黏弹性聚合物溶液微观波及效率分析

Analysis on microscopic sweep efficiency of viscoelastic polymer solution

为进一步了解黏弹性聚合物溶液的驱油机理,提高驱油效率,对黏弹性溶液的微观波及效率进行了分析研究。首先,在雷诺数为定值条件下,计算绘制黏弹性聚合物溶液的速度等值线图、第一法向应力等值线图、第二法向应力等值线图;然后,在不同雷诺数条件下,计算绘制微观波及效率随威森伯格数的变化情况。在此基础上,根据应力场中值为0的等值线在突扩流道凸角处伸展区域的不同,对微观波及效率的变化进行解释。研究结果表明,当应力场中有利于死油区内流体流动的应力区域向突扩孔道凸角的死油区扩张时,能够使更多的流体流动起来,在速度场上就表现为速度等值线向凸角伸展,进而增加微观波及效率。

The microscopic sweep efficiency of viscoelastic polymer fluid is studied to better understand its oil displacement mechanism and improve oil displacement efficiency. First,under the condition of constant Reynolds number( Re),the isograms of velocity,the first normal stress and the second normal stress are mapped and calculated; then under the condition of different Reynolds numbers,the change of microscopic sweep efficiency with Weissenberg numbers(We) is calculated and mapped. On the above basis,microscopic sweep efficiency is explained according to the differences of the extensional regions of 0-isoline in the stress field in the sudden expansion corner. The result shows that,when the stress region conductive to fluid flow expands towards the sudden expansion corner in the dead area within the stress field,more fluid can flow,and the velocity contour in the velocity field extends to the expansion corner,thus increased microscopic sweep efficiency.