In-situ silica cementation for profile control during steam injection

A profile control method for closing a higher permeability zone of a formation of fluid flow, comprising:

• a) injecting into said zone an aqueous solution containing a member selected from the group consisting of an alkali metal hydroxide, ammonium hydroxide, or organoammonium hydroxide;
• b) injecting thereafter a spacer volume of a water-miscible organic solvent into said zone;
• c) injecting afterwards into said zone a water-miscible organic solvent containing an alkylpolysilicate in an amount sufficient to react with a member from step a) thereby forming a silica cement sufficient to close said zone to fluid flow;
• and
• d) initiating subsequently an enhanced oil recovery method in a lower permeability zone of a formation which method is a member selected from the group consisting of water-flooding, steam flooding, fire flooding, and carbon dioxide stimulation.