微孔道聚合物溶液驱替残余油变形研究

Deformation Study of Polymer Solution Displacement Residual Oil in Micro Channel

为了进一步研究聚合物溶液驱替岩心微孔道中残余油的流动规律,探索驱替液弹性对残余油变形的影响规律,进一步研究黏弹性驱替液对岩心微孔道中残余油的驱替机理,运用非牛顿流体力学理论建立流动方程,采用数值计算方法求解残余油的变形。计算结果表明:随着We数的增大,残余油的前进角逐渐增大,后退角逐渐减小,变形指数逐渐增大,起始阶段变形指数按照线性规律增加,后成抛物线型增加。较高的浓度或分子量的聚合物溶液都会显著地增加其弹性,使得残余油产生显著的变形,更有利于残余油的运移或剥离,从而验证了数值计算所得的结果——弹性可增大残余油的变形,提高驱油效率,进一步提高原油采收率,这就是聚驱提高原油采收率的水动力学机理。

In order to further study flow law of polymer solution displacement residual oil in the rock micro channel, explore influence law of the elasticity of displacing fluid on the deformation of residual oil, further study displacement mechanism of visco-elastic displacing fluid acting residual oil in the micro channel, the flow equation is established by using non-newtonian fluid mechanics theory, numerical methods is used to calculate the deformation of residual oil. The results shows that： With the increase of We, advancing angle of residual oil increases gradually, receding angle decreases gradually, the deformation index increases gradually, the deformation index increases with linear law at the initial stage, then the deformation index increases parabolic. The higher the concentration or molecular weight of polymer solution can both significantly increase the elasticity of displacing fluid, residual oil will produce prominent deformation, which is more conducive to migration and splitting, and the calculation results can be verified-Elasticity can increase deformation, improve displacement oil efficiency, and enhance oil recovery further, which is the hydrodynamic mechanism to enhance oil recovery of polymer flooding.