# US 6,719,053 B2 · Ester/monoester copolymer compositions and methods of preparing and using same

> Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt

- Number: US 6,719,053 B2
- Document ID: US6719053B2
- Status: Granted
- Kind: B2
- Application number: 10/134,745
- Filed: 2002-04-29
- Published: 2003-03-06
- Granted: 2004-04-13
- Earliest claimed: 2001-04-30
- Assignees: BJ Services Company
- Inventors: Joseph E. Thompson
- Web page: https://patentgrep.com/patent/US6719053B2

## CPC

- C08K 5/00: Use of organic ingredients
- C09K 8/12: containing synthetic organic macromolecular compounds or their precursors
- C09K 8/32: Non-aqueous well-drilling compositions, e.g. oil-based
- C09K 8/64: Oil-based compositions
- C09K 8/685: {containing cross-linking agents}
- C09K 8/82: Oil-based compositions (C09K8/64 takes precedence)
- C09K 8/882: {obtained by reactions only involving carbon-to-carbon unsaturated bonds}
- C08K: Use of inorganic or non-macromolecular organic substances as compounding ingredients (paints, inks, varnishes, dyes, polishes, adhesives C09)
- C09K: MATERIALS FOR MISCELLANEOUS APPLICATIONS, NOT PROVIDED FOR ELSEWHERE

## Abstract

Compositions comprising a base fluid and a monoester copolymer of styrene and maleic anhydride are disclosed. The compositions can further comprise an alkyl orthophosphate ester. The base fluid can be an aqueous or organic base fluid. The monoester copolymer is at least partially soluble or dispersible in the base fluid. Preferably, the composition may further include a cross-linking agent capable of increasing the viscosity of the composition, such as aluminum isopropoxide or other metal source compounds. The composition can form a gel which is stable at a temperature of about 250° F. (121° C.) or higher. Some gels of the present invention exhibit stability up to about 300° F. (149° C.) to 350° F. (177° C.) or higher. The compositions have many applications, such as pipeline treatment, conformance, hydraulic fracturing, well completion, gravel packing, drilling fluids, process facility treatment fluids, and other well treatment applications.

## Claims

### Claim 1

A method of treating a subterranean formation, the method comprising:
providing a mixture comprising an organic base fluid, a monoester copolymer of styrene and maleic anhydride, and an alkyl orthophosphate ester; and
injecting the mixture into at least a portion of the subterranean formation.

### Claim 2 (depends on 1)

The method of claim 1, wherein the monoester copolymer is at least partially soluble or dispersible in the organic base fluid.

### Claim 3 (depends on 1)

The method of claim 1, further comprising adding a crosslinking agent to the mixture to form a gel, wherein the crosslinking agent is capable of increasing the viscosity of the mixture.

### Claim 4 (depends on 3)

The method of claim 3, wherein the crosslinking agent is added before the mixture is injected into the subterranean formation.

### Claim 5 (depends on 3)

The method of claim 3, wherein the crosslinking agent is added after the mixture is injected into the subterranean formation.

### Claim 6 (depends on 3)

The method of claim 3, wherein the crosslinking agent is added concurrently as the mixture is injected into the subterranean formation.

### Claim 7 (depends on 3)

The method of claim 3, wherein a breaking agent is added to the gel to decrease its viscosity.