High temperature crosslinked fracturing fluids

• US 10,144,866 B2
• Filed: 12/01/2016
• Issued: 12/04/2018
• 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
• Primary Examiner(s): Bhushan, Kumar R
• Application Number:
  US15/366,928
• Publication Number:
  US 20170158951A1
• Time in Patent Office: 733 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 method of treating a subterranean formation, the method comprising:

introducing a fracturing fluid into a subterranean formation, the fracturing fluid comprising;

an aqueous copolymer composition comprising a copolymer, the copolymer comprising 2-acrylamido-2-methylpropane-sulfonic 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;

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

crosslinking the fracturing fluid in the subterranean formation to yield a crosslinked fracturing fluid wherein the crosslinked fracturing fluid comprises a viscosity breaker, and the crosslinked fracturing fluid maintains a viscosity of at least 500 cP for up to 180 minutes and has a viscosity of less than 10 cP after 360 minutes when the crosslinked fracturing fluid is subjected to a shear rate of 40 s<sup>−

1</sup> at a temperature of 300°

F.

2. The method 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 %.

3. The method of claim 1, wherein the crosslinker comprises zirconium, the fracturing fluid comprises 25 pounds of the copolymer per thousand gallons of the fracturing fluid, a weight ratio of the zirconium to the copolymer is in a range of about 0.02 to about 0.06, the copolymer comprises 15 mol % of the 2-acrylamido-2-methylpropane-sulfonic acid monomer units, and the crosslinked fracturing fluid maintains a viscosity of at least 500 cP for up to 180 minutes when the crosslinked fracturing fluid is subjected to a shear rate of 40 s⁻

1at a temperature of 300°

F.

4. The method of claim 1, wherein the crosslinker comprises zirconium, the fracturing fluid comprises 20 pounds of the copolymer per thousand gallons of the fracturing fluid, a weight ratio of the zirconium to the copolymer is in a range of about 0.02 to about 0.06, and the crosslinked fracturing fluid maintains a viscosity of at least 500 cP for up to 180 minutes when the crosslinked fracturing fluid is subjected to a shear rate of 40 s⁻

1 at a temperature of 300°

F.

5. The method of claim 1, wherein the crosslinker comprises zirconium, the fracturing fluid comprises 30 pounds of the copolymer per thousand gallons of the fracturing fluid, a weight ratio of the zirconium to the copolymer is in a range of about 0.02 to about 0.04, and the crosslinked fracturing fluid maintains a viscosity of at least 500 cP for up to 80 minutes when the crosslinked fracturing fluid is subjected to a shear rate of 40 s⁻

1 at a temperature of 400°

F.