# US 10,119,072 B2 · Carbon-based fluorescent tracers as oil reservoir nano-agents

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- Number: US 10,119,072 B2
- Document ID: US10119072B2
- Status: Granted
- Kind: B2
- Application number: 15/266,451
- Filed: 2016-09-15
- Published: 2017-01-05
- Granted: 2018-11-06
- Earliest claimed: 2011-05-13
- Assignees: Saudi Arabian Oil Company; Cornell University
- Applicants: Saudi Arabian Oil Company; Cornell University
- Inventors: Mazen Y. Kanj; Mohammad Harunar Rashid; Emmanuel Giannelis
- Web page: https://patentgrep.com/patent/US10119072B2

## CPC

- C09K 11/06: containing organic luminescent materials
- B82Y 20/00: Nanooptics, e.g. quantum optics or photonic crystals
- C01B 32/15: Nano-sized carbon materials
- C07C 215/08: with only one hydroxy group and one amino group bound to the carbon skeleton
- C07C 227/18: by reactions involving amino or carboxyl groups, e.g. hydrolysis of esters or amides, by formation of halides, salts or esters
- C07C 231/02: from carboxylic acids or from esters, anhydrides, or halides thereof by reaction with ammonia or amines
- C07C 235/74: of a saturated carbon skeleton
- C07H 15/04: attached to an oxygen atom of the saccharide radical
- C09K 9/02: Organic tenebrescent materials
- C09K 11/65: containing carbon (in organic compounds C09K11/06)
- E21B 47/11: using tracers; using radioactivity
- E21B 49/00: Testing the nature of borehole walls; Formation testing; Methods or apparatus for obtaining samples of soil or well fluids, specially adapted to earth drilling or wells
- E21B 49/008: {by injection test; by analysing pressure variations in an injection or production test, e.g. for estimating the skin factor (measuring pressure E21B47/06)}
- B82Y 40/00: Manufacture or treatment of nanostructures
- C09K 2208/10: Nanoparticle-containing well treatment fluids
- C09K 2211/10: Non-macromolecular compounds
- Y10S 977/773: Nanoparticle, i.e. structure having three dimensions of 100 nm or less
- Y10S 977/774: Exhibiting three-dimensional carrier confinement, e.g. quantum dots
- Y10S 977/896: Chemical synthesis, e.g. chemical bonding or breaking
- Y10S 977/95: Electromagnetic energy
- Y10T 428/2982: Particulate matter [e.g., sphere, flake, etc.]
- C09K: MATERIALS FOR MISCELLANEOUS APPLICATIONS, NOT PROVIDED FOR ELSEWHERE
- B82Y: SPECIFIC USES OR APPLICATIONS OF NANOSTRUCTURES; MEASUREMENT OR ANALYSIS OF NANOSTRUCTURES; MANUFACTURE OR TREATMENT OF NANOSTRUCTURES
- C01B: NON-METALLIC ELEMENTS; COMPOUNDS THEREOF; {METALLOIDS OR COMPOUNDS THEREOF NOT COVERED BY SUBCLASS C01C}
- C07C: ACYCLIC OR CARBOCYCLIC COMPOUNDS
- C07H: SUGARS; DERIVATIVES THEREOF; NUCLEOSIDES; NUCLEOTIDES; NUCLEIC ACIDS (derivatives of aldonic or saccharic acids C07C, C07D; aldonic acids, saccharic acids C07C59/105, C07C59/285; cyanohydrins C07C255/16; glycals C07D; compounds of unknown constitution C07G; polysaccharides, derivatives thereof C08B; DNA or RNA concerning genetic engineering, vectors, e.g. plasmids, or their isolation, preparation or purification C12N15/00; sugar industry C13)
- E21B: EARTH OR ROCK DRILLING; OBTAINING OIL, GAS, WATER, SOLUBLE OR MELTABLE MATERIALS OR A SLURRY OF MINERALS FROM WELLS
- Y10S: TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y10T: TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION

## Abstract

The present invention relates to carbon-based fluorescent nano-agent tracers for analysis of oil reservoirs. The carbon-based fluorescent nano-agents may be used in the analysis of the porosity of a formation. The nanoagents are suitable for injection into a petroleum reservoir and may be recovered from the reservoir for the determination of hydrocarbon flow rates and retention times.

## Claims

### Claim 1

A method for the preparation of a fluorescent nanoagent for use in a subsurface petroleum reservoir, the method comprising the steps of:
heating an aqueous solution comprising sugar under high pressure at a temperature of at least 150° C. for at least 4 hours;
adding an amino alcohol to the solution and refluxing the resulting mixture for a period of at least 10 hours;
purifying a solid product by dialysis in water using a cellulose membrane having a molecular weight cut-off of 7000 daltons;
collecting the solid product comprising carbon-based nanoparticles having fluorescent functional groups attached to the surface thereof, the carbon-based nanoparticles having an average diameter between 10 nm and 50 nm.

### Claim 2 (depends on 1)

The method of claim 1, wherein the sugar is selected from glucose and fructose.

### Claim 3 (depends on 1)

The method of claim 1, wherein the amino alcohol is selected from methanolamine, ethanolamine, and propanolamine.

### Claim 4 (depends on 1)

The method of claim 1, wherein the amino alcohol is ethanolamine.

### Claim 5 (depends on 1)

The method of claim 1, wherein the fluorescent nanoagent is produced from a solution comprising glucose, ethanolamine and deionized water reacted under conditions capable of synthesizing the fluorescent nanoagent.

### Claim 6 (depends on 1)

The method of claim 1, wherein the fluorescent nanoagent is stable at a temperature of 100° C. to 200° C.

### Claim 7 (depends on 1)

The method of claim 1, wherein the fluorescent nanoagent is stable at a salinity concentration of 75,000 ppm to 120,000 ppm.

### Claim 8 (depends on 1)

The method of claim 1, wherein the fluorescent functional groups can be excited at a wavelength between 400 nm and 500 nm.

### Claim 9

A method for the preparation of a fluorescent nanoagent for use in a subsurface petroleum reservoir, the method comprising the steps of:
heating an aqueous solution comprising glucose under high pressure at a temperature of at least 150° C. for at least 4 hours;
adding ethanolamine to the solution and refluxing the resulting mixture for a period of at least 10 hours;
purifying a solid product by dialysis in water using a cellulose membrane having a molecular weight cut-off of 7000 daltons;
collecting the solid product comprising A-NP carbon nanoparticles having fluorescent functional groups attached to the surface thereof.

### Claim 10 (depends on 9)

The method of claim 9, wherein the A-NP carbon nanoparticles have an average diameter between 30 nm and 50 nm.