聚驱后油藏井网调整与深部调剖三维物理模拟实验

针对聚合物驱后油藏剩余油分布特点,提出了井网调整与深部调驱相结合的提高采收率方法。孤岛油田中一区Ng3注聚区为模型原型,以相似准则为理论基础,设计并制作了平面非均质三维物理模型;研制了具有自组装特性的聚合物微球,优选出由BS与AES复配而成适用于目标油藏的乳化剂体系;原始一注四采五点法井网注聚后采收率为34.1%,在进行驱替试验的同时,采用电阻率法测量了模型中含水饱和度分布;调整原始井网,对非均质油藏模型分别注入聚合物溶液和聚合物微球与乳化剂复合体系深部调驱2组实验。结果表明,2个方案均可以提高聚驱后油藏采收率,单一聚合物溶液提高6百分点,而聚合物微球与乳化剂复合体系可提高采收率16百分点。分析各驱替阶段剩余油分布情况,聚合物微球与乳化剂复合体系能够封堵高渗层,使后续驱替液转向进入两侧低渗区域。

Three-dimensional physical simulation of well pattern adjusting and deep profile control on heterogeneous reservoir after polymer flooding

According to the remaining oil distribution after polymer flooding,the enhanced oil recovery method of well pattern adjustment and deep profile control was proposed.Zhongyiqu Ng3 Block,Gudao Oilfield,was selected as prototype to design and make plain heterogeneity three-dimensional physical model.Polymer microspheres of self-assembly were prepared.The optimal selection of BS/AES compound emulsifier system is suitable for target oil field.The enhanced oil recovery of the original well pattern after polymer flooding is 34.1％.The distribution of water saturation is measured by electrical resistivity method.The original well pattern was adjusted that two wells located in low permeability zone are injection wells and three wells located in high permeability zone are oil producing well.One heterogeneity three-dimensional physical model was injected with polymer solution and the other was injected with polymer microspheres/emulsion liquid composite system.The results show that two schemes can improve recovery efficiency of post-polymer flooding oil reservoir.Single polymer solution can only enhance 6％ recovery,but polymer microspheres/emulsion liquid composite system can enhance 16％ recovery.Analyzing the distribution of remaining oil in different displacement stages,polymer microspheres/emulsion liquid composite system can plug high permeability zone and drive subsequent displacement liquid into low permeability zone.