A method of forming a barrier to overcome lost circulation in a subterranean formation. The method includes injecting a polymer-sand nanocomposite into one or more lost circulation zones in the subterranean formation where the polymer-sand nanocomposite is formed from sand mixed with a polymer hydrogel. Further, the polymer hydrogel includes a hydrogel polymer, an organic cross-linker, and a salt. The sand additionally comprises a surface modification. The associated method of preparing a polymer-sand nanocomposite lost circulation material for utilisation in forming the barrier is provided.

A tight oil reservoir CO.sub.2 flooding multi-scale channeling control system and a preparation method, including nanoscale CO.sub.2 responsive worm-like micellar systems and micron-scale CO.sub.2 responsive dispersion gel, are provided. The nanoscale CO.sub.2 responsive worm-like micelle system is prepared by CO.sub.2 reactive monomers and organic anti-ion monomers stirred in water. The micron-scale CO.sub.2 responsive dispersion gel is made of acrylamide, a responsive monomer, a silane coupling agent modified hydroxylated multi-walled carbon nanotubes as raw materials, cross-linked in water. The tight oil reservoir CO.sub.2 multi-scale channel control system, has strong flow control ability during CO.sub.2 displacement, and high-strength carbon nanotubes are introduced into the micro-scale CO.sub.2 responsive dispersion gel, which effectively improves the strength and long-term stability of the dispersion gel, significantly enhances the sealing effect on cracks, and after displacement of the CO.sub.2 of the system, the worm-like micelles revert to spherical micelles with good responsive reversibility.

The present disclosure discloses methods for preparing an in-situ nano emulsifier. The preparation method may include obtaining a solution by dissolving hydrated ferric chloride (or ferric chloride) and hydrated ferrous sulfate (or ferrous sulfate) into deionized water at a first temperature; obtaining an ethanol solution dissolved with an oil-soluble surfactant by dissolving an oil-soluble surfactant into ethanol at a second temperature; and adding a certain volume of ammonia water and the ethanol solution dissolved with the oil-soluble surfactant in the solution to obtain an in-situ nano emulsifier. The in-situ nano emulsifier may be applied to development of the oil reservoir through an application process. The application process may include preparing a nano emulsifier solution and a surfactant solution; sequentially injecting the surfactant solution and the nano emulsifier solution into a formation; and injecting a spacer liquid slug into the formation for replacement.

A method includes introducing into a drilling fluid a plurality of tags having a first clay nanoparticle and a first polymer embedded into the clay nanoparticle and circulating the drilling fluid and tags through a well during a drilling operation that creates formation cuttings such that the tags interact with the formation cuttings, creating tagged cuttings. The returned cuttings are collected from the circulating drilling fluid at a surface of the well, and the tags on the returned cuttings are detected to identify the tagged cuttings. The method also includes correlating the tagged cuttings with a drill depth in the well from the drilling operation.

According to embodiments disclosed herein, a gel fluid composite may include a nanosilica gel and a plurality of quantum dot tracers. The nanosilica gel may be configured to seal one or more downhole fractures in a wellbore. The plurality of quantum dot tracers may be dispersed in the nanosilica gel. The plurality of quantum dot tracers may each include a semiconductor particle core housed in a silica shell.

Method of making and using a proppant from captured carbon in either a carbon mineralization process or in a carbon nanomaterial manufacturing process, followed by treatments to ensure the quality control of the proppants so that they are suitable for use in hydraulic and other reservoir fracturing methods.

The present application discloses a nanometer self-locking bentonite film-forming agent, a method for preparing the same, and a film-forming drilling fluid.

The present disclosure relates to delivery and release systems, such as core-shell particles. An exemplary composition according to the disclosure can include a degradable polymeric shell surrounding a core that includes a crosslinker, which can encompass a metal, such as chromium. The core-shell particles can be provided with a gel-forming polymer, such as a polyacrylamide, into a subterranean reservoir having conditions such that the shell of the core-shell polymer degrades, and the so-released metal is effective to at least partially crosslink the gel-forming polymer to form a gel. The so-formed gel can be effective to control water flow through the subterranean reservoir, such as in relation to a waterflood of the reservoir.

Methods and compositions comprising nanoparticle additives for use in drilling and treatment fluid compositions are provided. In some embodiments the present disclosure includes providing a treatment fluid including an aqueous base fluid, a nanoparticle additive, and a viscosifier; introducing the treatment fluid into at least a portion of a subterranean formation to contact at least a portion of the subterranean formation; and allowing the treatment fluid to reduce fluid loss into the subterranean formation.

A composition, treatment fluid and method using hydrolyzable fines. A treatment fluid, which may optionally include a high solids content fluid (HSCF) and/or an Apollonianistic solids mixture, includes a fluid loss control agent comprising a dispersion of hydrolyzable fines, optionally with one or more of a surfactant, plasticizer, dispersant, degradable particles, reactive particles and/or submicron particles selected from silicates, γ-alumina, MgO, γ-Fe2O3, TiO2, and combinations thereof.