摘要
采用上随体Maxwell本构方程,描述油藏条件下以第一法向应力差为主要特征的聚合物溶液的流变性.利用有限体积法对黏弹性聚合物溶液在突扩孔道内的流动特征进行数值模拟.绘制了流函数和速度的等值线图.研究了黏弹性的变化对微观波及效率的影响.数值模拟结果表明,聚合物溶液的黏弹性是影响波及效率的主要因素.凹角处的流动区域随着弹性的增加在不断增大,因此滞留区域不断减小,微观波及效率不断增大.具有黏弹特性的聚合物溶液相比于纯黏性的牛顿流体更利于提高驱油效率.这一结论有助于驱油工业上聚合物溶液的设计和优选.
The upper-convected Maxwell （UCM） model was used to describe the rheological properties of polymers. A finite volume method （FVM） for the numerical solution of viscoelastic flows through an abrupt expansion channel is presented. Although there have been many successful numerical predictions of elastic fluid flows, the Weissenberg number （We） which stands for the elastic is low. With the FVM, stable solutions are found for high Weissenberg number （the elasticity levels up to We = 3.2）, further extending the range of previous similar simulations. The simulations reinforce the point that the FVM can be used as a viable alternative for the solution of viscoelastic problems. Through the results of numerical simulations, the contours of velocity and stream function are drawn and micro-scale sweep efficiency is calculated quantitatively. Numerical results show that the viscoelasticity of polymer solutions is the main factor influencing the sweep efficiency. With increasing elasticity, the flowing area in the dead end is enlarged significantly, thus the area with immobile zones becomes smaller, the microcosmic sweep efficiency increases. The visco-elastic nature of the displacing polymer fluids can in general improve the displacement efficiency in pores compared to using Newtonian fluids. This conclusion should be useful in selecting polymer fluids and designing polymer flooding operations.
出处
《高分子学报》
SCIE
CAS
CSCD
北大核心
2009年第6期520-524,共5页
Acta Polymerica Sinica
基金
国家自然科学基金重点项目(基金号0634020)资助项目
国家重点基础研究发展计划(973计划,项目号2005CB221300)
黑龙江省教育厅科学技术研究项目(项目号11521003)
黑龙江省研究生创新科研项目(项目号YJSCX2008-047HLJ)资助
