Difference between Steam-water and Air-water Relative Permeabilities in Fractures

The goal of this research has been to compare steamand air-water transport through fractured media and gain better understanding of the behaviors of relative permeability in fractures. Airwater (or nitrogen-water) relative permeabilities are often used for geothermal reservoir simulations while steam-water relative permeabilities in fractures are rarely measured owing to difficulties and complexities of steam-water experiments. A novel and accurate methodology was developed to capture the unstable nature of the steam-water flow in a smooth-walled fracture. Repeatable results were obtained and show that steam-water relative permeabilities are different from nitrogen-water relative permeabilities. The average steam-water relative permeabilities show less phase interference. Also, comparing with previous research into airwater relative permeabilities in fractures, both average steamand nitrogen-water relative permeabilities were seen to behave closer to the X-curve.