In-situ cementation for profile control
AssigneeMobil Oil Corporation
InventorsPaul Shu, Ricky C. Ng, Craig H. Phelps
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Abstract
A method and composition for controlling the profile of a formation where temperatures higher than 200.degree. F. are encountered. An aqueous solution of an organoammonium silicate, alkali metal or ammonium silicate is injected into a zone of higher permeability in a formation. Subsequently, a spacer volume of a water-immiscible organic solvent is directed into said zone. Afterwards, a water-miscible organic solvent containing an alkylpolysilicate is injected into the higher permeability zone. A silica cement is formed in-situ thereby substantially closing the higher permeability zone to fluid flow. Thereafter, a steam-flooding, water-flooding, carbon dioxide-flooding, or fire-flooding EOR operation is commenced in a lower permeability zone.
Claims29
A profile control method where a silica cement is formed in-situ sufficient to close off a higher permeability zone in a formation comprising:
- a) injecting an aqueous solution into a higher permeability zone which solution contains a silicate selected from a member of the group consisting of alkali metal silicate, organoammonium silicate, or ammonium silicate;
- b) injecting thereafter a spacer volume of a water-miscible organic solvent into said zone;
- and
- c) injecting afterwards an alkylpolysilicate contained in a water-miscible organic solvent in an amount sufficient to react with silicate solution of step a) contained in said zone thereby forming a silica cement sufficient to close said zone to fluid flow therethrough.
A profile control method where a silica cement is formed in-situ sufficient to close off a higher permeability zone in a formation comprising:
- a) injecting an aqueous solution into a higher permeability zone which solution contains a silicate selected from a member of the group consisting of alkali metal silicate, organoammonium silicate, or ammonium silicate;
- b) injecting thereafter a spacer volume of a water-miscible organic solvent into said zone;
- c) injecting afterwards an alkylpolysilicate contained in a water-miscible organic solvent in an amount sufficient to react with the silicate solution of step a) contained in said zone thereby forming a silica cement sufficient to close said zone to fluid flow therethrough;
- and
- d) initiating an enhanced oil recovery method in a zone of lesser permeability within said formation and removing hydrocarbonaceous fluids therefrom.
Dependencies are inferred from the claim text.