Claims Analysis
Total Claims: 38
Claim 1
Independent Claim
247 words
A method for recovering petroleum from a subterranean, permeable, petroleum-containing formation penetrated by at least one injection well and by at least one production well, both wells being in fluid communication with the formation, said formation temperature being from about 70° F. to about 300° F., said petroleum formation also containing water whose salinity is from about 70,000 parts per million to about 220,000 parts per million total dissolved solids, comprising: (a) injecting an aqueous, saline surfactant fluid into the formation via the injection well, said fluid containing a surfactant having the following formula: RO(R'O).sub.n R"SO.sub.3.sup.- M.sup.+ in which R is an alkyl or alkylaryl radical having from 8 to 24 carbon atoms, R' is ethyl or a mixture of ethyl and propyl with relatively more ethyl than propyl, R" is ethyl, propyl, hydroxypropyl or butyl, n is a number from 1 to 20, and M + is a monovalent cation, wherein the number of carbon atoms in the alkyl chain and the number of ethylene oxide units are balanced to achieve the minimum interfacial tension at about the same salinity as the formation water and at a temperature about equal to the formation temperature, said surfactant fluid being injected at a temperature in degrees F which is at least equal to a value which is 100° less than the formation temperature in degrees F, said fluid displacing petroleum through the formation toward the production well; and (b) recovering petroleum from the formation via the production well.
Claim 2
Independent Claim
247 words
A method for recovering petroleum from a subterranean, permeable, petroleum-containing formation penetrated by at least one injection well and by at least one production well, both wells being in fluid communication with the formation, said formation temperature being from about 70° F. to about 300° F., said petroleum formation also containing water whose salinity is from about 70,000 parts per million to about 220,000 parts per million total dissolved solids, comprising: (a) injecting an aqueous, saline surfactant fluid into the formation via the injection well, said fluid containing a surfactant having the following formula: RO(R'O).sub.n R"SO.sub.3.sup.- M.sup.+ in which R is an alkyl or alkylaryl radical having from 8 to 24 carbon atoms, R' is ethyl or a mixture of ethyl and propyl with relatively more ethyl than propyl, R" is ethyl, propyl, hydroxypropyl or butyl, n is a number from 1 to 20, and M + is a monovalent cation, wherein the number of carbon atoms in the alkyl chain and the number of ethylene oxide units are balanced to achieve the minimum interfacial tension at about the same salinity as the formation water and at a temperature about equal to the formation temperature, said surfactant fluid being injected at a temperature in degrees F which is at least equal to a value which is 100° less than the formation temperature in degrees F, said fluid displacing petroleum through the formation toward the production well; and (b) recovering petroleum from the formation via the production well.
Claim 3
Dependent Claim
36 words
A method as recited in claim 1 wherein the surfactant fluid is injected at a temperature which is at least equal to a value which is 50° F less than the formation temperature in degrees F.
Claim 4
Dependent Claim
14 words
A method as recited in claim 1 wherein the surfactant is an alkylphenolpolyalkoxyalkyl sulfonate.
Claim 5
Dependent Claim
14 words
A method as recited in claim 1 wherein the surfactant is an alkylarylpolyethoxyalkyl sulfonate.
Claim 6
Dependent Claim
14 words
A method as recited in claim 4 wherein the surfactant is an alkylarylpolyethoxyethyl sulfonate.
Claim 7
Dependent Claim
14 words
A method as recited in claim 4 wherein the surfactant is an alkylarylpolyethoxyhydroxypropyl sulfonate.
Claim 8
Dependent Claim
14 words
A method as recited in claim 4 wherein the surfactant is an alkylarylpolyethoxypropyl sulfonate.
Claim 9
Dependent Claim
14 words
A method as recited in claim 4 wherein the surfactant is an alkylarylpolyethoxybutyl sulfonate.
Claim 10
Dependent Claim
14 words
A method as recited in claim 1 wherein the surfactant is an alkylpolyalkoxyalkyl sulfonate.
Claim 11
Dependent Claim
14 words
A method as recited in claim 9 wherein the surfactant is an alkylpolyethoxyalkyl sulfonate.
Claim 12
Dependent Claim
14 words
A method as recited in claim 10 wherein the surfactant is an alkylypolythoxyethyl sulfonate.
Claim 13
Dependent Claim
14 words
A method as recited in claim 9 wherein the surfactant is an alkylpolyethoxypropyl sulfonate.
Claim 14
Dependent Claim
14 words
A method as recited in claim 9 wherein the surfactant is an alkylpolyethoxyhydroxypropyl sulfonate.
Claim 15
Dependent Claim
14 words
A method as recited in claim 9 wherein the surfactant is an alkylpolyethoxybutyl sulfonate.
Claim 16
Dependent Claim
30 words
A method as recited in claim 1 wherein the surfactant fluid also contains a water insoluble nonionic surfactant selected from the group consisting of polyethoxylated aliphatic alcohols and polyethoxylated alkylphenols.
Claim 17
Dependent Claim
16 words
A method as recited in claim 1 wherein the surfactant fluid also contains an organic sulfonate.
Claim 18
Dependent Claim
14 words
A method as recited in claim 16 wherein the organic sulfonate is petroleum sulfonate.
Claim 19
Independent Claim
228 words
A method for recovering petroleum from a subterranean, permeable, petroleum-containing formation penetrated by at least one injection well and by at least one production well, both wells being in fluid communication with the formation, said formation temperature being from about 70° F. to about 300° F., said petroleum formation also containing water whose salinity is from about 70,000 parts per million to about 220,000 parts per million total dissolved solids, comprising: (a) injecting an aqueous, saline surfactant fluid into the formation via the injection well, said fluid containing a first surfactant having the following formula: RO(R'O).sub.n R"SO.sub.3.sup.- M.sup.+ in which R is an alkyl or alkylaryl radical having from 8 to 24 carbon atoms, R' is ethyl or a mixture of ethyl and propyl with relatively more ethyl than propyl, R" is ethyl, propyl, hydroxpropyl or butyl, n is an number from 1 to 20, and M + is a monovalent cation, and a second surfactant which is a water insoluble nonionic surfactant selected from the group consisting of polyethoxylated aliphatic alcohols and polyethoxylated alkylphenols, said surfactant fluid being injected at a temperature in degrees F which is at least equal to a value which is 100° less than the formation temperature in degrees F, said surfactant fluid displacing petroleum through the formation toward the production well; and (b) recovering petroleum from the formation via the production well.
Claim 20
Independent Claim
228 words
A method for recovering petroleum from a subterranean, permeable, petroleum-containing formation penetrated by at least one injection well and by at least one production well, both wells being in fluid communication with the formation, said formation temperature being from about 70° F. to about 300° F., said petroleum formation also containing water whose salinity is from about 70,000 parts per million to about 220,000 parts per million total dissolved solids, comprising: (a) injecting an aqueous, saline surfactant fluid into the formation via the injection well, said fluid containing a first surfactant having the following formula: RO(R'O).sub.n R"SO.sub.3.sup.- M.sup.+ in which R is an alkyl or alkylaryl radical having from 8 to 24 carbon atoms, R' is ethyl or a mixture of ethyl and propyl with relatively more ethyl than propyl, R" is ethyl, propyl, hydroxpropyl or butyl, n is an number from 1 to 20, and M + is a monovalent cation, and a second surfactant which is a water insoluble nonionic surfactant selected from the group consisting of polyethoxylated aliphatic alcohols and polyethoxylated alkylphenols, said surfactant fluid being injected at a temperature in degrees F which is at least equal to a value which is 100° less than the formation temperature in degrees F, said surfactant fluid displacing petroleum through the formation toward the production well; and (b) recovering petroleum from the formation via the production well.
Claim 21
Dependent Claim
36 words
A method as recited in claim 18 wherein the surfactant fluid is injected at a temperature which is at least equal to a value which is 50° F less than the formation temperature in degrees F.
Claim 22
Dependent Claim
15 words
A method as recited in claim 18 wherein the first surfactant is an alkylarylpolyethoxyalkyl sulfonate.
Claim 23
Dependent Claim
15 words
A method as recited in claim 18 wherein the first surfactant is an alkylarylpolyethoxyethyl sulfonate.
Claim 24
Dependent Claim
15 words
A method as recited in claim 18 wherein the first surfactant is an alkylarylpolyethoxyhydroxypropyl sulfonate.
Claim 25
Dependent Claim
15 words
A method as recited in claim 18 wherein the first surfactant is an alkylarylpolyethoxypropyl sulfonate.
Claim 26
Dependent Claim
15 words
A method as recited in claim 18 wherein the first surfactant is an alkylarylpolyethoxybutyl sulfonate.
Claim 27
Dependent Claim
15 words
A method as recited in claim 18 wherein the first surfactant is an alkylpolyalkoxyalkyl sulfonate.
Claim 28
Dependent Claim
14 words
A method as recited in claim 25 wherein the surfactant is an alkylpolyethoxyethyl sulfonate.
Claim 29
Dependent Claim
14 words
A method as recited in claim 25 wherein the surfactant is an alkylpolyethoxypropyl sulfonate.
Claim 30
Dependent Claim
14 words
A method as recited in claim 25 wherein the surfactant is an alkylpolyethoxyhydroxypropyl sulfonate.
Claim 31
Dependent Claim
14 words
A method as recited in claim 25 wherein the surfactant is an alkylpolyethoxybutyl sulfonate.
Claim 32
Dependent Claim
16 words
A method as recited in claim 18 wherein the surfactant fluid also contains an organic sulfonate.
Claim 33
Dependent Claim
14 words
A method as recited in claim 30 wherein the organic sulfonate is petroleum sulfonate.
Claim 34
Dependent Claim
31 words
A method as recited in claim 31 wherein the surfactant fluid also contains a water insoluble nonionic surfactant selected from the group consisting of polyethoxylated aliphatic alcohols and polyethoxylated alkyl phenols
Claim 35
Independent Claim
262 words
A method for recovering petroleum from a subterranean, permeable, petroleum-containing formation penetrated by at least one injection well and by at least one production well, both wells being in fluid communication with the formation, said formation temperature being at least 100° F greater than surface ambient temperature, said petroleum formation also containing water whose salinity is from about 70,000 parts per million to about 220,000 parts per million total dissolved solids, comprising: (a) injecting an aqueous, saline surfactant fluid into the formation via the injection well, said fluid containing a surfactant having the following formula: RO(R'O).sub.n R"SO.sub.3.sup.- M.sup.+ in which R is an alkyl or alkylaryl radical having from 8 to 24 carbon atoms, R' is ethyl or a mixture of ethyl and propyl with relatively more ethyl than propyl, R" is ethyl, propyl, hydroxypropyl or butyl, n is a number from 1 to 20, and M + is a monovalent cation, the number of carbon atoms in the alkyl chain and the value of n being balanced so the fluid achieves the minimum interfacial tension at a temperature about equal to the formation temperature in an aqueous fluid whose salinity is about equal to the salinity of the formation water, which surfactant is insoluble at surface ambient temperature, said surfactant fluid being injected at a temperature in degrees F which is at least equal to a value which is 50° less than the formation temperature in degrees F, said surfactant fluid displacing petroleum through the formation toward the production well; and (b) recovering petroleum from the formation via the production well.
Claim 36
Independent Claim
262 words
A method for recovering petroleum from a subterranean, permeable, petroleum-containing formation penetrated by at least one injection well and by at least one production well, both wells being in fluid communication with the formation, said formation temperature being at least 100° F greater than surface ambient temperature, said petroleum formation also containing water whose salinity is from about 70,000 parts per million to about 220,000 parts per million total dissolved solids, comprising: (a) injecting an aqueous, saline surfactant fluid into the formation via the injection well, said fluid containing a surfactant having the following formula: RO(R'O).sub.n R"SO.sub.3.sup.- M.sup.+ in which R is an alkyl or alkylaryl radical having from 8 to 24 carbon atoms, R' is ethyl or a mixture of ethyl and propyl with relatively more ethyl than propyl, R" is ethyl, propyl, hydroxypropyl or butyl, n is a number from 1 to 20, and M + is a monovalent cation, the number of carbon atoms in the alkyl chain and the value of n being balanced so the fluid achieves the minimum interfacial tension at a temperature about equal to the formation temperature in an aqueous fluid whose salinity is about equal to the salinity of the formation water, which surfactant is insoluble at surface ambient temperature, said surfactant fluid being injected at a temperature in degrees F which is at least equal to a value which is 50° less than the formation temperature in degrees F, said surfactant fluid displacing petroleum through the formation toward the production well; and (b) recovering petroleum from the formation via the production well.
Claim 37
Dependent Claim
16 words
A method as recited in claim 33 wherein the surfactant fluid also contains an organic sulfonate.
Claim 38
Dependent Claim
14 words
A method as recited in claim 34 wherein the organic sulfonate is petroleum sulfonate.