Method of reducing permeability in subterranean formation by use of alkali metal silicate foam

摘要

A method of reducing the permeability of an area of a subterranean formation is disclosed. An alkali metal silicate foam is produced by injecting into the formation a solution of alkali metal silicate and a chemical surfactant, and a non-condensible gas. The foam hardens into a substantially impermeable solid. The foam may be used to reduce permeability in areas of the formation which have been steam swept during steam stimulation cycles. Thus, subsequent steam stimulation cycles will be directed to uncontacted areas of the formation.