Fracturing fluids and methods of treating hydrocarbon formations
View Patent ↗A method of fracturing a subterranean formation penetrated by a well comprises: forming a fracturing composition comprising a carrier fluid; and a superabsorbent polymer component comprising one or more of the following: a first composite of a proppant and a first superabsorbent polymer in an unhydrated form, the first superabsorbent polymer being at least partially embedded in a void area of the proppant; a coated superabsorbent polymer; a superabsorbent material having a three-dimensional network; or a second composite of a second superabsorbent polymer and a slow-release breaker; and pumping the hydraulic fracturing composition into the subterranean formation to create or enlarge a fracture.
1. A method of fracturing a subterranean formation penetrated by a well, the method comprising:
forming a fracturing composition comprising
a carrier fluid,
a proppant,
a superabsorbent polymer comprising a repeating unit derived from an acrylate, an acrylic acid or a salt thereof, an acrylamide, a vinylpyrrolidone, a vinyl ester, a vinyl alcohol, a 2-acrylamide-2-methylpropanesulfonic acid, a derivative thereof, or a combination thereof, the superabsorbent polymer having crosslinks derived from ethyleneglycol diacrylate, polyethyleneglycol diacrylate, trimethylopropane trimethacrylate, ethoxylated trimethylol triacrylate, ethoxylated pentaerythritol tetracrylate, or a combination comprising at least one of the foregoing,
a breaker effective to break the superabsorbent polymer at a temperature of greater than about 250° F. in the absence of any activators, the breaker comprising a bromate breaker,
an encapsulated activator comprising an activator encapsulated within an encapsulant, the activator comprising sorbic acid and being effective to activate the breaker so that the breaker or a derivative thereof breaks the superabsorbent at a temperature of less than about 200° F.;
pumping the hydraulic fracturing composition into the subterranean formation to create or enlarge a fracture;
allowing the activator to diffuse out of the encapsulant; and
breaking the superabsorbent polymer using the breaker,
wherein the fracturing composition is free of a crosslinking agent.
2. The method of claim 1 , wherein the subterranean formation has an environmental temperature of less than about 200° F.
3. The method of claim 1 , wherein the breaker is sodium bromate.
4. The method of claim 1 , wherein the fracturing composition comprises about 1 pound to about 10 pounds of the breaker per one thousand gallons of the fracturing composition.
5. The method of claim 1 , wherein the fracturing composition comprises about 1 pound to about 4 pounds of the encapsulated activator per one thousand gallons of the fracturing fluid.
6. The method of claim 1 , wherein the fracturing composition comprises a composite of the superabsorbent polymer and the proppant.
7. The method of claim 6 , wherein the superabsorbent polymer at least partially penetrates or impregnates the proppant.
8. The method of claim 6 , wherein the proppant has pores or empty spaces.
9. The method of claim 8 , wherein the superabsorbent polymer at least partially penetrates the empty spaces of the proppant thus locking the proppant to the superabsorbent polymer.
10. The method of claim 1 , wherein the hydraulic fracturing composition further comprises one or more of the following: a peroxide; a persulfate; a perphosphate; a perborate; a percarbonate; a persilicate; an oxyacid of a halogen; an oxyanion of halogen; a peracid; or a derivative thereof.
11. The method of claim 1 , wherein the hydraulic fracturing composition further comprises sodium persulfate; ammonium persulfate; or potassium persulfate.
12. The method of claim 1 , wherein the superabsorbent polymer comprises a polyacrylamide having crosslinks derived from polyethylene glycol diacrylate.
13. A method of fracturing a subterranean formation penetrated by a well, the method comprising:
forming a fracturing composition comprising
a carrier fluid, and
a composite of a porous proppant, and a superabsorbent polymer formed by treating the porous proppant with the superabsorbent polymer under vacuum or pressure,
the superabsorbent polymer comprising a repeating unit derived from an acrylate, an acrylic acid or a salt thereof, an acrylamide, a vinylpyrrolidone, a vinyl ester, a vinyl alcohol, a 2-acrylamide-2-methylpropanesulfonic acid, a derivative thereof, or a combination thereof, the superabsorbent polymer having crosslinks derived from ethyleneglycol diacrylate, polyethyleneglycol diacrylate, trimethylopropane trimethacrylate, ethoxylated trimethylol triacrylate, ethoxylated pentaerythritol tetracrylate, or a combination comprising at least one of the foregoing,
a breaker effective to break the superabsorbent polymer at a temperature greater than about 250° F. in the absence of any activators, the breaker comprising a bromate breaker,
an encapsulated activator comprising an activator encapsulated within an encapsulant, the activator comprising sorbic acid and being effective to activate the breaker so that the breaker or a derivative thereof breaks the superabsorbent at a temperature of less than about 200° F.;
pumping the hydraulic fracturing composition into the subterranean formation to create or enlarge a fracture;
allowing the activator to diffuse out of the encapsulant; and
breaking the superabsorbent polymer using the breaker,
wherein the fracturing composition is free of a crosslinking agent.