Inverted latex water flooding method

Claim 2

The process of claim 1 wherein the water-in-oil emulsion is comprised of: A. water ranging between 5 and 25 percent by weight; B. a water-soluble vinyl addition polymer having a concentration between 20 and 50 percent by weight; C. a hydrophobic liquid ranging between 5 and 35 percent by weight; and D. a water-in-oil emulsifying agent having a concentration between 0.1 and 30 percent by weight.

Claim 3

The process of claim 1 wherein the concentration of the water-soluble vinyl addition polymer in the polymeric latex is from 0.1 to 10 percent by weight.

Claim 4

The process of claim 1 wherein the polymer is an acrylamide-sodium acrylate copolymer.

Claim 5

The process of claim 5 wherein the weight ratio of acrylamide to sodium acrylate is 65:35.

Claim 6

The process of claim 1 wherein the polymer is polyacrylamide.

Claim 7

The process of claim 1 wherein the polymer is an acrylamide-methacrylic acid copolymer.

Claim 8

The process of claim 1 wherein the polymer is an acrylamide-sodium acrylate copolymer wherein the acrylic acid component is from 0.8 to 70 percent by weight and the acrylamide component is from 30 to 99.2 percent by weight.

Claim 9

A process for recovering oil from a subterranean oil-bearing formation which comprises introducing a water-in-oil emulsion in the presence of a water-soluble surfactant into an input well penetrating said formation and forcing said water-in-oil emulsion through said formation toward at least one producing well penetrating said formation at a distance from said input well, said emulsion containing dispersed therein from 0.01 to 35 percent by weight of a finely-divided water-soluble vinyl addition polymer and which is capable of being inverted in water whereby the water-soluble vinyl addition polymer is released into the water as a solution.

Claim 10

A process for recovering oil from a subterranean oil-bearing formation which comprises the following steps: A. introducing a brine solution containing from 0.5 to 5.0 percent by weight of a surfactant into an input well which penetrates said formation; then; B. introducing a water-in-oil emulsion into said input well which penetrates said formation, and allowing the water-in-oil emulsion to be left static for from 5 to 72 hours; said emulsion containing dispersed therein from 0.01 to 35 percent by weight of a finely-divided water-soluble vinyl addition polymer and which is capable of being inverted in water whereby the water-soluble vinyl addition polymer is released into the water as a solution; and C. then forcing said solution through said formation toward at least one producing well penetrating said formation at a distance from said input well.

Claim 11

The process of claim 11 whereIn the water-in-oil emulsion is comprised of: A. water ranging between 0.01 and 25 percent by weight; B. a water-soluble vinyl addition polymer having a concentration between 0.1 and 35 percent by weight; C. a hydrophobic liquid ranging between 5 and 99 percent by weight; and D. a water-in-oil emulsifying agent having a concentration between 0.001 and 30 percent by weight.