The Society of Rheology 89th Annual Meeting

October 8-12, 2017 - Denver, Colorado


Emulsions, Foams, and Interfacial Rheology

Effects of elastic flow instabilities on oil displacement in regular and irregular porous networks

October 9, 2017 (Monday) 11:30

Track 1 / Crystal A

(Click on name to view author profile)

  1. Sinha, Indranil (Texas Tech, Mechanical Engineering)
  2. Narayan, Shweta (University of Minnesota, Mechanical Engineering)
  3. Shi, Xueda (Texas Tech, Mechanical Engineering)
  4. Dutcher, Cari (University of Minnesota, Mechanical Engineering)
  5. Christopher, Gordon F. (Texas Tech, Mechanical Engineering)

(in printed abstract book)
Indranil Sinha1, Shweta Narayan2, Xueda Shi1, Cari Dutcher2, and Gordon F. Christopher1
1Mechanical Engineering, Texas Tech, Lubbock, TX 79409; 2Mechanical Engineering, University of Minnesota, Minneapolis, MN 55455

Sinha, Indranil

Polymer flooding is an enhanced oil recovery technique used after both primary and secondary recovery have been exhausted and can often produce 30-60% of a wells output. Although, initially it was believed increased viscosity was the mechanism of enhancement, recent studies of porous elastic flows have indicated that displacement is improved by the changes to flow patterns caused by instabilities.

In this work, we demonstrate oil displacement by polymer flooding is improved in comparison to Newtonian fluid due to flow patterns caused by elastic instabilities at critical Mach numbers, and not due to increased excess pressure drops. This primarily appears due to the ability of the elastic instabilities to overcome capillary pressure in locally trapped oil bridges between solid surfaces and to better penetrate trapped regions of oil through normal velocities. Furthermore, we find that the nature of the porous network has a pronounced effect on the efficacy of this mechanism. Using square packed cylinder grids, hexagonally packed cylinder grids, and mock sandstone geometries, it is observed that polymer flooding is benefited by non-regular porous networks, which allow the normal velocities created by instabilities to better displace flow. Finally, we observe the effect of fractures in the geometries on the ability of polymer flooding to displace oil. Above critical Mach numbers, polymer flooding is able to better penetrate denser networks than Newtonian fluids due to the normal flow velocities that develop.