H41C-1335
CO2 Migration in a Stratified Reservoir System under Sequestration Conditions

Thursday, 17 December 2015
Poster Hall (Moscone South)
Kue-Young Kim1, Junho Oh1, Weon Shik Han2, Eungyu Park3 and Jeong-Chan Kim1, (1)Korea Ist Geoscience & Min Res, Daejeon, South Korea, (2)University of Wisconsin Milwaukee, Milwaukee, WI, United States, (3)Kyungpook National University, Daegu, South Korea
Abstract:
Experimental and numerical studies are presented at two different sequestration conditions, the terrestrial and the deep-sea conditions, to elucidate possible vertical/horizontal CO2 movement in a stratified reservoir system. The CO2-flooding experiments revealed that once CO2 is injected into a storage formation, the vertical migration of CO2 is driven by combination of pressure gradient and buoyancy force. The buoyancy force was significant in our experimental conditions. The dimensionless CO2 migration rate at vertical core setting was 36% greater than that in horizontal setting under the terrestrial condition. Experiments under both reservoir conditions showed that the injected CO2 tended to find preferential flow path (low capillary entry pressure and high-k path) and bypass the unfavorable pathways leaving the low CO2 saturation in the low-k layers. The liquid CO2 intruded the low-k layers more than supercritical CO2. Multiphase flow simulations have shown that the presence of low-k layers plays a role in CO2 storage capacity though flow perpendicular to low-k layers will deteriorate the injectivity. The CO2 saturation increased logarithmically with the corresponding increase in permeability modification coefficient while it decreased with capillary entry pressure. The scaled CO2 flux showed the effect of heterogeneity was greater with high gravity number (Ngr) and decreased with small Ngr as the viscous force increased. The heterogeneity of the medium as well as Ngr caused the spatial variation of pressure, CO2 saturation and CO2 flux.