聚合物驱油体系弹性对高黏稠油驱油效率的影响

Influence of the Elasticity of Polymer Flooding on the Displacement Efficiency of Heavy Oil

冯茹森 周 洋 郭拥军 曹 苗 胡 俊 薛新生

FENG Rusen ZHOU Yang GUO Yongjun CAO Miao HU Jun XUE Xinsheng

为了解聚合物驱油体系的弹性对高黏稠油驱油效率的影响， 建立了一套模拟层内均质性的平板夹砂可视驱油实验装置， 提出了一种新的量化评价驱油效率的方法—灰度法， 研究了部分水解聚丙烯酰胺（HPAM）和疏水缔合聚丙烯酰胺 （HAWSP-2） 的弹性及其对稠油驱油效率的影响。结果表明： 由于疏水缔合作用的存在， 在低剪切速率下 HAWSP-2的抗剪切性好于 HPAM； 剪切黏度均为 100 mPa· s的 HPAM和 HAWSP-2的流型指数、 第一法向应力差、 屈服应力和形变恢复率分别为 0.384、 20.60 Pa、 0.29 Pa、 35.67%和 0.204、 67.50 Pa、 1.25 Pa、 183.15%，HAWSP-2的弹性大于 HPAM； 驱油实验中， 随着驱替模拟稠油黏度的增加， HPAM和 HAWSP-2的驱油效率均逐渐降低， 但 HAWSP-2的驱油效率总是高于 HPAM； 驱替同黏度的模拟稠油时， 单位驱油效率增幅所对应的弹性参数变化幅度从大到小依次为： 形变恢复率>屈服应力>第一法向应力差>流型指数， 即变形-恢复能力、 屈服应力、 第一法向应力差和流型指数对驱油效率的贡献依次增大。聚合物弹性对稠油驱油效率的影响为正相关关系， 流型指数是决定聚合物弹性对驱油效率影响的主导因素。图6表3参12

In order to understand the effect of the elasticity of polymer flooding system on the displacement efficiency of heavy oil with high viscosity，a flat sand inclusion visual flooding experimental device，which was used to simulate reservoir homogeneity， was established. Grey value method，a new quantitative evaluation method of oil displacement efficiency，was proposed. The elasticity of two typical polyacrylamide polymer，partially hydrolyzed polyacrylamide（HPAM）and hydrophobically associating polyacrylamide（HAWSP-2），and its impact on the displacement efficiency of heavy oil were studied. The experimental results showed that the shear resistance effect of HAWSP-2 was better than that of HPAM at low shearing rate，which was due to the existence of hydrophobic association. The flow index，the first normal stress difference，yield stress and deformation recovery rate of HPAM and HAWSP-2 with 100 mPa·s was 0.384，20.60 Pa，0.29 Pa，35.67% and 0.204，67.50 Pa，1.25 Pa，183.15%， respectively，indicating the elasticity of HAWSP-2 was greater than that of HPAM. In flooding experiment，with increasing viscosity of heavy oil，the oil displacement efficiency of HPAM and HAWSP-2 both decreased. But the oil displacement efficiency of HAWSP-2 was higher than that of HPAM. When heavy oil with same viscosity was flooded，four elastic parameters were arranged according to their changes corresponding the increase of per oil displacement efficiency in following order: deformation recovery rate>yield stress>the first normal stress difference>flow index， that was to say， the contribution of deformation-resilience，yield stress，the first normal stress difference and flow index to oil displacement efficiency increased. The effect of polymer elasticity on heavy oil displacement efficiency was positive correlation，and the flow index was the dominant factor of the effect of polymer elasticity on oil displacement efficiency.

10.19346/j.cnki.1000-4092.2016.06.017