High Temperature Crosslinked Fracturing Fluids

• US 20190016946A1
• Filed: 09/18/2018
• Published: 01/17/2019
• Est. Priority Date: 12/02/2015
• Status: Active Grant

• Current Assignee: Saudi Arabian Oil Company (Government of Saudi Arabia)
• Original Assignee: Saudi Arabian Oil Company (Government of Saudi Arabia)
• Inventors: Liang, Feng, Reddy, B. Raghava, Li, Leiming, Al-Muntasheri, Ghaithan A.
• Granted Patent: US 10,640,700 B2
• Time in Patent Office: Days
• CPC Class Codes: C08F 220/06 Acrylic acid; Methacrylic acid; Metal salts or ammonium salts thereof
• CPC Class Codes: C08F 220/56 Acrylamide; Methacrylamide
• CPC Class Codes: C08F 220/585 and containing other heteroatoms, e.g. 2-acrylamido-2-methylpropane sulfonic acid [AMPS]
• CPC Class Codes: C09K 2208/12 Swell inhibition, i.e. using additives to drilling or well treatment fluids for inhibiting clay or shale swelling or disintegrating
• CPC Class Codes: C09K 2208/24 Bacteria or enzyme containing gel breakers
• CPC Class Codes: C09K 2208/26 Gel breakers other than bacteria or enzymes
• CPC Class Codes: C09K 8/685 containing cross-linking agents
• CPC Class Codes: C09K 8/725 Compositions containing polymers
• CPC Class Codes: C09K 8/74 combined with additives added for specific purposes
• CPC Class Codes: C09K 8/887 containing cross-linking agents
• CPC Class Codes: E21B 43/26 by forming crevices or fractures

Abstract

A fracturing fluid including a mixture of an aqueous copolymer composition including a copolymer, the copolymer having 2-acrylamido-2-methylpropanesulfonic acid, acrylamide, and acrylic acid monomer units, or a salt thereof, and a crosslinker. The crosslinker includes a metal, and the weight ratio of the metal to the copolymer is in a range of 0.01 to 0.08. Treating a subterranean formation includes introducing the fracturing fluid into a subterranean formation, and crosslinking the fracturing fluid in the subterranean formation to yield a crosslinked fracturing fluid. The crosslinked fracturing fluid has a viscosity of at least 500 cP for at least 80 minutes when the gel is subjected to a shear rate of 40 s⁻¹ at a temperature in a range of 300° F. to 400° F.

Claims

1. A fracturing fluid comprising a mixture of:

an aqueous copolymer composition comprising a copolymer, the copolymer comprising 2-acrylamido-2-methylpropanesulfonic acid, acrylamide, and acrylic acid monomer units, or a salt thereof, wherein the copolymer comprises 1 mol % to 25 mol % of the 2-acrylamido-2-methylpropanesulfonic acid monomer units; and

a crosslinker comprising a metal,

wherein a weight ratio of the metal to the copolymer is in a range of 0.01 to 0.08 and

wherein the fracturing fluid comprises 20 to 50 pounds of the copolymer per thousand gallons of the fracturing fluid.

2. The fracturing fluid of claim 1, wherein the weight ratio of the metal to the copolymer is in a range of 0.02 to 0.06.

7. The fracturing fluid of claim 1, comprising at least one of a gel stabilizer, a clay stabilizer, a viscosity breaker, a proppant, and a pH adjusting agent.

8. The fracturing fluid of claim 7, comprising the pH adjusting agent, wherein a pH of the fracturing fluid is in a range of 2 to 7 or 3 to 6.5.

9. The fracturing fluid of claim 1, comprising between 50 mg/L and 50,000 mg/L of total dissolved solids.

10. The fracturing fluid of claim 1, wherein a concentration of the metal in the fracturing fluid is in a range of 0.001 wt % to 0.024 wt %.

12. The fracturing fluid of claim 1, wherein, after crosslinking, the fracturing fluid has a viscosity of at least 500 cP for at least 80 minutes when the gel is subjected to a shear rate of 40 s⁻

1 at a temperature in a range of 300°

F. to 400°

F.

3-6. -6. (canceled)

11. (canceled)

13. A fracturing fluid comprising a mixture of:

an aqueous copolymer composition comprising a copolymer, the copolymer comprising 2-acrylamido-2-methylpropanesulfonic acid, acrylamide, and acrylic acid monomer units, or a salt thereof, and wherein the copolymer comprises 1 mol % to 25 mol % of the 2-acrylamido-2-methylpropanesulfonic acid monomer units; and

a crosslinker comprising a metal,

wherein a weight ratio of the metal to the copolymer is in a range of 0.01 to 0.08, and the crosslinker is present in an amount sufficient to yield a crosslinked fluid having a viscosity of at least 500 cP at 300 °

F. at a pH less than 7.

14. The fracturing fluid of claim 13, wherein the crosslinker comprises a water-miscible, non-aqueous fluid.

17. The fracturing fluid of claim 13, wherein the weight ratio of the metal to the copolymer is in a range of 0.02 to 0.06.

18. The fracturing fluid of claim 13, wherein a concentration of the metal in the fracturing fluid is in a range of 0.001 wt % to 0.024 wt %.

19. The fracturing fluid of claim 13, wherein the fracturing fluid comprises 20 to 50 pounds of the copolymer per thousand gallons of the fracturing fluid.

21. The fracturing fluid of claim 13, wherein a pH of the fracturing fluid is in a range of 5 to 7.

15-16. -16. (canceled)

20. (canceled)