Oil recovery process usable in high temperature formations containing high salinity water which may include high concentrations of polyvalent ions

Claim 1

A method for recovering petroleum from a subterranean, petroleum-containing, permeable formation penetrated by at least one injection well and at least one production well, both wells being in fluid communication with the formation, said formation containing water whose salinity is from about 50,000 to about 225,000 parts per million total dissolved solids, the formation temperature being greater than 175° F, comprising: a. introducing into the formation via the injection well an aqueous surfactant-containing fluid to displace petroleum toward the production well, said fluid comprising (1) from .05 to 5.0 percent by weight of an anionic organic sulfonate surfactant having an average equivalent weight not to exceed 360 selected from the group consisting of water-soluble sodium, potassium or ammonium salts of petroleum sulfonates, alkyl sulfonates having from 5 to 20 carbon atoms, alkylaryl sulfonates having from 5 to 14 carbon atoms in the alkyl chain and mixtures thereof; (2) from .05 to about 5.0 percent by weight of a phosphate ester surfactant with an average molecular weight not to exceed about 1,000 having the following formula: ##STR2## wherein R is an alkyl or alkylaryl radical having from 12 to 24 carbon atoms, m is a number from 1 to 20, x and y are 1 or 2 and the sum of x and y is 3, and R' is hydrogen, sodium, potassium, lithium or ammonium; (3) said surfactant fluid salinity being at least 50,000 parts per million total dissolved solids; and b. recovering petroleum displaced by the surfactant fluid from the formation via the production well.

Claim 2

A method for recovering petroleum from a subterranean, petroleum-containing, permeable formation penetrated by at least one injection well and at least one production well, both wells being in fluid communication with the formation, said formation containing water whose salinity is from about 50,000 to about 225,000 parts per million total dissolved solids, the formation temperature being greater than 175° F, comprising: a. introducing into the formation via the injection well an aqueous surfactant-containing fluid to displace petroleum toward the production well, said fluid comprising (1) from .05 to 5.0 percent by weight of an anionic organic sulfonate surfactant having an average equivalent weight not to exceed 360 selected from the group consisting of water-soluble sodium, potassium or ammonium salts of petroleum sulfonates, alkyl sulfonates having from 5 to 20 carbon atoms, alkylaryl sulfonates having from 5 to 14 carbon atoms in the alkyl chain and mixtures thereof; (2) from .05 to about 5.0 percent by weight of a phosphate ester surfactant with an average molecular weight not to exceed about 1,000 having the following formula: ##STR2## wherein R is an alkyl or alkylaryl radical having from 12 to 24 carbon atoms, m is a number from 1 to 20, x and y are 1 or 2 and the sum of x and y is 3, and R' is hydrogen, sodium, potassium, lithium or ammonium; (3) said surfactant fluid salinity being at least 50,000 parts per million total dissolved solids; and b. recovering petroleum displaced by the surfactant fluid from the formation via the production well.

Claim 6

A method for recovering petroleum from a subterranean, permeable, petroleum-containing formation penetrated by at least one injection well and at least one production well, both wells being in fluid communication with the formation, said formation containing water whose salinity is from about 100,000 to 225,000 parts per million total dissolved solids, the formation temperature being greater than 145° F, comprising: a. introducing into the formation via the injection well an aqueous, surfactant-containing fluid to displace petroleum toward the production well, said fluid comprising (1) from 0.05 to 5.0 percent by weight of and anionic organic sulfonate surfactant having an average equivalent weight not to exceed 360 selected from the group consisting of water-soluble sodium, potassium or ammonium salts of petroleum sulfonates, alkyl sulfonates having from 5 to 20 carbon atoms, alkylaryl sulfonates having from 5 to 14 carbon atoms in the alkyl chain and mixtures thereof; (2) from .05 to 5.0 percent by weight of a phosphate ester surfactant with an average molecular weight not to exceed about 1,000 having the following formula: pg,26 ##STR3## wherein R is an alkyl or alkylaryl radical having from 12 to 24 carbon atoms, m is a number from 1 to 20, x and y are 1 or 2 and the sum of x and y is 3, and R' is hydrogen, sodium, potassium, lithium or ammonium; (3) said surfactant fluid salinity being at least 100,000 parts per million total dissolved solids; and b. recovering petroleum displaced by the surfactant fluid from the formation via the production well.

Claim 7

A method for recovering petroleum from a subterranean, permeable, petroleum-containing formation penetrated by at least one injection well and at least one production well, both wells being in fluid communication with the formation, said formation containing water whose salinity is from about 100,000 to 225,000 parts per million total dissolved solids, the formation temperature being greater than 145° F, comprising: a. introducing into the formation via the injection well an aqueous, surfactant-containing fluid to displace petroleum toward the production well, said fluid comprising (1) from 0.05 to 5.0 percent by weight of and anionic organic sulfonate surfactant having an average equivalent weight not to exceed 360 selected from the group consisting of water-soluble sodium, potassium or ammonium salts of petroleum sulfonates, alkyl sulfonates having from 5 to 20 carbon atoms, alkylaryl sulfonates having from 5 to 14 carbon atoms in the alkyl chain and mixtures thereof; (2) from .05 to 5.0 percent by weight of a phosphate ester surfactant with an average molecular weight not to exceed about 1,000 having the following formula: pg,26 ##STR3## wherein R is an alkyl or alkylaryl radical having from 12 to 24 carbon atoms, m is a number from 1 to 20, x and y are 1 or 2 and the sum of x and y is 3, and R' is hydrogen, sodium, potassium, lithium or ammonium; (3) said surfactant fluid salinity being at least 100,000 parts per million total dissolved solids; and b. recovering petroleum displaced by the surfactant fluid from the formation via the production well.

Claim 11

A method for recovering petroleum from a subterranean, petroleum-containing, permeable formation penetrated by at least one injection well and at least one production well, both wells being in fluid communication with the formation, said formation containing water whose salinity is from about 150,000 to 225,000 parts per million total dissolved solids, the formation temperature being greater than 115° F, comprising: a. introducing into the formation via the injection well an aqueous surfactant-containing fluid to displace petroleum toward the production well, said fluid comprising: (1) from about .05 to about 5.0 percent by weight an anionic organic sulfonate surfactant having an average equivalent weight not to exceed 360 selected from the group consisting of water-soluble sodium, potassium or ammonium salts of petroleum sulfonates, alkyl sulfonates having from 5 to 20 carbon atoms, alkylaryl sulfonates having from 5 to 14 carbon atoms in the alkyl chain and mixtures thereof; and (2) from about .05 to about 5.0 percent by weight of a phosphate ester surfactant with an average molecular weight not to exceed about 1,000 having the following formula: ##STR4## wherein R is an alkyl or alkylaryl radical having from 12 to 24 carbon atoms, m is a number from 1 to 20, x and y are 1 or 2 and the sum of x and y is 3, and R' is hydrogen, sodium, potassium, lithium or ammonium; (3) said surfactant fluid salinity being at least 150,000 parts per million total dissolved solids; and b. recovering petroleum displaced by the surfactant fluid from the formation via the production well.

Claim 12

A method for recovering petroleum from a subterranean, petroleum-containing, permeable formation penetrated by at least one injection well and at least one production well, both wells being in fluid communication with the formation, said formation containing water whose salinity is from about 150,000 to 225,000 parts per million total dissolved solids, the formation temperature being greater than 115° F, comprising: a. introducing into the formation via the injection well an aqueous surfactant-containing fluid to displace petroleum toward the production well, said fluid comprising: (1) from about .05 to about 5.0 percent by weight an anionic organic sulfonate surfactant having an average equivalent weight not to exceed 360 selected from the group consisting of water-soluble sodium, potassium or ammonium salts of petroleum sulfonates, alkyl sulfonates having from 5 to 20 carbon atoms, alkylaryl sulfonates having from 5 to 14 carbon atoms in the alkyl chain and mixtures thereof; and (2) from about .05 to about 5.0 percent by weight of a phosphate ester surfactant with an average molecular weight not to exceed about 1,000 having the following formula: ##STR4## wherein R is an alkyl or alkylaryl radical having from 12 to 24 carbon atoms, m is a number from 1 to 20, x and y are 1 or 2 and the sum of x and y is 3, and R' is hydrogen, sodium, potassium, lithium or ammonium; (3) said surfactant fluid salinity being at least 150,000 parts per million total dissolved solids; and b. recovering petroleum displaced by the surfactant fluid from the formation via the production well.