聚合物驱相对渗透率曲线实验研究

相对渗透率曲线反映油藏岩石中多相流体的渗流和分布规律。在聚合物溶液流经多孔介质的地下流变性实验研究基础上,获得了聚合物溶液有效粘度与分流量和相饱和度之间的关系式。解决了聚合物吸附/滞留及非牛顿流效应对相对渗透率曲线的影响,从而建立并改进了稳定流法测定聚合物驱相对渗透率曲线的实验技术和方法。利用稳定流法实验技术,成功地测得了70℃高温油藏条件下的油/聚合物溶液体系的相对渗透率曲线和注聚合物段塞后的油/水体系的相对渗透率曲线,并确定了适当的相对渗透率曲线方程。讨论了聚合物驱相对渗透率曲线的特征,分析了水相中自由聚合物分子和岩石中吸附滞留的聚合物分子对相对渗透率曲线的影响,真实地反映了聚合物驱过程中的多相渗流规律,揭示了聚合物驱油机理。为聚合物驱的数值模拟、动态预测和效果评价提供了重要参数和基础依据。

AN EXPERIMENTAL STUDY ON RELATIVE PERMEABILITY CURVES OF POLYMER FLOODING

Relative permeability curves reflects the law of multiphase flow and distribution in reservior rock. According to experimental study on in-situ rheology of polymer solutions through porous media, an effective viscosity dependence of polymer solutoion upon phase saturation and fractional flow were obtained, in which the adverse influence of polymer adsorption/retention and non-Newtonian effects were eliminated. Therefore, a steady-state flow technique was established and modified for testing relative permeability curves of polymer flooding. At high reservoir temperature of 70℃, the relative permeability curves were successfully measured for both polymer/oil system and water/oil system after polymer slug by using the steady-state flow method.Suitable empirical equations were adopted for both curves. Then, the relative permeability behavior for polymer flooding was discussed and, effects of polymer molecules retained in rocks and free in aqueous phase were also analysed, thus revealing the law of multiphase flow and oil displacement mechanisms during polymer flooding.Consequently, the basic and important parameters were provided for numerical simulation, pcrformance prediction and effectiveness evaluation of polymer flooding.