If a gel-degrading fluid (e.g., acid, bleach, enzymes, oxidizers) is injected after the gel forms, worm holes will form through the gel for most practical injection rates.43 Since worm-holing phenomena scale the same as viscous fingering, the analogous arguments made above apply to worm-holing, as well as viscous fingering.43 In particular, in reservoirs with non-communicating layers, a degrading postflush will not reliably breakthrough a gel bank in low-permeability zones before that in high-permeability zones.