Patent attributes
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.