摘要
对于一定的油藏体系,聚合物驱在宏观压力梯度及界面张力不变的情况下,溶液的弹性越大,驱油效率越高,弹性是聚合物驱提高驱油效率的主要原因.测试相同相对分子质量梳形聚合物与普通聚合物溶液的流变性及黏弹性变化规律,提出利用第一法向应力差与剪切速率曲线的斜率定量表征溶液弹性的方法;在人造均质岩心上进行驱替实验,研究梳形聚合物溶液的黏弹性对驱油效率的影响.结果表明,梳形聚合物溶液具有更好的增黏效果;溶液黏弹性及毛管数对驱油效率的影响规律与常规聚合物驱相同,黏弹性及毛管数对驱油效率的作用效果相当;对于不同种类的聚合物驱,驱油效率的提高为体系毛管数及聚合物溶液弹性共同作用的结果.
In a definite reservoir system, when the macro pressure gradient and viscosity of polymer solution stay constant, the higher the elasticity, the higher the displacement efficiency is, so the elasticity is a primary factor in enhancing oil recovery. The rheological properties and viscoelasticity of comb polymer and conventional polymer with the same molecular weight are tested contrastively, the slope of first normal stress difference vs. shear rate is used to quantitatively demonstrate the elasticity of different polymer solutions. And through lab experiments on homogeneous artificial cores, the effect of viscoelasticity of comb polymer on displacement efficiency was studied. The results show that comb polymer is better in increasing the viscosity of solution. The laws of viscoelasticity and capillary number on displacement efficiency are the same as those of conventional polymer flooding, and the effects of viscoelasticity and capillary number on De are nearly equal. For different kinds of polymer flooding, the increase in displacement efficiency is the result of increasing the capillary number and the viscoealsticity of flooding fluid together. This result has a crucial significance in consummating the mechanism research of polymer flooding.
出处
《大庆石油学院学报》
CAS
北大核心
2008年第4期61-65,136,共5页
Journal of Daqing Petroleum Institute
基金
国家重点基础研究发展规划项目(973项目)资助(2005CB221300)
关键词
梳形聚合物
黏弹性
微观力
驱油效率
comb polymer
viscoelasticity
micro force
displacement efficiency
