基于非均质大模型的特高含水油藏提高采收率方法研究

针对特高含水开发阶段水油比急剧上升、注水量大幅增加和现有技术适应性差等问题，采用非均质物理大模型探索了进一步提高水驱后和聚合物驱后特高含水油藏采收率的方法。研究了聚合物驱-井网调整、自聚集微球-活性剂驱等不同驱替阶段含油饱和度的分布特征，分析了试验过程中注入压力、采收率的变化情况。研究发现，采用井网调整改变流线方向结合聚合物驱扩大波及系数的方法，可使水驱后处于特高含水期油藏的采收率提高26.0%；自主研发的自聚集微球能够运移至油层深部封堵优势渗流通道，迫使后续驱油剂发生液流转向，进入剩余油潜力区，从而提高聚合物驱后特高含水期油藏的驱油效率，自聚集微球-活性剂体系的残余阻力系数是聚合物的1.5~1.6倍，可使聚合物驱后特高含水油藏的采收率提高5%以上。研究结果表明，水驱后特高含水期油藏可采取井网调整结合聚合物驱的方法提高其采收率，而对于高波及系数和高采出程度的聚合物驱后油藏，可采用微球活性剂相结合的深部调堵驱油方法提高其采收率。 

Research on Large Scale Heterogeneous Model Based EOR Methods for Ultra-High Water Cut Reservoirs

After water flooding and polymer flooding,problems can arise,such as a rapid increase of water-oil ratio and water consumption,and poor adaptability of current technologies in the development stage of ultra-high water cut fields.To better analyze the problems,a large-scale heterogeneous physical model was used to explore the EOR methods for the high ultra-high water cut reservoirs after water flooding and polymer flooding.The distribution characteristics of oil saturation in different flooding stages,such as polymer flooding-well pattern adjustment and self-aggregating microsphere-surfactant flooding,were studied and the changes of injection pressure and recovery factor during the test were analyzed.Studies suggested that a combination of streamline direction alteration by well pattern adjustment and sweep coefficient expansion with polymer flooding can be used to increase the recovery ratio of ultra-high water cut reservoirs by 26.0% after water flooding.The new modified self-aggregating microspheres can be transported to the deep reservoir to block the dominant seepage channels and to divert the subsequent oil displacing agent into the remaining oil potential area,hence enhancing oil displacement efficiency of ultra-high water cut reservoirs after polymer flooding.The residual drag coefficient of microsphere-surfactant system is 1.5-1.6 times of that of the polymer,and the recovery ratio after polymer flooding can be further increased by 5% or more.The results showed that the method of well pattern adjustment combined with polymer flooding is suitable for ultra-high water cut reservoirs after water flooding,and the combination of microsphere-surfactant and deep adjustment/plugging oil displacement can be used in polymer flooded reservoirs with high sweep coefficient and high recovery degree.