# US 11,898,085 B2 · Downhole fluids and methods of use thereof

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- Number: US 11,898,085 B2
- Document ID: US11898085B2
- Status: Granted
- Kind: B2
- Application number: 17/494,030
- Filed: 2021-10-05
- Published: 2022-03-17
- Granted: 2024-02-13
- Earliest claimed: 2019-09-06
- Assignees: Halliburton Energy Services, Inc.
- Applicants: Halliburton Energy Services, Inc.
- Inventors: Vivek S. Goel; Peter James Boul; Xueyu Pang; Lee J. Hall; Jay P. Deville; Samuel J. Lewis; B. Raghava Reddy; Trissa Joseph; Xiangnan Ye
- Web page: https://patentgrep.com/patent/US11898085B2

## CPC

- C09K 8/206: {Derivatives of other natural products, e.g. cellulose, starch, sugars}
- C04B 22/0093: {Aluminates}
- C04B 22/10: containing carbon in the anion, e.g. carbonates
- C04B 24/383: {Cellulose or derivatives thereof}
- C04B 28/02: containing hydraulic cements other than calcium sulfates
- C04B 28/04: Portland cements
- C09K 8/145: {characterised by the composition of the clay}
- C09K 8/16: characterised by the inorganic compounds other than clay
- C09K 8/40: Spacer compositions, e.g. compositions used to separate well-drilling from cementing masses
- C09K 8/467: containing additives for specific purposes
- C09K 8/487: Fluid loss control additives; Additives for reducing or preventing circulation loss
- C09K 8/493: Additives for reducing or preventing gas migration
- C09K 8/54: Compositions for in situ inhibition of corrosion in boreholes or wells
- C09K 8/80: Compositions for reinforcing fractures, e.g. compositions of proppants used to keep the fractures open
- C04B 2103/46: Water-loss or fluid-loss reducers, hygroscopic or hydrophilic agents, water retention agents
- C09K 8/504: Compositions based on water or polar solvents (C09K8/502 takes precedence)
- C09K 2208/10: Nanoparticle-containing well treatment fluids
- C09K 2208/32: Anticorrosion additives
- C09K 2208/34: Lubricant additives
- C09K: MATERIALS FOR MISCELLANEOUS APPLICATIONS, NOT PROVIDED FOR ELSEWHERE
- C04B: LIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE {(roofing granules E04D7/005)}; CERAMICS (devitrified glass-ceramics C03C10/00); REFRACTORIES; TREATMENT OF NATURAL STONE

## Abstract

The present disclosure relates to downhole fluid additives including a clay, a hydroxylated polymer, a cation, and water. The disclosure further relates to downhole fluids, including drilling fluids, spaces, cements, and proppant delivery fluids containing such as downhole fluid additive and methods of using such fluids. The downhole fluid additive may have any of a variety of functions in the downhole fluid and may confer any of a variety of properties upon it, such as salt tolerance or desired viscosities even at high downhole temperatures.

## Claims

### Claim 1

A spacer, comprising:
a clay comprising a smectite clay;
a hydroxylated polymer, wherein the a hydroxylated polymer comprises microfibrillated cellulose (MFC);
a cation;
the clay, the hydroxylated polymer, and the cation together in an amount sufficient to render the downhole fluid thermally stable at a temperature of 400° F.; and
at least one additional downhole fluid component.

### Claim 2 (depends on 1)

The spacer of claim 1, further comprising salt water.

### Claim 3 (depends on 1)

The spacer of claim 1, further comprising a surfactant, a defoamer, a salt, a viscosifier or any combinations thereof.

### Claim 4 (depends on 3)

The spacer of claim 3, wherein the salt comprises sodium chloride or calcium chloride.

### Claim 5 (depends on 3)

The spacer of claim 3, wherein the viscosifier comprises nanoparticles of 100 nm or less in size.

### Claim 6 (depends on 1)

The spacer of claim 1, wherein the at least one additional downhole fluid component is an aqueous component with a pH of at least 9.

### Claim 7 (depends on 1)

The spacer of claim 1, wherein the spacer has a transition temperature of around 150° F. at which viscosity rapidly increases.

### Claim 8 (depends on 1)

The spacer of claim 1, wherein the hydroxylated polymer comprises microcellulose or nanocellulose.

### Claim 9

A method for introducing a spacer into a subterranean formation, the method comprising:
providing a spacer comprising:
a clay, wherein the clay comprises a smectite clay;
a hydroxylated polymer, wherein the a hydroxylated polymer comprises microfibrillated cellulose (MFC);
a cation;
the clay, the hydroxylated polymer, and the cation together in an amount sufficient to render the downhole fluid thermally stable at a temperature of 400° F.; and
at least one additional downhole fluid component-; and
pumping the spacer into the interior of a casing or a wellbore annulus in a wellbore in the subterranean formation to displace fluid remaining in the wellbore.

### Claim 10 (depends on 9)

The method of claim 9, wherein the spacer further comprises salt water.

### Claim 11 (depends on 9)

The method of claim 9, wherein the spacer further comprises a surfactant, a defoamer, a salt, a viscosifier or any combinations thereof.

### Claim 12 (depends on 11)

The method of claim 11, wherein the salt comprises sodium chloride or calcium chloride.

### Claim 13 (depends on 11)

The method of claim 11, wherein the viscosifier comprises nanoparticles of 100 nm or less in size.

### Claim 14 (depends on 9)

The method of claim 9, wherein the at least one additional downhole fluid component is an aqueous component with a pH of at least 11.

### Claim 15 (depends on 9)

The method of claim 9, wherein the spacer has a transition temperature of around 150° F. at which viscosity rapidly increases.

### Claim 16 (depends on 9)

The method of claim 9, wherein the hydroxylated polymer comprises microcellulose or nanocellulose.

### Claim 17 (depends on 1)

The spacer of claim 1, wherein the MFC comprise cellulose fibers with a diameter between 5 nanometers (nm) and 60 nm and a length of 2 to 10 micrometers (μm).

### Claim 18 (depends on 17)

The spacer of claim 17, wherein the MFC comprises cellulose nanofibrils, microfibrils, or a combination thereof.

### Claim 19 (depends on 9)

The method of claim 9, wherein the MFC comprise cellulose fibers with a diameter between 5 nanometers (nm) and 60 nm and a length of 2 to 10 micrometers (μm).

### Claim 20 (depends on 19)

The method of claim 19, wherein the MFC comprises cellulose nanofibrils, microfibrils, or a combination thereof.