# US 11,993,750 B2 · Coated nanosand as relative permeability modifier

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- Number: US 11,993,750 B2
- Document ID: US11993750B2
- Status: Granted
- Kind: B2
- Application number: 18/330,033
- Filed: 2023-06-06
- Published: 2023-10-05
- Granted: 2024-05-28
- Earliest claimed: 2021-02-18
- Assignees: Saudi Arabian Oil Company
- Applicants: Saudi Arabian Oil Company
- Inventors: Ayman Almohsin; Edreese Alsharaeh; Mohan Raj Krishnan; Mohieddin Alghazali
- Web page: https://patentgrep.com/patent/US11993750B2

## CPC

- C09K 8/504: Compositions based on water or polar solvents (C09K8/502 takes precedence)
- C09K 8/92: characterised by their form or by the form of their components, e.g. encapsulated material (C09K8/70 takes precedence)
- C09D 133/26: Homopolymers or copolymers of acrylamide or methacrylamide
- C09K 8/032: {Inorganic additives}
- C09K 8/5045: {containing inorganic compounds}
- C09K 8/512: containing cross-linking agents
- C09K 8/516: characterised by their form or by the form of their components, e.g. encapsulated material
- B82Y 40/00: Manufacture or treatment of nanostructures
- C09K 2208/10: Nanoparticle-containing well treatment fluids
- C09K: MATERIALS FOR MISCELLANEOUS APPLICATIONS, NOT PROVIDED FOR ELSEWHERE
- C09D: COATING COMPOSITIONS, e.g. PAINTS, VARNISHES OR LACQUERS; FILLING PASTES; CHEMICAL PAINT OR INK REMOVERS; INKS; CORRECTING FLUIDS; WOODSTAINS; PASTES OR SOLIDS FOR COLOURING OR PRINTING; USE OF MATERIALS THEREFOR (cosmetics A61K; processes for applying liquids or other fluent materials to surfaces, in general, B05D; staining wood B27K5/02; glazes or vitreous enamels C03C; natural resins, French polish, drying-oils, driers, turpentine, per se, C09F; polishing compositions other than French polish, ski waxes C09G; adhesives or use of materials as adhesives C09J; materials for sealing or packing joints or covers C09K3/10; materials for stopping leaks C09K3/12; processes for the electrolytic or electrophoretic production of coatings C25D)
- B82Y: SPECIFIC USES OR APPLICATIONS OF NANOSTRUCTURES; MEASUREMENT OR ANALYSIS OF NANOSTRUCTURES; MANUFACTURE OR TREATMENT OF NANOSTRUCTURES

## Abstract

Polyacrylamide (PAM)-coated nanosand that may be a relative permeability modifier (RPM) and that is applied to treat a wellbore in a subterranean formation. The treatment may be for excess water production. The PAM-coated nanosand is PAM-hydrogel-coated nanosand. The PAM-coated nanosand os nanosand coated with PAM hydrogel. The PAM hydrogel includes crosslinked PAM in water. Application of the PAM-coated nanosand may reduce water production from the subterranean formation into the wellbore. The PAM hydrogel of the PAM-coated nanosand may expand in a water zone of the subterranean formation to restrict water flow into the wellbore. The PAM hydrogel of the PAM-coated nanosand may contract in an oil zone of the subterranean formation so not to significantly restrict crude oil flow into the wellbore.

## Claims

### Claim 1

A relative permeability modifier (RPM) that is polyacrylamide (PAM)-coated nanosand comprising nanosand coated with PAM hydrogel, wherein the PAM hydrogel comprises crosslinked PAM in water.

### Claim 2 (depends on 1)

The RPM of claim 1, wherein at least 90 weight percent (wt %) of the PAM-coated nanosand is the water, and wherein concentration of the crosslinked PAM in the PAM-coated nanosand is in a range of 1 wt % to 9 wt %.

### Claim 3 (depends on 1)

The RPM of claim 1, wherein the nanosand comprises a particle size less than 100 nanometers (nm).

### Claim 4 (depends on 1)

The RPM of claim 1, wherein a weight ratio of the crosslinked PAM to the nanosand in the PAM-coated nanosand is in a range of 0.1 to 1.

### Claim 5 (depends on 1)

The RPM of claim 1, wherein the PAM hydrogel is configured to expand in response to the RPM in a water zone of a subterranean formation, and wherein the PAM hydrogel is configured to contract in response to the RPM in an oil zone of the subterranean formation.

### Claim 6 (depends on 1)

The RPM of claim 1, wherein concentration of the crosslinked PAM in the PAM-coated nanosand is in a range of 2 wt % to 6 wt %.