# US 11,111,428 B2 · Thermally-stable, non-precipitating, high-density wellbore fluids

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- Number: US 11,111,428 B2
- Document ID: US11111428B2
- Status: Granted
- Kind: B2
- Application number: 16/571,961
- Filed: 2019-09-16
- Published: 2020-01-09
- Granted: 2021-09-07
- Earliest claimed: 2019-09-16
- Assignees: Halliburton Energy Services, Inc.
- Applicants: Halliburton Energy Services, Inc.
- Inventors: Cato R. McDaniel; William W. Shumway; Timothy Harvey
- Web page: https://patentgrep.com/patent/US11111428B2

## CPC

- C09K 8/665: {containing inorganic compounds (proppants C09K8/80)}
- C09K 8/02: Well-drilling compositions
- C09K 8/05: containing inorganic compounds only, e.g. mixtures of clay and salt
- C09K 8/40: Spacer compositions, e.g. compositions used to separate well-drilling from cementing masses
- C09K 8/60: Compositions for stimulating production by acting on the underground formation
- C09K 8/845: {containing inorganic compounds}
- C09K: MATERIALS FOR MISCELLANEOUS APPLICATIONS, NOT PROVIDED FOR ELSEWHERE

## Abstract

A wellbore treatment fluid comprising: a base fluid; and a water-soluble salt, the salt comprising: a cation; and an anion, wherein the anion is selected from phosphotungstate, silicotungstate, phosphomolybdate, and silicomolybdate. The treatment fluid can have a density greater than or equal to 13 pounds per gallon. A method of treating a portion of a subterranean formation penetrated by a well comprising: introducing the treatment fluid into the well.

## Claims

### Claim 1

A system comprising:
a wellbore that penetrates a subterranean formation; and
a treatment fluid comprising:
(A) a base fluid; and
(B) a water-soluble salt, the salt comprising:
(i) a cation selected from ammonium, phosphonium, quaternary amines, poly-quaternary amines, and rare earth metals; and
(ii) an anion, wherein the anion is selected from phosphotungstate, silicotungstate, and silicomolybdate.

### Claim 2 (depends on 1)

The system of claim 1, wherein the base fluid comprises water, and wherein the water is selected from the group consisting of freshwater, brackish water, saltwater, and any combination thereof.

### Claim 3 (depends on 1)

The system of claim 1, wherein the cation is organic or inorganic.

### Claim 4 (depends on 1)

The system of claim 1, wherein the treatment fluid is thermally stable at temperatures greater than 212 ° F.

### Claim 5 (depends on 1)

The system of claim 1, wherein the treatment fluid is a drilling fluid, a drill-in fluid, a packer fluid, a completion fluid, a spacer fluid, a work-over fluid, or an insulating fluid.

### Claim 6 (depends on 1)

The system of claim 1, further comprising a mixer, wherein the mixer is capable of mixing the treatment fluid.

### Claim 7 (depends on 1)

The system of claim 1, further comprising a pump capable of pumping the treatment fluid into the subterranean formation.

### Claim 8 (depends on 1)

The system of claim 1, wherein the treatment fluid further comprises an additional additive selected from the group consisting of a fluid loss additive, a bridging agent, a friction reducer, a defoaming agent, elastomers, a mechanical property enhancing additive, a lost-circulation material, a filtration-control additive, a gas migration control additive, a thixotropic additive, a viscosifying additive, and combinations thereof.

### Claim 9 (depends on 1)

The system of claim 1, wherein the subterranean formation has a bottomhole temperature greater than 212 ° F.

### Claim 10

A wellbore treatment fluid comprising:
a base fluid; and
a water-soluble salt, the salt comprising:
a cation selected from ammonium, phosphonium, quaternary amines, poly-quaternary amines, and rare earth metals; and
an anion, wherein the anion is selected from phosphotungstate, silicotungstate, and silicomolybdate.

### Claim 11 (depends on 10)

The fluid of claim 10, wherein the base fluid comprises water, and wherein the water is selected from the group consisting of freshwater, brackish water, saltwater, and any combination thereof.

### Claim 12 (depends on 10)

The fluid of claim 10, wherein the treatment fluid has a density greater than or equal to 13 pounds per gallon.

### Claim 13 (depends on 10)

The fluid of claim 10, wherein the cation is organic or inorganic.

### Claim 14 (depends on 10)

The fluid of claim 10, wherein the type of salt and the concentration of the salt are selected, based on the mass of the salt and the solubility of the salt, to provide a density of at least 13 pounds per gallon to the treatment fluid.

### Claim 15 (depends on 10)

The fluid of claim 10, further comprising an additional salt.

### Claim 16 (depends on 15)

The fluid of claim 15, wherein the additional salt is selected from the group consisting of sodium chloride, calcium chloride, calcium bromide, potassium chloride, potassium bromide, magnesium chloride, and any combinations thereof.

### Claim 17 (depends on 10)

The fluid of claim 10, further comprising an additional additive selected from the group consisting of a fluid loss additive, a bridging agent, a friction reducer, a defoaming agent, elastomers, a mechanical property enhancing additive, a lost-circulation material, a filtration-control additive, a gas migration control additive, a thixotropic additive, a viscosifying additive, and combinations thereof.

### Claim 18 (depends on 10)

The fluid of claim 10, wherein the treatment fluid is thermally stable at temperatures greater than 212 ° F.

### Claim 19 (depends on 1)

The system of claim 1, wherein the treatment fluid is thermally stable at temperatures greater than 350 ° F.

### Claim 20 (depends on 11)

The fluid of claim 11, wherein the treatment fluid is thermally stable at temperatures greater than 350 ° F.