# US 11,299,662 B2 · Method to use lost circulation material composition comprising alkaline nanoparticle based dispersion and sodium bicarbonate in downhole conditions

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- Number: US 11,299,662 B2
- Document ID: US11299662B2
- Status: Granted
- Kind: B2
- Application number: 16/922,512
- Filed: 2020-07-07
- Published: 2022-01-13
- Granted: 2022-04-12
- Earliest claimed: 2020-07-07
- Assignees: Saudi Arabian Oil Company
- Applicants: Saudi Arabian Oil Company
- Inventors: Vikrant Wagle; Rajendra Arunkumar Kalgaonkar; Abdullah Al-Yami; Sara Alkhalaf
- Web page: https://patentgrep.com/patent/US11299662B2

## CPC

- C09K 8/5045: {containing inorganic compounds}
- C04B 28/24: containing alkyl, ammonium or metal silicates; containing silica sols {(reaction mixtures resulting in mineral polymers C04B28/006; polymeric reaction products of alkali metal silicates with isocyanates C08G18/3895)}
- C09K 8/516: characterised by their form or by the form of their components, e.g. encapsulated material
- C09K 2208/10: Nanoparticle-containing well treatment fluids
- 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

Provided is a lost circulation material that may consist essentially of an alkaline nanosilica dispersion and a sodium bicarbonate activator. Further provided are methods that may control lost circulation in a lost circulation zone in a wellbore by introducing the lost circulation material such that it contacts the lost circulation zone and forms a gelled solid in the lost circulation zone.

## Claims

### Claim 1

A lost circulation material, consisting essentially of:
a lost circulation material gel that is (a) and (b) in combination, where
(a) is an alkaline nanosilica dispersion,
wherein the alkaline nanosilica dispersion comprises 30-50 wt % of alkaline silica nanoparticles, and
(b) is a sodium bicarbonate activator,
wherein the sodium bicarbonate activator is present in an amount in a range of 19 wt % to 40 wt % of the lost circulation material.

### Claim 2 (depends on 1)

The lost circulation material of claim 1, wherein the alkaline nanosilica dispersion comprises alkaline silica nanoparticles having a size in a range from about 10 nm to about 70 nm.

### Claim 3 (depends on 1)

The lost circulation material of claim 1, wherein the alkaline nanosilica dispersion comprises alkaline silica nanoparticles having a size in a range from about 40 nm to about 50 nm.

### Claim 4 (depends on 1)

The lost circulation material of claim 1, wherein a weight ratio of the sodium bicarbonate activator to the alkaline silica nanoparticles is in a range from about 1:1 to about 1:3.

### Claim 5 (depends on 1)

The lost circulation material of claim 1, wherein the alkaline nanosilica dispersion has a pH in a range from 9.5 to 10.5, and wherein the alkaline nanosilica dispersion is in the absence of sodium silicate.

### Claim 6 (depends on 1)

The lost circulation material of claim 1, wherein the sodium bicarbonate activator is present in an amount in a range of 19 wt % to 35 wt %.

### Claim 7 (depends on 1)

The lost circulation material of claim 1, wherein the sodium bicarbonate activator is present in an amount in a range of 20 wt % to 35 wt %.

### Claim 8

A method of controlling lost circulation in a lost circulation zone in a wellbore, comprising:
introducing a lost circulation material consisting essentially of an alkaline nanosilica dispersion and a sodium bicarbonate activator into the wellbore such that they contact the lost circulation zone,
wherein the alkaline nanosilica dispersion comprises 30-50 wt % of alkaline silica nanoparticles,
wherein the sodium bicarbonate activator is present in an amount in a range of 19 wt % to 40 wt % of the lost circulation material,
wherein the alkaline nanosilica dispersion and the sodium bicarbonate activator are not premixed, and
forming a gelled solid from the lost circulation material in the lost circulation zone.

### Claim 9 (depends on 8)

The method of claim 8, wherein formation of the gelled solid occurs within 6-24 hours.

### Claim 10 (depends on 8)

The method of claim 8, wherein the alkaline nanosilica dispersion comprises alkaline silica nanoparticles having a size in a range from about 10 nm to about 70 nm.

### Claim 11 (depends on 8)

The method of claim 8, wherein a weight ratio of the sodium bicarbonate activator to the alkaline silica nanoparticles is in a range from about 1:1 to about 1:3.

### Claim 12 (depends on 8)

The method of claim 8, wherein the alkaline nanosilica dispersion has a pH in a range from 9.5 to 10.5.

### Claim 13

A method of controlling lost circulation in a lost circulation zone in a wellbore, comprising:
introducing a lost circulation material consisting essentially of an alkaline nanosilica dispersion and a sodium bicarbonate activator into the wellbore such that they contact the lost circulation zone,
wherein the alkaline nanosilica dispersion comprises 30-50 wt % of alkaline silica nanoparticles,
wherein the sodium bicarbonate activator is present in an amount in a range of 19 wt % to 40 wt % of the lost circulation material, and
forming a gelled solid from the lost circulation material in the lost circulation zone.

### Claim 14 (depends on 13)

The method of claim 13, wherein the alkaline nanosilica dispersion comprises alkaline silica nanoparticles having a size in the range from about 10 nm to about 70 nm.

### Claim 15 (depends on 13)

The method of claim 13, wherein a weight ratio of the sodium bicarbonate activator to the alkaline silica nanoparticles is in a range from about 1:1 to about 1:3.

### Claim 16 (depends on 13)

The method of claim 13, wherein the alkaline nanosilica dispersion has a pH in a range from 9.5 to 10.5.