Use of surfactant foam for recovery of petroleum

Claim 2

The process of claim 1 wherein the foam is produced at the surface and injected into the subterranean formation through said injection means.

Claim 3

The process of claim 1 wherein the micellar dispersion is comprised of hydrocarbon, water, and surfactant.

Claim 4

The process of claim 4 wherein the water-external micellar dispersion comprises from about 4 to 45 volume percent hydrocarbon, about 50 to 95 volume percent water, and from about 4 to 20 volume percent surfactant.

Claim 5

The process of claim 5 wherein the micellar dispersion contains from about 0.01 to 20 volume percent of cosurfactant.

Claim 6

The process of claim 5 wherein the micellar dispersion contains about 0.001 to about 5 percent electrolyte.

Claim 7

The process of claim 1 wherein the foam is displaced by injecting a fluid drive material into the formation.

Claim 8

The process of claim 8 wherein the drive material is a gas.

Claim 9

The process of claim 8 wherein the drive material is an aqueous medium.

Claim 10

The process of claim 8 wherein about 5 to 80 pore volume of a mobility buffer is injected after the foam, having a mobility about equal to or greater than said foam.

Claim 11

The process of claim 11 wherein the mobility buffer has a mobility about equal to or less than about that of the back portion of the foam.

Claim 12

A process for recovery of hydrocarbon from a hydrocarbon containing subterranean formation having at least one injection means in fluid communication with at least one producing means, the process comprising: a. injectig into the formation a water-external micellar dispersion comprising about 4 to about 45 percent hydrocarbon, about 50 to about 95 percent water, and at least about 4 percent surfactant, the percents based on volume, and, b. injecting a gas compatible with the micellar dispersion into the formation simultaneously with or subsequent to injection of said micellar dispersion so that when the gas and micellar dispersion come into intimate contact a foam is generated, thereafter, c. injecting into the formation about 5 to 80 percent pore volume of a mobility buffer, and d. injecting a drive material to displace the foam and mobility buffer toward the producing means and recovering hydrocarbon through said producing means.

Claim 13

The process of claim 13 wherein the mobility buffer comprises water and a mobility reducing agent.

Claim 14

The process of claim 13 wherein the drive material is water.

Claim 15

The process of claim 13 wherein the mobility of the front portion of the mobility buffer is about equal to or less than the mobility of the back portion of the foam.