岩孔渗条件仍优于粉砂岩,且细砂岩底部的孔渗条件比顶部的差.驱替剂主要在细砂岩层段进行驱油,且驱替效率受重力因素的影响明显,造成层段底部的驱替效率高于顶部.驱替剂对剩余油的作用包括2种方式,一是在孔渗条件好的层段发生剩余油的排驱,二是在顶部孔渗条件差的层段发生剩余油的再次聚集.在复合驱之后的特高含水后期,仍存在一定的产能,可通过改善生产工艺进行剩余油挖潜.%In order to understand reservoir reconstruction and displacement efficiency after alkaline surfactant polymer (ASP) flooding at extra-high water cut development stage,an approach integrating reservoir physical properties and remaining oil saturation parameters from two coring wells before and after ASP flooding within the same distributary channel was utilized.Based on lithology constraint,the effect of ASP flooding on reservoir pore and permeability condition was quantitatively calculated and the displacement efficiency of different lithology section and different position were compared.The results show that this effect on siltstone is more pronounced than that of fine sandstone section,and the physical property of fine sandstone is still better than siltstone and its top position is better than its bottom position.ASP displacement agent mainly works on fine sandstone section,and the effect of gravity factor on displacement efficiency is obvious,causing the displacement efficiency of base position is better than other positions.The effect of ASP on remaining oil includes two kinds of modes,the remaining oil being expelled in the section with better physical property,the remaining oil being gathered again in the section with worse physical property.After ASP flooding,at late extra high water cut stage,a certain production capacity still exists and can be developed through improving production process.