Horizontal ethanol floods in clean, uniform, and layered sand packs under confined conditions

Abstract

]. More broadly, the stability of flooding fronts is paramount to efficiently displacing the resident pore fluids from a variety of porous media: oil reservoirs, filter beds, fixed beds (regeneration), and aquifer media [Homsy, 1987]. The miscible displacement of pore water by the advancing cosolvent front is affected by the differences in liquid properties, the characteristics of the porous media, and the cosolvent injection rate. A common condition is cosolvent override due to the buoyancy of the cosolvent, and this situation may be exacerbated when the advancing front reaches a NAPL source zone, especially for the case of dense nonaqueous phase liquids (DNAPLs). It is therefore important to understand the factors governing the stability of advancing fronts in order to predict the "stabilized" angle of the front and the time (distance) required for the angle to stabilize if, in fact, the advancing front does stabilize.Flow visualization studies of miscible flooding in quasi-twodimensional models (narrow width tanks, cells, and parallel plates) that allow for gravity-induced behavior under confined

Pore Water Characteristics Following a Release of Neat Ethanol onto Pre‐existing NAPL

“…As the released ethanol encountered the source zone, residual NAPL in the ethanol path was quickly dissolved and removed by the advancing ethanol front (Figure 3b). The bulk fuel (EtOH + dissolved NAPL) then moved downgradient from the source in the capillary zone with a wedge-shaped leading edge similar to that described in previous capillary zone surface-tension driven flow (Henry and Smith 2002) and ethanol flushing (Jawitz et al 1998;Grubb and Sitar 1999) studies.…”

Interphase mass transfer between fluids in subsurface formations: A review

“…In case of remediation of LNAPLs with densities higher than ethanol (e.g., toluene, benzene) the stratification and its negative effect on recovery can be overcome with the use of water ethanol mixtures which would decrease the density contrast that leads to stratification [210]. Grubb and Sitar [211,212] showed the occurrence of stratification when pure ethanol was flushed through DNAPL source zone.…”

Viscous and gravitational contributions to mixing during vertical brine transport in water‐saturated porous media

“…The reason for the dramatically different results of the Slobod and Howlett [1964] data is not certain, although this is one of the few data sets that utilized organic solvents to manipulate density and viscosity rather than using aqueous brines. Grubb and Sitar [1999] identify the importance of the nonmonotonic behavior of viscosity with alcohol concentration during cosolvent flooding for NAPL removal. For equal volume mixtures of some alcohols with water, the liquid viscosity can be 3 to 4 times that of the end-member viscosities, completely unlike the behavior of brines illustrated in Figure 2.…”