A method of treating a subterranean formation penetrated by a well-bore, for example to facilitate fracturing of the formation, comprises the steps of: (i) selecting a treatment fluid comprising a diverting agent (A) in a flaked form, for example guar gum in a flaked form. (ii) introducing the treatment fluid into the subterranean formation via the well-bore to plug a region of the formation. Thereafter, the formation may be fractured or re-fractured.

Compositions and methods for fracturing a subterranean formation are presented. Also provided are compositions and methods for reducing friction-related losses in a well treatment fluid. In general, the compositions include a copolymer that includes one or more vinylphosphonic acid (“VPA”) monomers.

A nanoparticle-resin coated frac sand composition is provided. The nanoparticle-resin coated frac sand composition includes a silica sand, an epoxy resin, methanol, a hardener, and nanoparticles. The nanoparticles may be silica nanoparticles, alumina nanoparticles, zinc oxide (ZnO) nanoparticles, or titanium oxide (TiO.sub.2) nanoparticles. The methanol is used as a diluent for the epoxy resin. The nanoparticle-resin coated frac sand composition may be used as a proppant in a hydraulic fracturing operation, such by injecting a hydraulic fracturing fluid having the composition into a subterranean formation. Methods of manufacturing the composition and hydraulic fracturing of a subterranean formation are also provided.

A nanoparticle-resin coated frac sand composition is provided. The nanoparticle-resin coated frac sand composition includes a silica sand, an epoxy resin, methanol, a hardener, and nanoparticles. The nanoparticles may be silica nanoparticles, alumina nanoparticles, zinc oxide (ZnO) nanoparticles, or titanium oxide (TiO.sub.2) nanoparticles. The methanol is used as a diluent for the epoxy resin. The nanoparticle-resin coated frac sand composition may be used as a proppant in a hydraulic fracturing operation, such by injecting a hydraulic fracturing fluid having the composition into a subterranean formation. Methods of manufacturing the composition and hydraulic fracturing of a subterranean formation are also provided.

A fluid for use in hydraulic fracturing contains underivatized guar or a guar gum derivative as viscosifying or gelling polymer, a crosslinking agent, carbon dioxide as foaming agent and urea and, optionally, a bifunctional organic compound containing at least one hydroxyl group and at least one quaternary group and, optionally, a non-gaseous foaming agent. The fluid may be characterized by a low pH such as a pH than or equal to 3.0 and less than or equal to 5.0.

Chemical additives useful for hydraulic fracturing operation are comprising of lubricant/nonpolar solvents; hydro-dual-phobic domains as core encapsulated by emulsifiers as shell, suspended in water by hydrogel polymers as hydrophilic domains; soy protein isolate (SPI) and sweet rice flour were modified with crosslinking polymers of isocyanate as hydrophobic domains, which is incorporated into the frac fluid as a standard alone friction reducer solution or as an enhancer of frac fluid viscosity of the final frac fluid products in high salinity brines having a concentration as high as 25.0% at an ambient temperature at a downhole well temperature from 30 to 180° F.

The invention provides polymers comprising repeating units derived from at least one monomer comprising at least one functionalized or unfunctionalized acryloyl moiety and at least one lactam moiety; at least one monomer comprising at least one sulfonic acid moiety or a salt thereof; and at least one crosslinker. The invention further provides various compositions comprising the polymers. The invention furthermore provides applications of these compositions in various industrial arts, particularly in oilfield operations such as drilling and cementing.

Methods of treating a subterranean formation are disclosed that include placing a treatment fluid into a subterranean formation, the treatment fluid containing a one or more polymers capable of consolidating to form a polymeric structure at a downhole location. Also disclosed are treatment fluids including a polymeric structure for treating a subterranean formation.

A fracturing fluid including a mixture of an aqueous terpolymer composition including a terpolymer, an additive, and crosslinker. The terpolymer includes 2-acrylamido-2-methylpropanesulfonic acid, acrylamide, and acrylic acid monomer units, or a salt thereof. The additive includes a sugar alcohol or a derivative thereof, and the crosslinker includes a metal. The weight ratio of the metal to the terpolymer is in a range of 0.01 to 0.16, and a concentration of the additive is in a range of 0.001 wt. % to 10 wt. % of the fracturing fluid. 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 mitigates damage caused by substantial amounts of total dissolved solids or significant water hardness.

A method to reduce the viscosity of viscosified treatment fluids is disclosed herein. The method includes a water soluble polymer as viscosifying agent, preferably a synthetic water soluble polymer, optionally a crosslinker for the water soluble polymer, a breaker system containing an organic peroxide, mixing the viscosified treatment fluid and the breaker composition and allowing the viscosified treatment fluid and the breaker composition to interact whereby the viscosity of the viscosified treatment is reduced. The application of the process in the production of oil and gas is also discussed.