oa Polymer Velocity Enhancement and Accumulation at Water Oil Interfaces

An important aspect in polymer flooding is the existence of inaccessible and excluded pore volume in the reservoir. This leads to velocity enhancement i.e. polymere move faster through the porous medium than the water in which they are dissolved. In the conventional description the velocity enhancement factor is taken to be constant. We derived new model equations based on a percolation model. It turns out that the velocity enhancement factor can be expressed in terms of relative permeabilities and is therefore saturation dependent. This results in an accumulation of polymers at the oil interface. We verified the the theoretical findings with two-phase polymer flow experiments. Our experimental results show indeed a considerable pile-up of polymers at the interface.