# US 2023/0235218 A1 · Manipulating hydrophilicity of conventional dye molecules for tracer applications

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- Number: US 2023/0235218 A1
- Document ID: US20230235218A1
- Status: Published application
- Kind: A1
- Application number: 18/193,299
- Filed: 2023-03-30
- Published: 2023-07-27
- Earliest claimed: 2021-12-13
- Assignees: Saudi Arabian Oil Company
- Applicants: Saudi Arabian Oil Company
- Inventors: Wei Wang
- Web page: https://patentgrep.com/patent/US20230235218A1

## CPC

- C09K 11/06: containing organic luminescent materials
- C09B 11/22: containing OH groups bound to an aryl nucleus {and their ethers and esters}
- C09B 11/24: Phthaleins containing amino groups {; Phthalanes; Fluoranes; Phthalides; Rhodamine dyes; Phthaleins having heterocyclic aryl rings; Lactone or lactame forms of triarylmethane dyes}
- C09B 68/4235: {Ammonium groups or derivatives thereof}
- C09B 68/4253: {Sulfonic acid groups}
- C09B 68/463: {Substituted aromatic groups}
- C09K 8/035: Organic additives
- C09K 8/62: Compositions for forming crevices or fractures
- E21B 21/08: Controlling or monitoring pressure or flow of drilling fluid, e.g. automatic filling of boreholes, automatic control of bottom pressure (valve arrangements therefor E21B21/10)
- E21B 47/11: using tracers; using radioactivity
- C09K 2211/1014: bridged by heteroatoms, e.g. N, P, Si or B
- C09K 2211/1018: Heterocyclic compounds
- C09K: MATERIALS FOR MISCELLANEOUS APPLICATIONS, NOT PROVIDED FOR ELSEWHERE
- C09B: ORGANIC DYES OR CLOSELY-RELATED COMPOUNDS FOR PRODUCING DYES {, e.g. PIGMENTS}; MORDANTS; LAKES (fermentation or enzyme using processes to synthesise a desired chemical compound C12P)
- E21B: EARTH OR ROCK DRILLING; OBTAINING OIL, GAS, WATER, SOLUBLE OR MELTABLE MATERIALS OR A SLURRY OF MINERALS FROM WELLS

## Abstract

A composition includes a functionalized fluorescent dye. The functionalized fluorescent dye includes an isothiocyanate-containing dye that is functionalized with a functional group. The functional group includes a primary amine. The functionalized fluorescent dye can be mixed with a fluid to form a tracer fluid for tracing fluid flow in a subterranean formation.

## Claims

### Claim 1

A method of making a functionalized fluorescent dye, comprising:
dissolving a water-soluble isothiocyanate-containing fluorescent dye in an aqueous solvent to yield an aqueous dye solution, wherein the water-soluble isothiocyanate-containing fluorescent dye is selected from the group consisting of fluorescein isothiocyanate, Rhodamine B isothiocyanate, or tetramethylrhodamine isothiocyanate, or any isoform thereof;
dissolving a functional group in water to yield an aqueous functional group solution, wherein the functional group comprises a primary amine and is selected from Group I or Group II, wherein:
Group I consists of aminomethanesulfonic acid, 2-aminoethanesulfonic acid, 3-amino-1-propanesulfonic acid, 2-aminoethyl(trimethyl)azanium, and 3-aminopropyl(trimethyl)azanium; and
Group II consists of 4-aminobenzenesulfonic acid, 3-aminobenzenesulfonic acid, 2-aminobenzenesulfonic acid, 3-amino-4-hydroxybenzenesulfonic acid, 4-amino-3-hydroxybenzenesulfonic acid, (4-aminophenyl)-trimethylazanium, 6-amino-4-hydroxy-2-naphthalenesulfonic acid, 4-amino-3-hydroxy-1-naphthalenesulfonic acid, 7-aminonaphthalene-1,3-disulfonic acid, 4-aminonaphthalene-1,7-disulfonic acid, 8-amino-1,3,6-naphthalenetrisulfonic acid, and 8-aminopyrene-1,3,6-trisulfonic acid; and
mixing the aqueous dye solution and the aqueous functional group solution to form the functionalized fluorescent dye, wherein the functionalized fluorescent dye is a reaction product of the water-soluble isothiocyanate-containing dye and the functional group.

### Claim 2 (depends on 1)

The method of claim 1, wherein the aqueous solvent is a mixture of water and ethanol.

### Claim 3 (depends on 2)

The method of claim 2, wherein a volumetric ratio of water to ethanol of the aqueous solvent is in a range of from 1:1 to 9:1.

### Claim 4 (depends on 1)

The method of claim 1, wherein the water is deionized water.

### Claim 5

A method of tracing fluid flow in a subterranean formation, comprising:
mixing a functionalized fluorescent tracer and a fluid to yield a tracer fluid, wherein the functionalized fluorescent tracer comprises an isothiocyanate-containing dye functionalized with a functional group comprising a primary amine, wherein:
the isothiocyanate-containing dye is selected from the group consisting of fluorescein isothiocyanate, Rhodamine B isothiocyanate, or tetramethylrhodamine isothiocyanate, or any isoform thereof; and
the functional group is selected from Group I or Group II, wherein:
Group I consists of aminomethanesulfonic acid, 2-aminoethanesulfonic acid, 3-amino-1-propanesulfonic acid, 2-aminoethyl(trimethyl)azanium, and 3-aminopropyl(trimethyl)azanium; and
Group II consists of 4-aminobenzenesulfonic acid, 3-aminobenzenesulfonic acid, 2-aminobenzenesulfonic acid, 3-amino-4-hydroxybenzenesulfonic acid, 4-amino-3-hydroxybenzenesulfonic acid, (4-aminophenyl)-trimethylazanium, 6-amino-4-hydroxy-2-naphthalenesulfonic acid, 4-amino-3-hydroxy-1-naphthalenesulfonic acid, 7-aminonaphthalene-1,3-disulfonic acid, 4-aminonaphthalene-1,7-disulfonic acid, 8-amino-1,3,6-naphthalenetrisulfonic acid, and 8-aminopyrene-1,3,6-trisulfonic acid;
flowing the tracer fluid into a first subterranean formation;
recovering a sample from the first subterranean formation or a second subterranean formation connected to the first subterranean formation; and
analyzing the sample for a fluorescent signal.

### Claim 6 (depends on 5)

The method of claim 5, comprising identifying the functionalized fluorescent tracer in the sample using fluorescence imaging, fluorescence spectroscopy, ultraviolet-visible (UV-Vis) spectroscopy, Fourier-transform infrared spectroscopy (FTIR), Raman spectroscopy, mass spectroscopy (MS), high performance liquid chromatography (HPLC), liquid chromatography-mass spectroscopy (LC-MS), or pyrolysis gas chromatography-mass spectroscopy (pyrolysis GC-MS), or any combination thereof.

### Claim 7 (depends on 5)

The method of claim 5, where in the sample is a fluid sample.

### Claim 8 (depends on 5)

The method of claim 5, wherein the fluid is a fracking fluid.

### Claim 9 (depends on 5)

The method of claim 5, wherein the fluid is a drilling mud.