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AssigneeUnion Oil Company of California
InventorsAmir M. Sarem, Russell C. Darr, Dale L. Elchlepp, Robert B. Spratt
Estimating the term…
A process for recovering petroleum from subterranean reservoirs where high salt content water is used in a secondary recovery process consisting of forming as the displacement fluid a dilute alkaline silicate solution utilizing the high salt content water and filtering the alkaline flooding solution to remove scale-forming alkali insoluble salts which include a substantial proportion of calcium and magnesium salts. The filtered solution is injected into the reservoir and this is followed by an injection of a slug of substantially neutral water. A dilute acid solution is utilized to contact and dissolve the alkaline insoluble salts which have been filtered from the alkaline solution and the thus formed solution which includes a substantial portion of soluble calcium and magnesium salts is injected into the reservoir for subsequent contact with the alkaline silicate solution. This contact results in the formation of precipitates which partially plug that portion of the reservoir in which the contact occurs and reduces the permeability thereof. The process is repeated a plurality of times until the desired amount of alkaline silicate solution has been injected into the reservoir whereupon untreated water can be injected as a drive fluid.
A process for recovering petroleum from a subterranean reservoir penetrated by an injection well and a production well spaced apart in the reservoir which comprises alternately injecting into the reservoir through the injection well for a selected time period a petroleum displacement fluid comprising a dilute alkaline aqueous solution of an alkali metal silicate and thereafter injecting for a selected time period a dilute aqueous precipitate-forming solution of a material that reacts with the alkali metal silicate to form a precipitate, said alkali metal silicate solution further containing alkaline insoluble, scale forming salts comprising cations which form insoluble silicates, the improvement comprising:
A process for recovering petroleum from a subterranean reservoir penetrated by one or more injection wells and one or more production wells spaced apart from said injection well, said process comprising the steps of:
Dependencies are inferred from the claim text.