MOBILITY CONTROLLED CAUSTIC FLOODING PROCESS FOR RESERVOIRS CONTAINING DISSOLVED DIVALENT METAL CATIONS

摘要

Abstract of the DisclosureA process for recovering oil from subterraneanreservoirs having connate water containing dissolved divalentmetal cations in which small slugs of (1) aqueous alkali metalhydroxide solution, (2) a diluto aqueous alkaline alkali metalsilicate solution, and (3) a dilute aqueous solution of an agentthat reacts with the alkali metal silicate to form a gelatinousprecipitate are alternately injected into the reservoir throughone or more injection wells. A small slug of water is injectedbetween successive slugs of the reactant solutions to separatethe reactants during injection. Also, alkali metal carbonatecan be incorporated into the aqueous alkali metal hydroxidesolution, or aqueous alkali metal carbonate solution can beinjected immediately preceding the alkali metal hydroxidesolution.