Experimental and numerical study of residual CO2 trapping in porous sandstone

摘要

To understand the structural and residual CO2 trapping mechanism, we conducted laboratory experiments and 2-D fluid flow simulations. The results of elastic wave velocity measurements indicate that there are strong effects of injected CO2 volume on elastic wave velocities. We calculated CO2 saturation from changes of Vs and estimated the irreducible water saturation and residual CO2 saturation. We also discovered the strong effect of small-scale heterogeneity of pore structure on fluid behavior by 2-D fluid flow simulation. The simulation results indicated that the laminae restricted fluid flow and stored CO2 as the residual trapped CO2. These results indicate that the small-scale heterogeneity is important to forming residual trapped CO2.