A fracturing fluid including a base fluid including salt water, a polymer, a crosslinker, and a nanomaterial. The crosslinker may include a Zr crosslinker, a Ti crosslinker, an Al crosslinker, a borate crosslinker, or a combination thereof. The nanomaterial may include ZrO.sub.2 nanoparticles, TiO.sub.2 nanoparticles, CeO.sub.2 nanoparticles; Zr nanoparticles, Ti nanoparticles, Ce nanoparticles, metal-organic polyhedra including Zr, Ti, Ce, or a combination thereof; carbon nanotubes, carbon nanorods, nano graphene, nano graphene oxide; or any combination thereof. The viscosity and viscosity lifetime of fracturing fluids with both crosslinkers and nanomaterials are greater than the sum of the effects of crosslinkers and nanomaterials taken separately. Moreover, this synergistic effect offers significant, practical advantages, including the ability to use salt water rather than fresh water for fracturing fluids, the ability to reduce polymer loading to achieve a desired viscosity, and the ability to achieve better formation cleanup after the fracturing treatment.

Friction reducers, fracturing fluid compositions and methods for treating subterranean formations, wherein friction reducer is a reacted, grafted or blend of natural gum and polyacrylamide having a molecular weight between 300,000 and 30,000,000.

Methods, compositions, and systems that use hydrogels of graft polymers for diversion of acidic treatment fluids in subterranean formations. A method for acid diversion may comprise: applying a first acidizing treatment to a first treatment zone of a subterranean formation; introducing a hydrogel to the first treatment zone, wherein the hydrogel comprises a graft polymer that is crosslinked; and applying a second acidizing treatment to the subterranean formation, wherein the hydrogel diverts the second acidizing treatment to a second treatment zone.

Proppant particulates are commonly used in hydraulic fracturing operations to maintain one or more fractures in an opened state following the release of hydraulic pressure. In complex fracture networks, it can be difficult to deposit proppant particulates fully within the fractures. In addition, low crush strengths may result in problematic fines formation. Polyaromatic hydrocarbons, commonly encountered in various refinery process streams, may serve as an advantageous precursor to proppant particulates. Polyaromatic hydrocarbons may undergo crosslinking under acid-catalyzed conditions in an aqueous solvent in the presence of a surfactant to form substantially spherical particulates that may serve as effective proppant particulates during fracturing operations. In situ formation of the proppant particulates may take place in some cases.

The present invention provides a contraction agent for a water-absorbing resin that is used as a proppant in stratum hydraulic fracturing, the contraction agent containing: a metal ion-containing substance and a breaking agent for water-absorbing resins used in stratum hydraulic fracturing; and an iron ion-containing substance and/or ascorbic acid, and/or a persulfate. Also provided is a kit for use in stratum hydraulic fracturing, the kit provided with a swelling agent containing a water-absorbing resin, an iron ion-containing substance, and ascorbic acid, the kit being for stratum hydraulic fracturing, wherein the kit consists of A) a proppant containing a water-absorbing resin, and B) a contraction agent for the water-absorbing resin containing a metal ion-containing substance.

A method of fracturing a subterranean formation may comprise: pumping a fracturing fluid into the subterranean formation, through a wellbore, at or above a fracture gradient of the subterranean formation, wherein the fracturing fluid comprises halloysite nanotubes.

A composition for use as a pressure-tolerant dual-crosslinker gel in a fracturing fluid that comprises polymer, the polymer operable to increase the viscosity of a fluid; boron-containing crosslinker, the boron-containing crosslinker operable to crosslink the polymer; and a transition metal oxide additive, the transition metal oxide additive operable to crosslink the polymer.

A crosslinked polymer comprising reactants of a first repeating unit, a second repeating unit, and a crosslinker that react to form the crosslinked polymer, wherein the first repeating unit is a sulfonic acid-containing monomer present from 50% to 99% by weight of the reactants, wherein the second repeating unit is selected from the group consisting of an N-vinyl amide-containing monomer, a terminal double bond-containing monomer, and any combination thereof, and is present from 1% to 50% by weight of the reactants, and wherein the crosslinker comprises at least two olefinic bonds, and is present in the range of about 9% to about 25% by weight of the reactants.

Methods including introducing a treatment fluid into a subterranean formation having at least one fracture therein, the treatment fluid comprising an aqueous base fluid and brush photopolymerized coated proppant particulates (bPCPPs), and placing the bPCPPs into the at least one fracture to form a proppant pack therein. The bPCPPs comprise proppant modified with a coupling agent photopolymerized to a derivatized hydrophilic polymer, thereby resulting in a brush polymer structure of the derivatized hydrophilic polymer extending from the proppant.

Disclosed herein are compositions and methods for delaying crosslinking of aqueous crosslinkable polymers such as polysaccharides in injectable compositions for hydraulic fracturing and related applications. The compositions and methods provide delayed crosslinking at high temperatures and pressures, such as those encountered by hydraulic fracturing compositions injected into subterranean environments. Compositions include injectable solutions comprising a competing agent that is a reaction product of a dialdehyde having 2 to 4 carbon atoms with a non-polymeric cis-hydroxyl compound. Provided are methods of making and using delayed-crosslinking compositions comprising crosslinker compositions containing zirconium complexes and the competing agents.