Gas/water flow in porous media in the presence of adsorbed polymer: Experimental study on non-darcy effects

The objective of this paper is to report some experimental investigations on the effect of polymer adsorption on gas/water flow in non-Darcy regimes in homogeneous porous media, in contrast to previously available analyses focused mainly on the Darcy regime. Our investigation concentrates on gas flow either at low mean pressure. when Klinkenberg effects (or gas slippage) must be considered. or at high flow rates, when inertial effects are significant. The experimental study reported here consists of water and nitrogen injections into various silicon carbide model granular packs having different permeabilities. Experiments are carried out at different water saturations before and after polymer adsorption over flow regimes ranging from slip flow to inertial flow. In good agreement with previous works, in the Darcy regime, we observe an increase in irreducible water saturation and a strong reduction in the relative permeability to water, while the relative permeability to 2as is slightly affected. At low mean pressure in the gas phase, the magnitude of the Klinkenberg effect is found to increase with water saturation in the absence of polymer, whereas for the same water saturation, the presence of an adsorbed polymer layer reduces this effect. In the inertial regime, a reduction of inertial effects is observed when gas is injected after polymer adsorption, taking into account water- saturation and permeability modifications. Experimental data are discussed according to hypotheses put forth to explain these effects. Consequences for practical use are also put under prospect.