The composition for enhanced oil recovery includes metal oxide or carbonate nanoparticles capped or encapsulated by a water soluble poly(ionic liquid) (PIL). The nanoparticles may be, e.g., CaCO.sub.3, TiO.sub.2, Cu.sub.2O.Fe.sub.3O.sub.4, or ZrO.sub.2. The poly(ionic liquid) may be a copolymer of 2-acrylamido-2-methyl-1-propanesulfonic acid (AMPS) with N-isopropyl acrylamide, N-vinyl pyrrolidone, methacrylic acid, or acrylamide. The composition is made by synthesizing the metal oxide or carbonate nanoparticles in the presence of the PIL. The resulting nanocomposite or nanomaterial alters the wettability of carbonate rock in a carbonate reservoir, releasing asphaltenic crude oil from the surface of the carbonate rock and replacing oil in the pores of the rock, thereby enhancing secondary and tertiary oil recovery.

A method of pumping a fluid and reactive solid into a mineral formation includes the fluid reacting with the mineral formation to produce a nucleation product. The method may be used in shale formations to seal fissures and prevent leakage. The fluid used in this method may comprise CO.sub.2 and the nucleation products may be the products of carbonation reactions. A cement formed by reacting CO.sub.2 with a reactive solid under deep geological formation conditions is also disclosed.

A method of cementing may include preparing a cement composition comprising: cementitious components comprising: a cement; a supplementary cementitious material; and nanoparticulate boehmite; and water; and introducing the cement composition into a subterranean formation.

A method, wellbore, and pill for treating a region of a subterranean formation adjacent a wellbore zone of the wellbore, including injecting a gellable treatment composition (e.g., as the pill) through the wellbore zone into the region of the subterranean formation adjacent the wellbore zone, allowing the gellable treatment composition to form nanoparticles in-situ in the region and gel in the region via heat provided by the region to prevent or reduce flow of an unwanted fluid from the region into the wellbore zone. The gellable treatment composition may include a zwitterionic gemini surfactant (ZGS).

A method of breaking the viscosity of a treatment fluid comprises: adding hydrophobic nanoparticles to a treatment fluid comprising a base fluid and a viscoelastic surfactant gelling agent, the hydrophobic nanoparticles comprising metallic nanoparticles that are surface modified with C.sub.6-30 aliphatic groups, wherein the hydrophobic nanoparticles are added in an amount effective to decrease the viscosity of the treatment fluid as compared to a treatment fluid absent the hydrophobic nanoparticles.

A hydraulic fracture fluid is provided. The fluid can include a liquid solvent, one or more surfactants, a proppant-forming compound, and one or more curing agents. The liquid reacts to form proppant in-situ under downhole conditions.

Embodiments relate to use of graphite nanoplatelets (GnP) to enhance the mechanical and durability characteristics of cement that may be used as cement sheaths in wellbores of oil and gas wells. Generally, undesired permeability of cement is caused by diffusion of trapped oil and/or natural gas through the cementitious matrix of the cement, leading to material degradation of the cement. Methods disclosed involve using modified GnPs (having physically modified surfaces or chemically modified surfaces energies) to generate a cementitious nanocomposite with uniformly dispersed GnPs, which can effectively arrest the undesired diffusion mechanism. Modified GnPs can also increase the strength of interfacial adhesion (e.g., interfacial bonds and interfacial energies) between the GnP and the cement matrix (e.g., hydrations of the cement). Physical modification of GnP can involve non-covalent treatment techniques. Chemical modification of GnP can involve covalent treatment techniques.

Disclosed herein are graphene quantum dot tagged paraffin suppressants such as graphene tagged paraffin inhibitors and paraffin dispersants and methods of making and using thereof. The graphene quantum dots are covalently bound to residues of paraffin inhibitors or dispersed with paraffin dispersants to form tagged paraffin suppressants active in inhibiting paraffin crystallization or dispersing crystalized paraffin wax in crude oils and compositions comprising crude oils. The dots can be tailored to fluoresce at wavelengths with minimized correspondence to the natural fluorescence of crude oils, enabling the measurement of the concentration of the paraffin suppressants in crude oils or compositions comprising crude oils. The tagged suppressants are used to trace the dispersion and disposition of the paraffin suppressants in oils and compositions comprising them, for example within crude-oil recovery, production, processing, or conveyance and transportation, by in situ sampling the oil or composition and measuring the fluorescence of the sampled material.

Graphene quantum dots are functionalized by covalently bonding a corrosion inhibitor molecule thereto. In a useful method, a corrosion inhibitor compound is blended with a graphene quantum dot-tagged corrosion inhibitor compound, and the blend is applied to a metal surface, such as the interior of a carbon steel pipe. The blend inhibits corrosion arising from contact with produced water generated by hydrocarbon recovery from one or more subterranean reservoirs. The produced water having the blend dispersed therein is irradiated with a source of light having a selected first range of wavelengths, and the luminescent emission of the graphene quantum dot-tagged corrosion inhibitor is measured at a selected second range of wavelengths, thereby providing for real-time measurement of corrosion inhibitor concentration within the pipe.

Provided is a loss circulation material that may consist essentially of an acidic nanosilica dispersion and an activator. The acidic nanosilica dispersion may consist of acidic silica nanoparticles, stabilizer, and water, and may have a pH in a range of 3 to 6. The activator may be one or more from the group consisting of sodium bicarbonate, sodium chloride, or an amine salt. A method is provided for controlling lost circulation in a lost circulation zone in a wellbore comprising introducing the loss circulation material and forming a gelled solid from the loss circulation material in the lost circulation zone.