This invention relates to an adaptable Geopolymer cement composition for application in oil and gas wells having a wide range of downhole temperatures. The base Geopolymer cement composition has an acceptable rheology of below 200 cP and can be tailored by the inclusion of various chemicals to control properties such as thickening time over a wide range of temperatures and densities. The disclosed Geopolymer cement composition is pumpable, mixable and stable. The composition can also be adapted to have expandable and swellable properties.

The present invention includes well treatment fluids and methods utilizing nano-particles and, in certain embodiments, to sealant compositions and methods utilizing nano-particles. The nano-particles may be incorporated into the sealant composition in different forms, including as discrete nano-particles, encapsulated nano-particles, agglomerated nano-particles, or in a liquid suspension.

The present invention relates to an inorganic binder system comprising blast furnace slag, and at least one solid alkali metal silicate, wherein the inorganic binder system is obtainable by co-grinding a mixture comprising the blast furnace slag and the at least one solid alkali metal silicate.

A concrete mix, including: cementitious content between 25 and 200 kg/m.sup.3; fly ash content between 25 and 175 kg/m.sup.3; dirty sand with fine aggregates between 3% and 20%; water content between 150 I/m.sup.3 and 250 l/m.sup.3; and a chemical admixture comprising one or more components selected from the following: an acrylic, formaldehyde-free polymer-based admixture, modified in aqueous solution; a surfactant admixture configured to entrain micro air bubbles in concrete; and an organic polymer comprising hydrophilic groups for increasing the viscosity of the mixture.

Expansive cement compositions for use in subterranean wellbores that include a monophase amorphous hydraulic binder material (MAHBM). The MAHBM may include a plurality of particles having a silica core and an amorphous coating substantially surrounding the silica core. The coating may comprise, for example, a plurality of amorphous α-dicalcium silicate hydrate nanoparticles or microparticles. The MAHBM may be used as an expansion agent in a cement composition or used as an expansive cement by itself.

A sulfate-resistant cement composition may contain calcium magnesium aluminum oxide silicate, brownmillerite, dolomite, periclase, and calcium aluminum oxide. The composition may contain the calcium aluminum oxide in an amount in the range of 0.01 to 2.0 wt. %. The composition may contain the brownmillerite in an amount of the range of 20 to 30 wt. %.

A method for reinforcing a structure comprising the following steps: preparation of UHPFRC comprising a cement precursor mix, of water, a fluidizing agent and metal fibers, transporting the UHPFRC by pumping to a suitable spray nozzle, spraying the mix onto a surface of the structure by the addition of a compressed air stream in the spray nozzle.

A 3D printable clay-based mortar cementitious ink includes a blend of commercially available Type I/II Portland cement, and a fine and coarse silica sand. The ratio of Portland cement to fine sand or fine clay, may be approximately 1.02. The ratio of water-to-binder (Portland cement and SCM) may be approximately 0.55, and the ratio of water-to-powder (binder plus fine clay smaller than 75 microns) can be approximately 0.416. Included with the water and binder/powder mix is an admixture. According to one embodiment, the admixture can include a water reducing admixture, or plasticizer. The fine clay within the aggregate material is unprocessed, and the binder material is approximately 84 to 90 percent cement and 10 to 16 percent SCM. The unprocessed clay, or fine sand, does not undergo any heating, any chemical modification or sifting before being added to the aggregate material.

A method for preparing an accelerator for sprayed mortar/concrete is provided. The accelerator includes an organic component, inorganic component aluminum sulfate, an initiator, and a reductant. The organic component in the form of a polymer monomer is added to concrete and polymerized into a polymer network structure in the presence of the initiator and the reductant; and the inorganic component aluminum sulfate promotes rapid hydration of the concrete to form an inorganic network structure. Such organic-inorganic interpenetrating network thickens a cement-based material rapidly to achieve strong adhesion, fast-setting and hardening properties and effectively reduces resilience of the sprayed mortar/concrete. The accelerator prepared by the method is well compatible with all sorts of cement, efficient and environmentally friendly. The organic-inorganic interpenetrating network is formed by polymerization and cement hydration, and therefore, the toughness of the sprayed mortar/concrete is improved by the organic polymer-inorganic compound accelerator.

Techniques of forming a foamed insulation material from gypsum waste are disclosed herein. One example technique includes mechanically comminuting the gypsum waste from an original size into particles of gypsum at a target size smaller than the original size and mixing the particles of the gypsum with a binder to form a mixture of particles and binder. The binder is configured to bind the particles of gypsum upon hydration. The example technique can further include performing air entrainment on the mixture until a foam is formed from the mixture having the particles of gypsum and binder. The foam has water that causes the binder to bind the particles of gypsum. The example technique can then include removing moisture from the mixture with the formed foam to form a foamed insulation material from the particles of gypsum.