Hydraulic fracturing composition, method for making and use of same
A hydraulic fracturing composition includes: a superabsorbent polymer in an expanded state; a plurality of proppant particles disposed in the superabsorbent polymer; a well treatment agent, and a fluid to expand the superabsorbent polymer into the expanded state. A process for treating a well with well treatment agent includes disposing a hydraulic fracturing composition comprising the well treatment agent in a well. The well treatment agent can be a scale inhibitor, tracer, pH buffering agent, or a combination thereof.
1. A process for disposing a plurality of proppant particles in a fracture, the process comprising:
disposing a hydraulic fracturing composition in a fracture in a downhole environment, the hydraulic fracturing composition comprising:
a superabsorbent polymer in an expanded state and configured to break in response to a breaking condition, such that a decomposed polymer is formed from the superabsorbent polymer, the superabsorbent polymer comprising particles having internal 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 but no intra-particle crosslinks and being present in a mass concentration from 5 ppt to 100 ppt, based on total volume of the composition, the superabsorbent polymer comprising a repeat unit derived from an acrylic acid, an acrylate, an acrylamide, a vinylpyrrolidone, a vinyl acetate, a 2-acrylamide-2-methylpropanesulfonic acid, a derivative thereof, or a combination thereof; and the superabsorbent polymer in the expanded state having a viscosity of about 1 centipoise to 300 centipoise as measured by Ofite M900 rheometer at a temperature of 180° F.,
a plurality of proppant particles disposed in a space between adjacent superabsorbent polymer particles prior to release of the plurality of proppant particles from the superabsorbent polymer particles in response to breaking the superabsorbent polymer,
a well treatment agent comprising a scale inhibitor, a tracer, a pH buffering agent, or a combination thereof, and
a fluid to expand the superabsorbent polymer into the expanded state; and
breaking the superabsorbent polymer with a breaker after closing of the fracture commences; and
releasing the plurality of proppant particles from the superabsorbent polymer to dispose the plurality of proppant particles in the fracture,
wherein the hydraulic fracturing composition is free of gelling agents except for the superabsorbent polymer.
2. The process of claim 1 , further comprising decreasing undesired effects caused by scale formation, salt formation, paraffin deposition, asphaltene deposition, foaming agent deposition, emulsification, gas hydrate formation, corrosion, foaming agents, oxygen scavengers, H 2 S scavengers, biocides, surfactants, or a combination thereof, compared to a composition without the well treatment agent.
3. The process of claim 2 , wherein
the hydraulic fracturing composition comprises the pH buffering agent and a slow-release acid, and
the process further comprises lowering the pH of the hydraulic fracturing composition past the buffering range of the buffering agent before the breaking of the superabsorbent polymer.
4. The process of claim 1 , wherein the hydraulic fracturing composition comprises about 0.01 to about 10 wt % of the pH buffering agent, based on the total weight of the hydraulic fracturing composition.
5. The process of claim 4 , wherein the pH buffering agent maintains the pH of the hydraulic fracturing composition at about 6 to about 9.
6. The process of claim 4 , wherein the pH buffering agent maintains the pH of the hydraulic fracturing composition at about 7 to about 8.
7. The process of claim 4 , wherein the pH buffering agent is alkali or alkaline earth salt of a carbonate, a citrate, a gluconate, a phosphate or a tartrate, an oxide of an alkaline earth metal, an organic polyelectrolyte, or a combination thereof.
8. The process of claim 1 , wherein the hydraulic fracturing composition comprises the pH buffering agent and further comprises a slow-release acid.
9. The process of claim 8 , wherein the slow-release acid comprises glyoxal, an encapsulated acid, a coated acid, or a combination thereof.
10. The process of claim 1 , wherein the breaker comprises a peroxide, a persulfate, a peracid, or a combination thereof.
11. The process of claim 10 , wherein the breaker is encapsulated in an encapsulating material to prevent the breaker from contacting the superabsorbent polymer, and the encapsulating material is configured to release the breaker.
12. The process of claim 10 , wherein
the plurality of proppant particles is present in a mass concentration from 0.1 lb/gal to 12 lb/gal, based on the total volume of the composition, and
the breaker is present in a mass concentration from greater than 0 ppt to 20 ppt, based on the total volume of the composition.
13. The process of claim 1 , wherein the superabsorbent polymer comprises the repeat unit derived from an acrylic acid and its salts.
14. The process of claim 13 , wherein the superabsorbent polymer comprises the internal crosslinks derived from polyethylene glycol diacrylate.
15. The process of claim 1 , wherein the breaker comprises a persulfate.
16. The process of claim 1 , wherein the superabsorbent polymer particles have a size of 10 microns to 1,000 microns.