US4293428A — Propoxylated ethoxylated surfactants and method o…

Claim 1

Independent Claim 126 words

A method for recovering oil from an oil-bearing formation which comprises injecting into said formation a fluid containing an effective amount of surface-active agent having the general formula: R.sub.1 O(C.sub.3 H.sub.6 O).sub.m (C.sub.2 H.sub.4 O).sub.n YX wherein R 1 is a linear or branched alkyl radical, an alkenyl radical, or an alkyl or alkenyl substituted benzene radical, the non-aromatic portion of the radical containing from 6 to 24 carbon atoms; m has an average value of from about 1 to about 10; n has an average value of from about 1 to about 10; Y is a sulfate, sulfonate, phosphate, or carboxylate group; and X is a cation; and driving said fluid through said formation to displace oil from said formation and recovering the displaced oil.

Claim 2

Independent Claim 126 words

A method for recovering oil from an oil-bearing formation which comprises injecting into said formation a fluid containing an effective amount of surface-active agent having the general formula: R.sub.1 O(C.sub.3 H.sub.6 O).sub.m (C.sub.2 H.sub.4 O).sub.n YX wherein R 1 is a linear or branched alkyl radical, an alkenyl radical, or an alkyl or alkenyl substituted benzene radical, the non-aromatic portion of the radical containing from 6 to 24 carbon atoms; m has an average value of from about 1 to about 10; n has an average value of from about 1 to about 10; Y is a sulfate, sulfonate, phosphate, or carboxylate group; and X is a cation; and driving said fluid through said formation to displace oil from said formation and recovering the displaced oil.

Claim 3

Dependent Claim 52 words

The method of claim 1 wherein Y is a sulfonate having the general formula ##STR3## wherein R 2 is an alkyl, cycloalkyl, alkenyl, alkylaryl, or aryl radical containing up to 8 carbon atoms; and R 3 is a hydrogen atom, a hydroxyl radical, or an aliphatic radical containing from 1-8 carbon atoms.

Claim 4

Dependent Claim 20 words

The method of claim 1 wherein R 1 is a branched alkyl substituent containing from 10 to 16 carbon atoms.

Claim 5

Dependent Claim 29 words

The method of claim 1 wherein m has an average value of about 2 to about 6 and n has an average value of about 2 to about 6.

Claim 6

Dependent Claim 15 words

The method of claim 1 wherein said fluid is an aqueous fluid containing inorganic salts.

Claim 7

Dependent Claim 14 words

The method of claim 5 wherein said aqueous fluid is brine from said formation.

Claim 8

Dependent Claim 43 words

The method of claim 5 wherein the values of m and n are varied with respect to each other in proportion to the concentration of said inorganic salts in said aqueous fluid so as to optimize the surface activity of said surface-active agent.

Claim 9

Dependent Claim 11 words

The method of claim 1 wherein said fluid is a microemulsion.

Claim 10

Dependent Claim 19 words

The method of claim 8 wherein said microemulsion is driven through said formation by a slug of thickened water.

Claim 11

Dependent Claim 12 words

The method of claim 8 wherein said microemulsion further includes a co-surfactant.

Claim 12

Dependent Claim 12 words

The method of claim 8 wherein said microemulsion further includes a co-solvent.

Claim 13

Dependent Claim 11 words

The method of claim 8 wherein said microemulsion includes a thickener.

Claim 14

Dependent Claim 11 words

The method of claim 8 wherein said microemulsion contains inorganic salts.

Claim 15

Dependent Claim 49 words

The method of claim 13 wherein the values of m and n are varied according to a set of curves defined at varying concentrations of said inorganic salts, said curves being generated by measuring optimum salinities as a function of m and n at each of said varying concentrations.

Claim 16

Dependent Claim 151 words

The method of claim 8 wherein the precise values of m and n are selected from a plot obtained by: (a) preparing a plurality of surface-active agents characterized by said general formula and having different average values of m and n; (b) preparing a microemulsion sample which includes one of said plurality of surface-active agents, water, oil, and inorganic salts, the concentration of said salts being such that a balanced minimum microemulsion-oil and microemulsion-water interfacial tension is obtained; (c) repeating step (b) for each of said plurality of surface-active agents; (d) plotting those values of m versus n which give minimum microemulsion-oil and microemulsion-water interfacial tensions at one concentration of said salts, thereby generating a curve; (e) repeating step (d) for other concentrations of said salts to generate a family of curves, each curve defining values of m and n giving balanced minimum interfacial tensions at different concentrations of said salts.

Claim 17

Dependent Claim 49 words

The method of claim 1 wherein said surface-active agent is an i-tridecyl ether (C 3 H 6 O) m (C 2 H 4 O) n sulfate, the value of m ranging from about 2 to about 6 and the value of n ranging from about 2 to about 6.

Claim 18

Dependent Claim 14 words

The method of claim 16 wherein said formation contains high concentrations of inorganic salts.

Claim 19

Independent Claim 96 words

The method of enhanced oil recovery which comprises injecting a microemulsion containing an effective amount of surfactant having the general formula: R.sub.1 O(C.sub.3 H.sub.6 O).sub.m (C.sub.2 H.sub.4 O).sub.n YX wherein R 1 is a C 10-16 branched chain alkyl radical having at least two branching groups; m has an average value of between about 2 and about 6; n has an average value of between about 2 and about 6; Y is the sulfate or sulfonate group; and X is a cation; and driving said microemulsion through said formation to displace oil to a producing well.

Claim 20

Independent Claim 96 words

The method of enhanced oil recovery which comprises injecting a microemulsion containing an effective amount of surfactant having the general formula: R.sub.1 O(C.sub.3 H.sub.6 O).sub.m (C.sub.2 H.sub.4 O).sub.n YX wherein R 1 is a C 10-16 branched chain alkyl radical having at least two branching groups; m has an average value of between about 2 and about 6; n has an average value of between about 2 and about 6; Y is the sulfate or sulfonate group; and X is a cation; and driving said microemulsion through said formation to displace oil to a producing well.

Claim 21

Dependent Claim 12 words

The method of claim 18 wherein R 1 is an i-tridecyl radical.

Claim 22

Dependent Claim 29 words

The method of claim 18 wherein said surfactant is present in an amount ranging from about 1 to about 20 volume percent based on the volume of said microemulsion.

Claim 23

Dependent Claim 17 words

The method of claim 20 wherein the range is from about 2 to about 12 volume percent.

Claim 24

Dependent Claim 137 words

A formulation suitable for injection into a hydrocarbon-bearing formation for enhanced recovery operations which comprises: (a) 0.25-90% by volume of oil; (b) 1-95% by volume water; (c) 1-20% by volume of a surfactant having the general formula: R.sub.1 O(C.sub.3 H.sub.6 O).sub.m (C.sub.2 H.sub.4 O).sub.n YX wherein R 1 is a linear or branched alkyl radical, an alkenyl radical, or an alkyl or alkenyl substituted benzene radical, the non-aromatic portion of the radical containing from 6 to 24 carbon atoms; m has an average value of from about 1 to about 10; n has an average value of from about 1 to about 10; Y is a sulfate, sulfonate, phosphate or carboxylate group; and X is a cation; (d) 0-250 g/l inorganic salts; (e) 0-15% by volume of a co-surfactant; and (f) 0-2% by volume of a thickener.

Claim 25

Dependent Claim 137 words

A formulation suitable for injection into a hydrocarbon-bearing formation for enhanced recovery operations which comprises: (a) 0.25-90% by volume of oil; (b) 1-95% by volume water; (c) 1-20% by volume of a surfactant having the general formula: R.sub.1 O(C.sub.3 H.sub.6 O).sub.m (C.sub.2 H.sub.4 O).sub.n YX wherein R 1 is a linear or branched alkyl radical, an alkenyl radical, or an alkyl or alkenyl substituted benzene radical, the non-aromatic portion of the radical containing from 6 to 24 carbon atoms; m has an average value of from about 1 to about 10; n has an average value of from about 1 to about 10; Y is a sulfate, sulfonate, phosphate or carboxylate group; and X is a cation; (d) 0-250 g/l inorganic salts; (e) 0-15% by volume of a co-surfactant; and (f) 0-2% by volume of a thickener.

Claim 26

Dependent Claim 52 words

The formulation of claim 22 wherein Y is a sulfonate having the general formula ##STR4## wherein R 2 is an alkyl, cycloalkyl, alkenyl, alkylaryl or aryl radical containing up to 8 carbon atoms; and R 3 is a hydrogen atom, a hydroxyl radical, or an aliphatic radical containing from 1-8 carbon atoms.

Claim 27

Dependent Claim 22 words

The formulation of claim 22 wherein R 1 is a C 10-16 branched chain alkyl radical having at least two branching groups.

Claim 28

Dependent Claim 31 words

The formulation of claim 24 wherein m has an average value of from about 2 to about 6 and n has an average value of from about 2 to about 6.

Claim 29

Dependent Claim 49 words

The formulation of claim 22 wherein said formation contains a brine having a known composition of inorganic salts and wherein the amount of components (a)-(d) are respectively: (a) 0.25-1% (b) 80-95% (c) 2%-12% (d) substantially the same as that of said brine and components (e) and (f) are omitted.

Annuity Stage	Window Opens	Payment Deadline	Surcharge Period Until	Estimated Fee	Status
3.5 Years (Year 4)	1984-10-05	1985-04-06	1985-10-06	$2000.00	Window Closed / Lapsed
7.5 Years (Year 8)	1988-10-05	1989-04-06	1989-10-06	$3760.00	Window Closed / Lapsed
11.5 Years (Year 12)	1992-10-05	1993-04-06	1993-10-06	$7700.00	Window Closed / Lapsed

Propoxylated ethoxylated surfactants and method of recovering oil therewith

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