Experimental Investigations of Heterogeneous Effect on Supercritical Pressure CO_2 and Water Flow in Sintered Porous Media

摘要

Experimental studies about CO_2-water displacement are necessary to understand the detailed flow process after supercritical CO_2 was injected into the deep saline aquifers. Spatial distribution of CO_2 at steady state is strongly correlated to the variation of porosity and permeability. When the CO_2 injected underground, the real structure of the storage sites are all more like heterogeneous structure. Therefore, it is necessary to investigate the heterogeneous effect on two phase flow in the porous media. MRI technique was used to visualize directly the distribution of the supercritical CO_2 injected into porous rocks containing water and to estimate directly the effect of viscosity, buoyancy, and capillary pressure on CO_2 migration. This article adapted experimental method to research the particular effects of the heterogeneous effect to the CO_2 displacement process during the CO_2 geological storage. The experiments can provide the saturation distribution of water and the relaxation time under the different ratio injection. Experimental results show that the heterogeneity influences the two phase flow in the porous media significant. When the supercritical pressure CO_2 was injected into the porous media with water, the supercritical pressure CO_2 would invade the big pores first and chose the easy way to displace the water. The heterogeneous will affect the irreducible water saturation and then the relative permeability curve. It means that when the field simulation is built, the heterogeneous effect should be considered.