Retention phenomena in non-Newtonian fluids flow

The dispersion phenomenon of a polymer solution (scleroglucane) in a porous medium has been studied using radioactive techniques. Three different experiments were performed. In Experiment I a free tracer (I131Na no bounded) was dissolved into the polymer solution. In Experiment II the same tracer (I131Na) but now chemically bounded to the polymer macromolecules was injected in a similar medium also initially saturated with polymeric solution. In Experiment III the tracer was the same as in Experiment II but the medium was initially saturated with water. The comparison of the different results shows that two retention mechanisms are possible: the first is due to the adsorption process and the other to the moleculeʹs mechanical trapping. Additionally, an increase of the retention phenomena was observed when the injection flow rate increased.