# US 11,993,746 B2 · Method of waterflooding using injection solutions containing dihydrogen phosphate

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- Number: US 11,993,746 B2
- Document ID: US11993746B2
- Status: Granted
- Kind: B2
- Application number: 17/956,569
- Filed: 2022-09-29
- Published: 2024-04-04
- Granted: 2024-05-28
- Earliest claimed: 2022-09-29
- Assignees: Saudi Arabian Oil Company
- Applicants: Saudi Arabian Oil Company
- Inventors: Moataz Abu Al Saud; Salem Khaled Al-Shammari; Hussain Habib Al Saleem; Salah Hamad Al-Saleh; Subhash Ayirala; Ali Yousef
- Web page: https://patentgrep.com/patent/US11993746B2

## CPC

- C09K 8/58: Compositions for enhanced recovery methods for obtaining hydrocarbons, i.e. for improving the mobility of the oil, e.g. displacing fluids
- E21B 43/20: Displacing by water
- C09K 8/845: {containing inorganic compounds}
- 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

Provided are methods of increasing the production of a hydrocarbon from a subterranean formation by waterflooding with injection solutions containing dihydrogen phosphate ions.

## Claims

### Claim 1

A method of waterflooding, comprising:
introducing a first injection solution comprising about 400 ppm to about 1000 ppm of dihydrogen phosphate ions into a subterranean formation; and
introducing a second injection solution comprising dihydrogen phosphate ions into the subterranean formation;
wherein the second injection solution has a concentration of dihydrogen phosphate ions of about 200 ppm to about 800 ppm, and a concentration of dihydrogen phosphate ions of at least about 200 ppm less than the first injection solution; and
wherein at least a portion of a hydrocarbon present in the subterranean formation is displaced.

### Claim 2 (depends on 1)

The method of claim 1, wherein at least one of the following holds:
the first injection solution has a pH of about 5.0 to about 5.5; or
the second injection solution has a pH of about 5.0 to about 5.5.

### Claim 3 (depends on 1)

The method of claim 1, wherein at least one of the following holds:
the first injection solution comprises seawater; or
the second injection solution comprises seawater.

### Claim 4 (depends on 1)

The method of claim 1, wherein at least one of the following holds:
an amount of the first injection solution introduced into the subterranean formation is about 0.3 to about 0.5 pore volumes; or
an amount of the second injection solution introduced into the subterranean formation is about 0.3 to about 0.5 pore volumes.

### Claim 5 (depends on 1)

The method of claim 1, wherein the first injection solution comprises about 1000 ppm of dihydrogen phosphate ions.

### Claim 6 (depends on 5)

The method of claim 5, wherein at least one of the following holds:
the first injection solution comprises seawater; or
the second injection solution comprises seawater.

### Claim 7 (depends on 1)

The method of claim 1, further comprising introducing a chase solution, comprising aquifer water, surface water, seawater, or combinations thereof, into the subterranean formation.

### Claim 8 (depends on 7)

The method of claim 7, wherein an amount of the chase solution introduced into the subterranean formation is about 0.5 to about 1.0 pore volumes.

### Claim 9 (depends on 1)

The method of claim 1, wherein the subterranean formation comprises a carbonate formation.

### Claim 10 (depends on 1)

The method of claim 1, wherein the first injection solution is introduced after primary production of a hydrocarbon from the subterranean formation.

### Claim 11 (depends on 1)

The method of claim 1, further comprising producing the hydrocarbon from the subterranean formation.

### Claim 12

A method of waterflooding, comprising:
introducing a first injection solution comprising about 1000 ppm of dihydrogen phosphate ions into a subterranean formation;
introducing a second injection solution comprising about 800 ppm of dihydrogen phosphate ions into the subterranean formation;
introducing a third injection solution comprising about 600 ppm of dihydrogen phosphate ions into the subterranean formation;
introducing a fourth injection solution comprising about 400 ppm of dihydrogen phosphate ions into the subterranean formation; and
introducing a fifth injection solution comprising about 200 ppm of dihydrogen phosphate ions into the subterranean formation,
wherein at least one of the first injection solution, the second injection solution, the third injection solution, the fourth injection solution, and the fifth injection solution displaces at least a portion of a hydrocarbon present in the subterranean formation.

### Claim 13 (depends on 12)

The method of claim 12, wherein at least one of the first injection solution, the second injection solution, the third injection solution, the fourth injection solution, and the fifth injection solution has a pH of about 5.0 to about 5.5.

### Claim 14 (depends on 12)

The method of claim 12, wherein at least one of the first injection solution, the second injection solution, the third injection solution, the fourth injection solution, and the fifth injection solution comprises seawater.

### Claim 15 (depends on 12)

The method of claim 12, wherein an amount of at least one of the first injection solution, the second injection solution, the third injection solution, the fourth injection solution, and the fifth injection solution introduced into the subterranean formation is about 0.3 to about 0.5 pore volumes.

### Claim 16 (depends on 12)

The method of claim 12, further comprising injecting a chase solution, comprising aquifer water, surface water, seawater, or combinations thereof, into the subterranean formation.

### Claim 17 (depends on 16)

The method of claim 16, wherein an amount of the chase solution introduced into the subterranean formation is about 0.5 to about 1.0 pore volumes.

### Claim 18 (depends on 12)

The method of claim 12, wherein the subterranean formation comprises a carbonate formation.

### Claim 19 (depends on 12)

The method of claim 12, wherein the first injection solution is introduced after primary production of a hydrocarbon from the subterranean formation.

### Claim 20 (depends on 12)

The method of claim 12, further comprising producing the hydrocarbon from the subterranean formation.