Oil recovery method

Claim 1

The method defined in claim 1 wherein said aqueous polymer solution is injected in an amount sufficient to penetrate into the more permeable strata a distance of at least about 20 feet from the injection well.

Claim 4

A method for flooding a heterogeneous reservoir having strata or channels of relatively high permeability through which injected flooding media preferentially flow, which comprises: injecting an aqueous solution of a mobility reducing water-soluble polymer through an injection well in communication with said reservoir, said solution being injected in an amount sufficient to penetrate into the more permeable strata of the reservoir a distance of at least about 20 feet from the injection well; next injecting a liquid plugging agent that reacts in the reservoir to form a plugging material that at least partially plugs the more permeable strata adjacent to the injection well, said liquid plugging agent being injected in an amount sufficient to penetrate into the more permeable strata of the reservoirs a distance of not more than about 10 feet from the injection well; and thereafter injecting flooding media to displace oil towards one or more spaced production wells.

Claim 11

A method for reducing the permeability of a high permeability strata or channels in communication with a well, which comprises: injecting into said high permeability strata about 5 to 200 barrels per vertical foot of strata to be treated of an aqueous solution containing about 0.001 to 1 weight percent of a mobility reducing water-soluble polymer selected from the group consisting of relatively high molecular weight acrylic acid-acrylamide copolymer, acrylic acid-acrylamide-diacetone acrylamide terpolymer, partially hydrolyzed polyacrylamide, hydroxyethyl cellulose, carboxymethyl cellulose, polyacrylamide, polyoxyethylene, modified starch, heteropolysaccharide obtained by the fermentation of starch derived sugar, polyvinyl alcohol, polyvinyl pyrollidone and polystyrene sulfonate; and thereafter injecting into said strata about 1 to 10 barrels per vertical foot of strata to be treated of an aqueous sodium silicate solution containing a gelling agent selected from the group consisting of acid and acid forming compounds, water-soluble ammonium salts, lower aldehydes, aluminum salts, and alkali metal aluminates.

Claim 12

A method for flooding a heterogeneous reservoir having strata or channels of relatively high permeability through which injected flooding media preferentially flow, which comprises: injecting through an injection well and into said reservoir about 1 to 10 barrels of fresh water per vertical foot of reservoir to be treated; then injecting through said injection well an aqueous solution containing about 0.001 to 1 weight percent of a mobiLity reducing water-soluble polymer in an amount between about 5 and 200 barrels per vertical foot of reservoir to be treated sufficient to penetrate into the more permeable strata a distance of at least about 20 feet from the injection well; next injecting through said injection well an aqueous solution containing about 1 to 30 weight percent of sodium silicate and a gelling agent selected from the group consisting of acid and acid forming compounds, water-soluble ammonium salts, lower aldehydes, aluminum salts and alkali metal aluminates in an amount between about 1 and 10 barrels per vertical foot of formation to be treated sufficient to penetrate into the more permeable strata of the reservoir a distance of not more than about 10 feet from the injection well; next injecting through said injection well about 1 to 10 barrels of fresh water per vertical foot of reservoir to be treated; and thereafter injecting flooding media through said injection well to displace oil towards one or more spaced production wells.