聚合物驱相对渗透率曲线影响因素研究

聚合物驱相对渗透率曲线是描述多孔介质中多相渗流动态及油田聚驱开发指标计算和预测的重要基础资料。文章通过大量的非稳态法聚合物驱相对渗透率曲线测定实验,研究了岩心润湿性、渗透率和聚合物溶液粘弹性对聚合物驱相对渗透率曲线形状和特征的影响。结果表明,与亲油岩心相比,亲水岩心相对渗透率曲线上同一含水饱和度时聚合物相相对渗透率偏低,曲线右端点和等渗点都向右偏移,驱油效率较高;随着岩心渗透率的增加,相对渗透率曲线等渗点右移,两相流跨度增大,残余油饱和度变小,最终采出程度增加,含水上升率变低;与相同粘度的甘油驱对比,聚合物驱相对渗透率曲线的右端点明显右移,说明聚合物溶液的弹性可降低残余油饱和度,提高了微观驱油效率。

Research on influence factors of relative permeability curve in polymer flooding

The relative permeability curve in polymer flooding is the important basis to describe multiphase flow behavior in porous medium and to forecast development indicators. By using methods of unsteady state to determine the relative permeability curve, the thesis researches on influence of wet ability in core, permeability and viscoelasticity of polymer solution to the shape and characteristic of the relative permeability curve in polymer flooding. The results show that, to compare with the hydrophobic core, the relative permeability of the hydrophilic core is lower at the same water saturation. When the right end point and equal - permeability point on the curve are both moving to the right and the displacement efficiency is improved. With the permeability increasing, equal -permeability point moves to the right, oil water span enhances, residual oil saturation reduces. Thus, final recovery percent enhanced, water cut reduced. Comparing to glycerin flooding with the same viscosity, the right end point moves to the right on the relative permeability curve apparently, which can illustrate elasticity of polymer solution can make residual oil saturation reduced, and make micro efficiency of oil displacement enhanced.