Micellar flooding process for recovering oil from petroleum reservoirs

Claim 1

In the method for recovering petroleum from a subterranean reservoir in which a micellar solution is injected into the reservoir through an injection well in communication therewith, and thereafter an aqueous flooding medium is injected to drive the micellar solution towards one or more spaced production wells from which fluids are recovered, the improvement which comprises injecting into said reservoir prior to the injection of said micellar solution an aqueous alkaline alkali metal silicate pretreating solution having a M 2 O/SiO 2 molar ratio of between about 1 and 4, wherein M is an alkali metal atom.

Claim 8

A method for recovering petroleum from a subterranean reservoir penetrated by an injection well and at least one production well spaced apart in the reservoir, which comprises: injecting about 0.01 to 0.5 pore volume of an aqueous alkaline alkali metal silicate pretreating solution having a M 2 O/SiO 2 molar ratio of between about 1.5 and 2.5, wherein M is an alkali metal atom, and said solution containing less than about 5 weight percent of alkali metal silicate; next injecting 0.01 to 0.15 pore volume of a micellar solution; thereafter injecting an aqueous flooding medium to drive the micellar solution towards a spaced production well; and recovering petroleum from said production well.

Claim 9

A method for recovering petroleum from a subterranean reservoir penetrated by an injection well and at least one production well spaced apart in the reservoir, which comprises: injecting about 0.01 to 0.5 pore volume of an aqueous alkaline alkali metal silicate pretreating solution having a M 2 O/SiO 2 molar ratio of between about 1.5 and 2.5, wherein M is an alkali metal atom, and said solution containing less than about 5 weight percent of alkali metal silicate; next injecting 0.01 to 0.15 pore volume of a micellar solution; thereafter injecting an aqueous flooding medium to drive the micellar solution towards a spaced production well; and recovering petroleum from said production well.

Claim 18

A method for recovering petroleum from a subterranean reservoir penetrated by an injection well and a production well spaced apart in the reservoir, which comprises: injecting about 0.01 to 0.5 pore volume of an aqueous alkaline sodium or potassium silicate pretreating solution having a M 2 O/SiO 2 molar ratio of between about 1.5 and 2.5, wherein M is a sodium or potassium atom, and said solution containing about 0.1 to 3 weight percent of sodium or potassium silicate; injecting 0.01 to 0.15 pore volume of a soluble oil comprising a mixture of 30 to 90 volume percent of liquid hydrocarbon, 0.5 to 8 volume percent of an organic liquid stabilizing agent, 4 to 30 volume percent of a mixture of preferentially oil-soluble surface active alkyl aryl sulfonates and preferentially water-soluble surface active alkyl aryl sulfonates, and 0 to about 50 volume percent of water present in the form of a water-in-oil microemulsion, said sulfonates being present in the proportion of about 1 to 15 parts by weight of oil-soluble sulfonate per part of water-soluble sulfonate; thereafter injecting an aqueous flooding medium to drive the soluble oil towards said spaced production well, at least an initial portion of said aqueous flooding medium being increased in viscosity by the addition of a water-soluble polymer, and recovering petroleum from said well.

Claim 19

A method for recovering petroleum from a subterranean reservoir penetrated by an injection well and a production well spaced apart in the reservoir, which comprises: injecting about 0.01 to 0.5 pore volume of an aqueous alkaline sodium or potassium silicate pretreating solution having a M 2 O/SiO 2 molar ratio of between about 1.5 and 2.5, wherein M is a sodium or potassium atom, and said solution containing about 0.1 to 3 weight percent of sodium or potassium silicate; injecting 0.01 to 0.15 pore volume of a soluble oil comprising a mixture of 30 to 90 volume percent of liquid hydrocarbon, 0.5 to 8 volume percent of an organic liquid stabilizing agent, 4 to 30 volume percent of a mixture of preferentially oil-soluble surface active alkyl aryl sulfonates and preferentially water-soluble surface active alkyl aryl sulfonates, and 0 to about 50 volume percent of water present in the form of a water-in-oil microemulsion, said sulfonates being present in the proportion of about 1 to 15 parts by weight of oil-soluble sulfonate per part of water-soluble sulfonate; thereafter injecting an aqueous flooding medium to drive the soluble oil towards said spaced production well, at least an initial portion of said aqueous flooding medium being increased in viscosity by the addition of a water-soluble polymer, and recovering petroleum from said well.

Claim 21

A method for recovering petroleum from a subterranean reservoir penetrated by an injection well and at least one production well spaced apart in the reservoir, which comprises: injecting about 0.01 to 0.5 pore volume of an aqueous alkaline sodium or potassium silicate pretreating solution having a M 2 O/SiO 2 molar ratio of between about 1.5 and 2.5, wherein M is a sodium or potassium atom, and said solution containing about 0.1 to 3 weight percent of sodium or potassium silicate; injecting 0.005 to 0.05 pore volume of an oleaginous micellar solution comprising a mixture of 30 to 90 volume percent of liquid hydrocarbon, 0.5 to 8 volume percent of an organic liquid stabilizing agent, 4 to 30 volume percent of a mixture of preferentially oil-soluble surface active alkyl aryl sulfonates and preferentially water-soluble surface active alkyl aryl sulfonates, and 0 to about 50 volume percent of water, present in the form of a water-in-oil microemulsion, said sulfonates being present in the proportion of about 1 to 15 parts by weight of oil-soluble sulfonates per part of water-soluble sulfonates; injecting 0.005 to 0.05 pore volume of a water-external microemulsion comprising a mixture of 75 to 90 volume percent of water, not more than about 8 percent of an organic liquid stabilizing agent, 2 to 20 volume percent of a mixture of preferentially oil-soluble surface active alkyl aryl sulfonates and preferentially water-soluble surface active alkyl aryl sulfonates, and not more than about 25 volume percent of oil present in the form of an oil-in-water microemulsion, said sulfonates being present in the proportion of about 1 to 15 parts by weight of oil-soluble sulfonates per part of water-soluble sulfonates; thereafter injecting an aqueous flooding medium to drive the previously injected fluids towards said spaced production well, at least an initial portion of said aqueous flooding medium being increased in viscosity by the addition of a water-soluble polymer, and recovering petroleum from said well.

Claim 22

A method for recovering petroleum from a subterranean reservoir penetrated by an injection well and at least one production well spaced apart in the reservoir, which comprises: injecting about 0.01 to 0.5 pore volume of an aqueous alkaline sodium or potassium silicate pretreating solution having a M 2 O/SiO 2 molar ratio of between about 1.5 and 2.5, wherein M is a sodium or potassium atom, and said solution containing about 0.1 to 3 weight percent of sodium or potassium silicate; injecting 0.005 to 0.05 pore volume of an oleaginous micellar solution comprising a mixture of 30 to 90 volume percent of liquid hydrocarbon, 0.5 to 8 volume percent of an organic liquid stabilizing agent, 4 to 30 volume percent of a mixture of preferentially oil-soluble surface active alkyl aryl sulfonates and preferentially water-soluble surface active alkyl aryl sulfonates, and 0 to about 50 volume percent of water, present in the form of a water-in-oil microemulsion, said sulfonates being present in the proportion of about 1 to 15 parts by weight of oil-soluble sulfonates per part of water-soluble sulfonates; injecting 0.005 to 0.05 pore volume of a water-external microemulsion comprising a mixture of 75 to 90 volume percent of water, not more than about 8 percent of an organic liquid stabilizing agent, 2 to 20 volume percent of a mixture of preferentially oil-soluble surface active alkyl aryl sulfonates and preferentially water-soluble surface active alkyl aryl sulfonates, and not more than about 25 volume percent of oil present in the form of an oil-in-water microemulsion, said sulfonates being present in the proportion of about 1 to 15 parts by weight of oil-soluble sulfonates per part of water-soluble sulfonates; thereafter injecting an aqueous flooding medium to drive the previously injected fluids towards said spaced production well, at least an initial portion of said aqueous flooding medium being increased in viscosity by the addition of a water-soluble polymer, and recovering petroleum from said well.