Phosphate ester/alcohol micellar solutions in well acidizing

Claim 2

An aqueous acid containing oil and gas well treating solution comprising: (a) an aqueous acid continuous phase; (b) a C 4 to C 10 substantially water insoluble aliphatic alcohol; and (c) an effective amount of a phosphate ester surfactant to render said alcohol soluble in said aqueous acid continuous phase wherein said phosphate ester surfactant is characterized by the formulas: ##STR3## where R is about a C 8 to C 18 alkyl group or about a C 8 to C 9 alkyl substituted phenyl group, x is from about 2 to 6 and y is from about 12 to 22 and wherein the 2 to 6 units of propylene oxide are substantially a block polymer attached to the R--O group and wherein the 12 to 22 units of ethylene oxide are substantially a block polymer, wherein at least 75 parts by volume of said aqueous acid continuous phase containing up to 28 wt.% acid is combined with up to 25 parts by volume of a mixture of said alcohol and said phosphate ester surfactant wherein said mixture comprises up to about 8 parts by volume surfactant.

Claim 3

A treating solution of claim 1 wherein said acid is selected from the group consisting of HCl, HF, acetic, sulfamic, citric, glycolic, NH 4 HF 2 , and mixtures thereof.

Claim 4

A treating solution of claim 1 wherein said aliphatic alcohol is a C 6 to C 8 alcohol.

Claim 5

A treating solution of claim 1 wherein said phosphate ester surfactant is a phosphate ester of an oxyalkylated fatty alcohol.

Claim 6

A treating solution of claim 1 wherein said acid is HCl, HF or mixtures thereof, said aliphatic alcohol is octyl or capryl alcohol, and said phosphate ester surfactant is a phosphate ester of oxyalkylated fatty alcohol.

Claim 7

A treating solution of claim 5 wherein said aqueous acid continuous phase is 15 wt. % HCl, said aliphatic alcohol is isooctyl alcohol, and said phosphate ester surfactant is oxirane, methyl-, polymer with oxirane, mono-C 10 -C 18 -alkyl ethers, phosphates.

Claim 8

A treating solution of claim 1 further comprising an effective amount of a low molecular weight water soluble alcohol or diol.

Claim 9

A treating solution of claim 1 wherein at least 90 parts by volume of said acid is combined with up to 10 parts by volume of said mixture.

Claim 10

An acidizing additive comprising: (a) a C 4 to C 10 substantially water insoluble aliphatic alcohol; (b) a phosphate ester surfactant characterized by the formulas: ##STR4## where R is about a C 8 to C 18 alkyl group or about a C 8 to C 9 alkyl substituted phenyl group, x is from about 2 to 6 and y is from about 12 to 22 and wherein the 2 to 6 units of propylene oxide are substantially a block polymer attached to the R--O group and wherein the 12 to 22 units of ethylene oxide are substantially a block polymer; (c) a water soluble low molecular weight alcohol or diol; and (d) water, wherein said insoluble aliphatic alcohol is present in an amount of 20 to 160 parts by volume of said surfactant and the volume of the water soluble alochol or diol plus water is approximately equal to the sum of the volumes of the surfactant and the insoluble alcohol and wherein the water is present in a range of about 2 to 20 volume percent of the resulting additive.

Claim 11

An acidizing additive comprising: (a) a C 4 to C 10 substantially water insoluble aliphatic alcohol; (b) a phosphate ester surfactant characterized by the formulas: ##STR4## where R is about a C 8 to C 18 alkyl group or about a C 8 to C 9 alkyl substituted phenyl group, x is from about 2 to 6 and y is from about 12 to 22 and wherein the 2 to 6 units of propylene oxide are substantially a block polymer attached to the R--O group and wherein the 12 to 22 units of ethylene oxide are substantially a block polymer; (c) a water soluble low molecular weight alcohol or diol; and (d) water, wherein said insoluble aliphatic alcohol is present in an amount of 20 to 160 parts by volume of said surfactant and the volume of the water soluble alochol or diol plus water is approximately equal to the sum of the volumes of the surfactant and the insoluble alcohol and wherein the water is present in a range of about 2 to 20 volume percent of the resulting additive.

Claim 12

An acidizing additive of claim 9 wherein said water soluble low molecular weight alcohol or diol is selected from the group consisting of methanol, ethanol, n-propanol, isopropyl alcohol, t-butyl alcohol, and ethylene glycol.

Claim 13

An acidizing additive of claim 9 wherein said water insoluble alcohol is a C 6 to C 8 alcohol and said surfactant is a phosphate ester of an oxyalkylated fatty alcohol.

Claim 14

An acidizing additive of claim 10 wherein said water insoluble alcohol is a C 6 to C 8 alcohol and said surfactant is a phosphate ester of an oxyalkylated fatty alcohol.

Claim 15

An acidizing additive of claim 9 wherein the ratio of substantially water insoluble aliphatic alcohol to surfactant ranges from about 1 part by volume alcohol per 4 parts by volume surfactant to 8 parts by volume alcohol per 5 parts by volume surfactant.

Claim 16

An acidizing additive of claim 13 wherein the ratio of substantially water insoluble aliphatic alcohol to surfactant is about two to three.

Claim 17

An acidizing additive of claim 9 wherein said water is present in at least 2% by volume and less than about 20% by volume.

Claim 18

An acidizing additive of claim 15 wherein the ratio of substantially water insoluble aliphatic alcohol to surfactant ranges from about 1 part by volume alcohol per 4 parts by volume surfactant to 8 parts by volume alcohol per 5 parts per volume surfactant.

Claim 19

An acidizing additive of claim 16 wherein said ratio of substantially water insoluble aliphatic alcohol to surfactant is about two to three.

Claim 20

An acidizing additive of claim 16 wherein said water insoluble alcohol is a C 6 to C 8 alcohol.

Claim 21

An acidizing additive of claim 16 wherein said insoluble alcohol is isooctyl alcohol.

Claim 22

A process for treating an oil-bearing formation comprising the step of contacting said formation with an aqueous acid solution containing up to 28 wt.% acid and containing up to 25 parts by volume of a combination of a C 4 to C 10 substantially water insoluble aliphatic alcohol and an effective amount of a phosphate ester surfactant to render said alcohol soluble in said acid solution wherein said phosphate ester surfactant is characterized by the formulas: ##STR5## where R is about a C 8 to C 18 alkyl group or about a C 8 to C 9 alkyl substituted phenyl group, x is from about 2 to 6 and y is from about 12 to 22 and wherein the 2 to 6 units of propylene oxide are subtantially a block polymer attached to the R--O group and wherein the 12 to 22 units of ethylene oxide are substantially a block polymer and wherein said combination comprises up to about 8 parts by volume of said water insoluble alcohol to 5 parts by volume surfactant.

Claim 23

A process for treating an oil-bearing formation comprising the step of contacting said formation with an aqueous acid solution containing up to 28 wt.% acid and containing up to 25 parts by volume of a combination of a C 4 to C 10 substantially water insoluble aliphatic alcohol and an effective amount of a phosphate ester surfactant to render said alcohol soluble in said acid solution wherein said phosphate ester surfactant is characterized by the formulas: ##STR5## where R is about a C 8 to C 18 alkyl group or about a C 8 to C 9 alkyl substituted phenyl group, x is from about 2 to 6 and y is from about 12 to 22 and wherein the 2 to 6 units of propylene oxide are subtantially a block polymer attached to the R--O group and wherein the 12 to 22 units of ethylene oxide are substantially a block polymer and wherein said combination comprises up to about 8 parts by volume of said water insoluble alcohol to 5 parts by volume surfactant.

Claim 24

A process of claim 20 wherein said phosphate ester surfactant is a phosphate ester of an oxyalkylated fatty alcohol.

Claim 25

A process of claim 20 wherein said aliphatic alcohol is a C 6 to C 8 alcohol.

Claim 26

A process of claim 21 wherein said aliphatic alcohol is a C 6 to C 8 alcohol.

Claim 27

A process of claim 20 wherein said aliphatic alcohol is isooctyl alcohol.

Claim 28

A process of claim 21 wherein said aliphatic alcohol is isooctyl alcohol.

Claim 29

A process of claim 21 wherein said phosphate ester surfactant is oxirane, methyl-, polymer with oxirane, mono-C 10 -C 18 -alkyl ethers, phosphates.

Claim 30

A process of claim 20 wherein said aqueous acid solution also contains a water soluble low molecular weight alcohol or diol.

Claim 31

An aqueous acid containing oil and gas well treating solution comprising: (a) an aqueous acid continuous phase; (b) a substantially water insoluble alcohol of the formula: R.sub.1 -R.sub.2 O--CH.sub.2 CH.sub.2 -O].sub.x CH.sub.2 CH.sub.2 OH where R 1 is a CH 3 -- or --CH 2 CH 2 OH; R 2 is a C 11 to C 21 hydrocarbon chain, polypropylene oxide, polybutylene oxide or --(CH 2 --) 10 to 20 CO-fatty acid residue, and x is an integer from about 3 to 15; and (c) an effective amount of a phosphate ester surfactant to render said alcohol soluble in said aqueous acid continuous phase wherein said phosphate ester surfactant is characterized by the formulas: ##STR6## where R is about a C 8 to C 18 alkyl group or about a C 8 to C 9 alkyl substituted phenyl group, x is from about 2 to 6 and y is from about 12 to 22 and wherein the 2 to 6 units of propylene oxide are substantially a block polymer attached to the R--O group and wherein the 12 to 22 units of ethylene oxide are substantially a block polymer wherein at least 75 parts by volume of said aqueous acid continuous phase containing up to 28 wt.% acid is combined with up to 25 parts by volume of a mixture of said alcohol and said phosphate ester surfactant wherein said mixture comprises up to about 8 parts by volume surfactant.

Claim 32

An aqueous acid containing oil and gas well treating solution comprising: (a) an aqueous acid continuous phase; (b) a substantially water insoluble alcohol of the formula: R.sub.1 -R.sub.2 O--CH.sub.2 CH.sub.2 -O].sub.x CH.sub.2 CH.sub.2 OH where R 1 is a CH 3 -- or --CH 2 CH 2 OH; R 2 is a C 11 to C 21 hydrocarbon chain, polypropylene oxide, polybutylene oxide or --(CH 2 --) 10 to 20 CO-fatty acid residue, and x is an integer from about 3 to 15; and (c) an effective amount of a phosphate ester surfactant to render said alcohol soluble in said aqueous acid continuous phase wherein said phosphate ester surfactant is characterized by the formulas: ##STR6## where R is about a C 8 to C 18 alkyl group or about a C 8 to C 9 alkyl substituted phenyl group, x is from about 2 to 6 and y is from about 12 to 22 and wherein the 2 to 6 units of propylene oxide are substantially a block polymer attached to the R--O group and wherein the 12 to 22 units of ethylene oxide are substantially a block polymer wherein at least 75 parts by volume of said aqueous acid continuous phase containing up to 28 wt.% acid is combined with up to 25 parts by volume of a mixture of said alcohol and said phosphate ester surfactant wherein said mixture comprises up to about 8 parts by volume surfactant.

Claim 33

A process for treating an oil bearing formation comprising the step of contacting said formation with a composition of claim 28.