# US 11,898,093 B2 · Injection well cleaning fluids and related methods

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- Number: US 11,898,093 B2
- Document ID: US11898093B2
- Status: Granted
- Kind: B2
- Application number: 18/202,833
- Filed: 2023-05-26
- Published: 2023-11-09
- Granted: 2024-02-13
- Earliest claimed: 2021-02-04
- Assignees: Baker Hughes Oilfield Operations LLC
- Applicants: Baker Hughes Oilfield Operations LLC
- Inventors: Lirio Quintero; Jeffrey A. Russek
- Web page: https://patentgrep.com/patent/US11898093B2

## CPC

- C09K 8/528: inorganic depositions, e.g. sulfates or carbonates
- E21B 37/06: using chemical means for preventing or limiting {, e.g. eliminating,} the deposition of paraffins or like substances
- C09K 8/74: combined with additives added for specific purposes
- C09K: MATERIALS FOR MISCELLANEOUS APPLICATIONS, NOT PROVIDED FOR ELSEWHERE
- E21B: EARTH OR ROCK DRILLING; OBTAINING OIL, GAS, WATER, SOLUBLE OR MELTABLE MATERIALS OR A SLURRY OF MINERALS FROM WELLS

## Abstract

Methods can include introducing a cleaning fluid into a near-wellbore zone of an injection well penetrating a subterranean formation, wherein the cleaning fluid includes: 0.5 wt % to about 5 wt % of a surfactant blend comprising an alkoxy carbonate surfactant and an internal olefin sulfonate surfactant; salt water having a total dissolved solids (TDS) of about 15,000 mg/L or greater; and 0 wt % to about 0.05 wt % of an organic acid; and dispersing a hydrocarbon from the near-wellbore zone in the cleaning fluid. Compositions for cleaning a near-wellbore zone of a subterranean formation can include 0.5 wt % to about 5 wt % of a surfactant blend comprising an alkoxy carbonate surfactant and an internal olefin sulfonate surfactant; salt water having a total dissolved solids (TDS) of about 15,000 mg/L or greater; and 0 wt % to about 0.05 wt % of an organic acid.

## Claims

### Claim 1

A composition comprising:
0.5 wt % to about 5 wt % of a surfactant blend comprising an alkoxy carbonate surfactant and an internal olefin sulfonate surfactant;
salt water having a total dissolved solids (TDS) of about 15,000 mg/L or greater;
0 wt % to about 0.05 wt % of an organic acid; and
an acidizing fluid comprising water and an acid selected from the group consisting of hydrofluoric acid, hydrochloric acid, acetic acid, formic acid, phosphoric acid, and combinations thereof, where the acid is present in a sufficient amount to cause the acidizing fluid to have a pH of about 1.5 to about 5.5;
wherein the composition has an interfacial tension at 60° C. with crude oil having a viscosity 2.5 cP at 60° C. and viscosity of 0.5 cP at 90° C. of about 0.1 mN/m or less.

### Claim 2 (depends on 1)

The composition of claim 1, wherein the alkoxy carbonate surfactant comprises a surfactant according to Formula I
where R1 is a C8-C24 alkyl, a C8-C24 cyclo-alkyl, or a C8-C24 aryl-alkyl
where n is an integer from 1 to 30.

### Claim 3 (depends on 1)

The composition of claim 1, wherein the alkoxy carbonate surfactant comprises a surfactant according to Formula II
where R2 is a C8-C24 alkyl, a C8-C24 cyclo-alkyl, or a C8-C24 aryl-alkyl
where m is an integer from 1 to 30.

### Claim 4 (depends on 1)

The composition of claim 1, wherein the internal olefin sulfonate surfactant comprises a surfactant according to Formula III
where R3 is a C1-C20 alkyl, a C1-C20 cyclo-alkyl, or a C1-C20 aryl-alkyl
where R4 is a C1-C20 alkyl, a C1-C20 cyclo-alkyl, or a C1-C20 aryl-alkyl
where X+ is a cation of hydrogen, lithium, sodium, or potassium.

### Claim 5 (depends on 1)

The composition of claim 1, wherein the internal olefin sulfonate surfactant comprises a surfactant according to Formula I
where R5 is a C1-C20 alkyl, a C1-C20 cyclo-alkyl, or a C1-C20 aryl-alkyl
where R6 is a C1-C20 alkyl, a C1-C20 cyclo-alkyl, or a C1-C20 aryl-alkyl
where R7 is a C1-C20 alkyl, a C1-C20 cyclo-alkyl, or a C1-C20 aryl-alkyl where X+ is a cation of hydrogen, lithium, sodium, or potassium.

### Claim 6 (depends on 1)

The composition of claim 1, wherein a weight ratio of the alkoxy carbonate surfactant to the internal olefin sulfonate surfactant is about 80:20 to about 20:80.

### Claim 7 (depends on 1)

The composition of claim 1, wherein the salt water has a TDS of about 15,000 mg/L to about 50,000 mg/L.

### Claim 8 (depends on 1)

The composition of claim 1, wherein the organic acid is present at about 0.001 wt % to about 0.05 wt % of the cleaning fluid.

### Claim 9 (depends on 8)

The composition of claim 8, wherein the organic acid is present and comprises one or more selected from the group consisting of: acetic acid, formic acid, glycolic acid, lactic acid, succinic acid, malic acid, oxalic acid, citric acid, benzoic acid, salicylic acid, butyric acid, ascorbic acid, and any combination thereof.

### Claim 10

A composition comprising:
0.5 wt % to about 5 wt % of a surfactant blend comprising an alkoxy carbonate surfactant and an internal olefin sulfonate surfactant;
salt water having a total dissolved solids (TDS) of about 15,000 mg/L to about 50,000 mg/L;
an organic acid present at about 0.001 wt % to about 0.05 wt % of the cleaning fluid; and
an acidizing fluid comprising water and an acid selected from the group consisting of hydrofluoric acid, hydrochloric acid, acetic acid, formic acid, phosphoric acid, and combinations thereof, where the acid is present in a sufficient amount to cause the acidizing fluid to have a pH of about 1.5 to about 5.5;
wherein the composition has an interfacial tension at 60° C. with crude oil having a viscosity 2.5 cP at 60° C. and viscosity of 0.5 cP at 90° C. of about 0.1 mN/m or less.

### Claim 11 (depends on 10)

The composition of claim 10, wherein the alkoxy carbonate surfactant comprises a surfactant according to Formula I
where R1 is a C8-C24 alkyl, a C8-C24 cyclo-alkyl, or a C8-C24 aryl-alkyl
where n is an integer from 1 to 30.

### Claim 12 (depends on 10)

The composition of claim 10, wherein the alkoxy carbonate surfactant comprises a surfactant according to Formula II
where R2 is a C8-C24 alkyl, a C8-C24 cyclo-alkyl, or a C8-C24 aryl-alkyl
where m is an integer from 1 to 30.

### Claim 13 (depends on 10)

The composition of claim 10, wherein the internal olefin sulfonate surfactant comprises a surfactant according to Formula III
where R3 is a C1-C20 alkyl, a C1-C20 cyclo-alkyl, or a C1-C20 aryl-alkyl
where R4 is a C1-C20 alkyl, a C1-C20 cyclo-alkyl, or a C1-C20 aryl-alkyl
where X+ is a cation of hydrogen, lithium, sodium, or potassium.

### Claim 14 (depends on 10)

The composition of claim 10, wherein the internal olefin sulfonate surfactant comprises a surfactant according to Formula I
where R5 is a C1-C20 alkyl, a C1-C20 cyclo-alkyl, or a C1-C20 aryl-alkyl
where R6 is a C1-C20 alkyl, a C1-C20 cyclo-alkyl, or a C1-C20 aryl-alkyl
where R7 is a C1-C20 alkyl, a C1-C20 cyclo-alkyl, or a C1-C20 aryl-alkyl
where X+ is a cation of hydrogen, lithium, sodium, or potassium.

### Claim 15 (depends on 10)

The composition of claim 10, wherein a weight ratio of the alkoxy carbonate surfactant to the internal olefin sulfonate surfactant is about 80:20 to about 20:80.

### Claim 16 (depends on 10)

The composition of claim 10, wherein the organic acid is present and comprises one or more selected from the group consisting of: acetic acid, formic acid, glycolic acid, lactic acid, succinic acid, malic acid, oxalic acid, citric acid, benzoic acid, salicylic acid, butyric acid, ascorbic acid, and any combination thereof.

### Claim 17

A composition comprising:
0.5 wt % to about 5 wt % of a surfactant blend comprising an alkoxy carbonate surfactant and an internal olefin sulfonate surfactant;
salt water having a total dissolved solids (TDS) of about 15,000 mg/L or greater;
about 0.001 wt % to about 0.05 wt % of an organic acid selected from the group consisting of acetic acid, formic acid, glycolic acid, lactic acid, succinic acid, malic acid, oxalic acid, citric acid, benzoic acid, salicylic acid, butyric acid, ascorbic acid, and any combination thereof; and
an acidizing fluid comprising water and an acid selected from the group consisting of hydrofluoric acid, hydrochloric acid, acetic acid, formic acid, phosphoric acid, and combinations thereof, where the acid is present in a sufficient amount to cause the acidizing fluid to have a pH of about 1.5 to about 5.5;
wherein the composition has an interfacial tension at 60° C. with crude oil having a viscosity 2.5 cP at 60° C. and viscosity of 0.5 cP at 90° C. of about 0.1 mN/m or less.

### Claim 18 (depends on 17)

The composition of claim 17, wherein a weight ratio of the alkoxy carbonate surfactant to the internal olefin sulfonate surfactant is about 80:20 to about 20:80.

### Claim 19 (depends on 17)

The composition of claim 17, wherein the salt water has a TDS of about 15,000 mg/L to about 50,000 mg/L.