| 摘要 |
An enhanced oil recovery process for subterranean reservoirs wherein there is injected into the reservoir a relatively large slug of a dilute aqueous alkali metal silicate solution. It is optional to follow the silicate solution with an aqueous drive fluid. In treating heterogeneous reservoirs, it is further optional, prior to injecting the large slug of silicate solution, to inject one or more small slugs of the silicate solution alternately with one or more small slugs of a dilute aqueous solution of an agent that reacts with the alkali metal silicate to form a gelatinous precipitate. In the latter instance a small spacer slug of water is injected between successive slugs of the reactant solutions to separate the reactants during injection. It is still another option to precede the injection of the large slug of dilute aqueous alkali metal silicate solution with the injection of a slug of an aqueous solution of an alkali metal or ammonium salt selected from the group consisting of chloride, bromide, iodide and nitrate salts and admixtures thereof.
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