# US 11,441,069 B2 · Method for improving aquifer remediation using in-situ generated nitrogen foam

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- Number: US 11,441,069 B2
- Document ID: US11441069B2
- Status: Granted
- Kind: B2
- Application number: 16/937,959
- Filed: 2020-07-24
- Published: 2022-01-27
- Granted: 2022-09-13
- Earliest claimed: 2020-07-24
- Assignees: Saudi Arabian Oil Company
- Applicants: Saudi Arabian Oil Company
- Inventors: Zuhair AlYousif; Ali Abdullah Al-Taq
- Web page: https://patentgrep.com/patent/US11441069B2

## CPC

- B09C 1/002: {involving in-situ ground water treatment}
- C09K 8/94: Foams
- B09C 1/08: chemically
- C08J 9/10: developing nitrogen {, the blowing agent being a compound containing a nitrogen-to-nitrogen bond}
- B09C 2101/00: In situ
- C02F 2103/06: Contaminated groundwater or leachate
- C02F 2305/04: Surfactants, used as part of a formulation or alone
- C08J 2203/04: N2 releasing, ex azodicarbonamide or nitroso compound
- C08J 2207/12: Sanitary use, e.g. diapers, napkins or bandages
- B09C: RECLAMATION OF CONTAMINATED SOIL (gatherers for removing stone or the like from the soil A01B43/00; sterilising soil by steam A01G11/00; removing undesirable matter, e.g. rubbish, from the land E01H15/00)
- C09K: MATERIALS FOR MISCELLANEOUS APPLICATIONS, NOT PROVIDED FOR ELSEWHERE
- C08J: WORKING-UP; GENERAL PROCESSES OF COMPOUNDING; AFTER-TREATMENT NOT COVERED BY SUBCLASSES C08B, C08C, C08F, C08G or C08H (working, e.g. shaping, of plastics B29)
- C02F: TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE (separation in general B01D; special arrangements on waterborne vessels of installations for treating water, waste water or sewage, e.g. for producing fresh water, B63J; adding materials to water to prevent corrosion C23F; treating radioactively-contaminated liquids G21F9/04; regeneration of reactants for recirculation into processes, see the relevant places for the processes)

## Abstract

A method of remediation of a water-bearing formation is disclosed. A first solution containing a nitrogen-containing compound and a second solution containing a nitrite-containing compound are introduced into the water-bearing formation. The two solutions intermix within the formation such that a foam is generated within the formation.

## Claims

### Claim 1

A method for remediation of a water-bearing formation comprising the steps of:
introducing a first aqueous solution and a second aqueous solution into the water-bearing formation such that the first aqueous solution and the second aqueous solution intermix within the water-bearing formation; and
maintaining the intermixed solution in the water-bearing formation such that a foam is generated in situ;
where the intermixed solution comprises a foaming agent;
where the first aqueous solution comprises a nitrogen-containing compound and an acid;
where the second aqueous solution comprises a nitrite-containing compound;
where the concentration of the acid in the first aqueous solution is such that the pH of the intermixed solution in the water-bearing formation is at or less than about 4.5; and
where the apparent viscosity of the foam generated in the water-bearing formation is in a range of from about 10 times to about 1000 times greater than an apparent viscosity of an aquifer remediation fluid as measured at 60° C. at a low shear rate in a range of from about 10 to about 50 RPM.

### Claim 2 (depends on 1)

The method of claim 1 where the nitrogen-containing compound is selected from the group consisting of an ammonium-containing compound, a primary amine-containing compound, and combinations thereof.

### Claim 3 (depends on 2)

The method of claim 2 where the ammonium-containing compound is selected from the group consisting of ammonium hydroxide, ammonium chloride, ammonium bromide, ammonium nitrate, ammonium nitrite, ammonium acetate, ammonium formate, ammonium sulfate, and ammonium carbonate.

### Claim 4 (depends on 2)

The method of claim 2, where the primary amine-containing compound is selected from the group consisting of ethylene diamine, formamide, acetamide, urea, benzyl urea, butyl urea, hydrazine, phenylhydrazine, and phenylhydrazine hydro-chloride.

### Claim 5 (depends on 1)

The method of claim 1 where the nitrite-containing compound is selected from the group consisting of ammonium nitrite, calcium nitrite, sodium nitrite, potassium nitrate, and combinations thereof.

### Claim 6 (depends on 1)

The method of claim 1 where the first aqueous solution and the second aqueous solution are introduced into the formation separately.

### Claim 7 (depends on 6)

The method of claim 6 where the first aqueous solution and the second aqueous solution are introduced into the formation simultaneously and separately.

### Claim 8 (depends on 1)

The method of claim 1 where the first aqueous solution is introduced into the water-bearing formation at a temperature less than the temperature of the water-bearing formation.

### Claim 9 (depends on 1)

The method of claim 1 where the second aqueous solution is introduced into the formation at a temperature less than the temperature of the water-bearing formation.

### Claim 10 (depends on 1)

The method of claim 1, where the temperature in which the first aqueous solution is introduced is such that the temperature of the intermixed solution in the water-bearing formation is from about 60° C. to about 110° C.

### Claim 11 (depends on 1)

The method of claim 1, where the temperature in which the second aqueous solution is introduced is such that the temperature of the intermixed solution in the water-bearing formation is from about 60° C. to about 110° C.

### Claim 12 (depends on 1)

The method of claim 1 where a molar ratio of a concentration of the nitrogen-containing compound in the first aqueous solution and a concentration of the nitrite-containing compound in the second aqueous solution is in a range of about 1:1 to about 1:2.

### Claim 13 (depends on 1)

The method of claim 1 where a volume ratio of the first aqueous solution to the second aqueous solution is about 1:1.

### Claim 14 (depends on 1)

The method of claim 1, where the acid is selected from the group consisting of hydrochloric acid, citric acid, propionic acid, benzoic acid, formic acid, acetic acid, and combinations thereof.

### Claim 15 (depends on 1)

The method of claim 1, where the first aqueous solution further comprises an acid buffer, and where the acid is hydrochloric acid.

### Claim 16 (depends on 1)

The method of claim 1 where the foam quality of the foam generated in situ is in a range of from about 50% to about 99%.

### Claim 17 (depends on 1)

The method of claim 1, further comprising introducing the aquifer remediation fluid into the water-bearing formation after the generation of the foam.