石油学报 ›› 2011, Vol. 32 ›› Issue (5): 852-856.DOI: 10.7623/syxb201105017

• 油田开发 • 上一篇    下一篇

聚合物溶液黏弹性驱油微观机理

白玉湖 1,2  张贤松 1,2   

  1. 1海洋石油高效开发国家重点实验室  北京  100027; 2中海油研究总院  北京  100027
  • 收稿日期:2010-12-09 修回日期:2011-05-27 出版日期:2011-09-25 发布日期:2011-11-28
  • 通讯作者: 白玉湖
  • 作者简介:白玉湖,男,1976年8月生,2006获中国科学院力学研究所流体力学专业博士学位,现在中海油研究总院从事天然气水合物、化学驱等多相渗流方面的研究工作。
  • 基金资助:

    国家重点基础研究发展规划(973)项目(2010CB735505)资助。

The microscopic mechanism of oil displacement by viscoelastic polymer solution flooding

BAI Yuhu 1,2  ZHANG Xiansong 1,2   

  • Received:2010-12-09 Revised:2011-05-27 Online:2011-09-25 Published:2011-11-28

摘要:

采用力学分析方法,针对被毛管力束缚在孔喉处的残余油,突扩孔隙空间的残余油以及盲端残余油,理论上分析了聚合物溶液黏弹性驱油微观机理,分别得到了聚合物溶液黏弹性作用下微观残余油动用增量表达式。当考虑黏弹性时,孔喉处可动油的临界半径要大于单考虑聚合物溶液黏性时的临界半径,这使得一部分原来不流动的孔喉残余油滴会发生流动,原来可动的油滴更容易动起来,提高了残余油动用程度。分析结果表明,单依靠聚合物溶液的黏性几乎不可能把盲端残余油驱替出来。当考虑聚合物溶液黏弹性的挤出胀大效应时,会进一步将突扩孔隙空间内、盲端残余油驱替出来。提出了表示毛管力和重力相对大小的无量纲量,当该无量纲量越大时,理论推导的突扩孔隙空间及盲端残余油动用量表达式就越准确。

关键词: 聚合物溶液, 黏弹性, 孔喉残余油, 盲端残余油, 无量纲量

Abstract:

The microscopic mechanism of oil displacement by viscoelastic polymer solution flooding was theoretically analyzed with a mechanical method in order to recover residual oils bound by capillary pressure in the pore throat, sudden-expanded pore space and dead-end. Microscopic increment expressions for the availability of residual oils in different pores under the viscoelasticity of polymer solutions were individually derived. The results showed that the critical radius of the pore throat for available residual oils with the presence of viscoelastic polymer solutions was greater than that with the mere presence of viscous polymer solutions, because the former could result in the partial flow of the previously immobile residual oil and the more facile flow of the previously mobile residual oil, consequently, more residual oils could be displaced in viscoelastic polymer solution flooding. Analytical results demonstrated that residual oils in the sudden-expanded pore space and dead-end could be hardly displaced when viscous polymer solution flooding was applied alone, however, they could be partially displaced under the effect of extruded swelling behavior caused by the viscoelasticity of polymer solutions. The dimensionless parameter denoting the relative dominance of gravity and capillary pressure was then suggested, i.e. the greater the dimensionless parameter, the more accurate the increment expression theoretically deduced for the availability of residual oils in the sudden-expanded pore space and dead-end.

Key words: polymer solution, viscoelasticity, residual oil in pore throat, residual oil in dead-end, dimensionless parameter