This paper describes the development of a novel method of in-depth permeability modification in porous media using specific surfactant/alcohol blends. The unique features of this method come from (1) the development of permeability modification primarily resulting from component separation of injected blends, (2) in-depth penetration of formations without premature injectivity loss, (3) the capability to propagate the permeability barrier farther through the porous media, and (4) ease of cleanup of the porous media. Laboratory studies showed that injecting these blends into porous media can reduce permeability significantly. The degree of permeability barrier penetration was controlled experimentally, and this barrier was propagated in-depth by subsequent injection of alcohol slugs. The permeability modification potential of these blends was comparable with that of conventional gelled-polymer treatments.