Treatment fluids for acid stimulation operations and methods related thereto

Patent metadata

Field	Value
Publication number	US-12435263-B2
Application number	US-202418664761-A
Country	US
Kind code	B2
Filing date	May 15, 2024
Priority date	Nov 21, 2023
Publication date	Oct 7, 2025
Grant date	Oct 7, 2025

Abstract

Treatment fluids for acid stimulation operations and methods related thereto. Treatment fluids comprise: an aqueous acid solution comprising a mineral acid and an organic acid; and a retardation additive comprising: 1-15 wt % of an oleaginous liquid; 5-30 wt % of a fatty alkyl alcohol ethoxylate; 2-40 wt % of at least one of a fatty alkyl ethoxylated ammonium salt, a zwitterionic surfactant, an alkyl ether sulfate salt, or an alkyl ether sulfonate salt; 4-30 wt % of a co-solvent; and 10-85 wt % of an aqueous fluid, each wt % based on a total mass of the retardation additive. Treatment fluids or retardation additives may be oil-in-water emulsions. Treatment fluids may have 0.5-5 gallons per thousand, based on an overall volume of the treatment fluid of the retardation additive. Methods comprise providing and introducing the treatment fluid into a subterranean formation during a stimulation operation.

First claim

What is claimed is:

1. A treatment fluid comprising:
an aqueous acid solution comprising a mineral acid and an organic acid; and
a retardation additive, wherein the retardation additive comprises:
1 wt % to 15 wt % of an oleaginous liquid;
5 wt % to 30 wt % of a fatty alkyl alcohol ethoxylate;
2 wt % to 40 wt % of at least one of an alkyl ether sulfate salt;
4 wt % to 30 wt % of a co-solvent; and
10 wt % to 85 wt % of an aqueous fluid, each wt % based on a total mass of the retardation additive, and wherein the retardation additive has a volume concentration in the treatment fluid of 0.5 gallons per thousand (gpt) to 5 gpt, based on an overall volume of the treatment fluid, and,

wherein the treatment fluid forms an oil-in-water emulsion.

2. The treatment fluid of claim 1 , wherein the mineral acid comprises 10 wt % to 30 wt % hydrochloric acid solution, by total weight of the hydrochloric acid solution, wherein the organic acid comprises methane sulfonic acid, glutamic acid diacetate, or any combination thereof, and wherein the organic acid comprises an organic acid solution with an acid concentration of 10 wt % to 80 wt %, by total weight of the organic acid solution.

3. The treatment fluid of claim 1 , wherein the mineral acid comprises a mineral acid solution and the organic acid comprises an organic acid solution, and wherein the mineral acid solution and the organic acid solution are in a ratio of 9:1 to 1:1, by volume of the solutions.

4. The treatment fluid of claim 1 , wherein the oleaginous liquid comprises a terpene, a hydrocarbon, a fatty acid ester, or any combination thereof.

5. The treatment fluid of claim 1 , wherein the fatty alkyl alcohol ethoxylate comprises a linear or branched C 6 -C 18 alcohol ethoxylate comprising 3 to 30 ethoxylate repeat units.

6. The treatment fluid of claim 1 , wherein the fatty alkyl ethoxylated ammonium salt is present and comprises at least one functionalized alkyl group having 3 to 30 ethoxylate repeat units.

7. The treatment fluid of claim 1 , wherein the zwitterionic surfactant is present and comprises a C 12 -C 18 betaine, a C 12 -C 18 sultaine, or any combination thereof.

8. The treatment fluid of claim 1 , wherein the alkyl ether sulfate salt or the alkyl ether sulfonate salt is present and comprises an ammonium salt.

9. The treatment fluid of claim 1 , wherein the co-solvent comprises an alcohol, a glycol, a glycol ether, a glycol ester, or any combination thereof.

Assignees

• Saudi Arabian Oil Co

Inventors

• Saini Rajesh Kumar
• Sayed Mohammed
• Cairns Amy J

Classifications

• E21B43/26

  by forming crevices or fractures · CPC title

• E21B43/16

  Enhanced recovery methods for obtaining hydrocarbons · CPC title

• C09K8/602

  containing surfactants · CPC title

• C09K8/74 Primary

  combined with additives added for specific purposes · CPC title