The Effect of Hydrate Formation on Gas Relative Permeability in Porous Media

Abstract

Variation in gas permeability in Wallace sandstone samples exposed to hydrate formation was experimentally studied. The experiments were performed in a core flooding system. The relative permeability of CO2 at residual water saturation was measured first at 20°C. Then the gas permeability measurements were repeated during hydrate formation at 3 and 4°C. Experimental results show that it was possible to form CO2 hydrate in Wallace sandstone cores at injection pressure above 290 psi at temperatures of 3 and 4°C. All experimental data show that hydrate formation significantly reduces the permeability of porous media. Also, the results show that the amount of hydrate formation depends on the water content in the porous media. The experimental data show that permeability reduction was almost the same at 3 and 4°C at the same water content, which means that small temperature changes have relatively a small impact on the amount of hydrate formation.