Carbon sequestration in saline aquifers involves displacing resident brine from the pore space by supercritical CO2 (scCO2). The displacement process is considered unstable due to the unfavorable viscosity ratio (logM = -5.21), respectively. Crossover from capillary to viscous fingering was observed for logCa = -5.91~-5.21, resulting in a large decrease in scCO2 saturation. The discontinuous-rate experimental results confirmed the decrease in nonwetting fluid saturation during crossover from capillary to viscous fingering predicted by numerical simulations by Lenormand et al. (1988).1 Capillary fingering was the only mechanism that dominates all injection rates in the continuous-rate experiment, and resulted in monotonic increase in scCO2 saturation.
Revised: July 24, 2014 |
Published: January 1, 2013
Citation
Wang Y., C. Zhang, N. Wei, M. Oostrom, T.W. Wietsma, X. Li, and A. Bonneville. 2013.Experimental study of crossover from capillary to viscous fingering for supercritical CO2 - water displacement in a homogeneous pore network.Environmental Science & Technology 47, no. 1:212-218.PNNL-SA-87244.doi:10.1021/es3014503