考虑剪切变稀和吸附滞留的聚合物驱相对渗透率研究

Considering Shear-thinning,Static Adsorption and Dynamic Retention on Polymer Flooding Relative Permeability

通过Blake-Kozeny方程推导了聚、油两相渗流时聚合物有效粘度计算公式,并通过兰格缪尔方程引入了相对渗透率下降因子。将有效粘度及渗透率下降因子代入广义达西公式获得了考虑剪切变稀和吸附滞留的稳态法聚合物驱相对渗透率计算公式。室内通过物理实验对比了新方法与传统稳态法聚合物驱相渗曲线区别,以及水驱和聚合物驱相渗曲线的区别。研究结果表明:与传统稳态法相比,受不可及体积和吸附滞留的影响,新方法计算的油相和聚合物相相对渗透率值均较低,其中油相相对渗透率主要受吸附滞留的影响,较传统稳态法下降了12%,聚合物相相对渗透率受不可及体积和吸附滞留的共同影响,较传统稳态法下降了44%。由于新方法不仅考虑了聚合物剪切变稀的非牛顿流体特性,还考虑了聚合物不可及体积和吸附滞留引起的渗透率下降,结果更为准确可靠。

Through Blake-Kozeny equation the effective viscosity of polymer was derived,and with Langmiur isotherm equation the effect of static adsorption and dynamic retention on oil / polymer relative permeability was considered by introducing relative permeability reduction ratio. With polymer effective viscosity,relative permeability and broader Darcy＇s law,the relative permeability of polymer flooding in steady state could be obtained by considering shear-thinning,static adsorption and dynamic retention effect. Then,laboratory experiments were conducted to compare the relative permeability of polymer flooding obtained by new method with that of old method and water flooding. The results showed that both oil phase and polymer phase relative permeabilities obtained by new method are much lower than old method due to the effect of inaccessible pore volume,static adsorption and dynamic retention. Because of static adsorption,oil phase relative permeability reduced by 12% compared with water flooding.In addition,polymer phase relative permeability reduced by 44% due to effect of inaccessible pore volume and dynamic retention. Therefore,the new method is more reliable by considering shear-thinning,static adsorption and dynamic retention.