Fibers to be added to concrete to improve its properties are coated with an alkali-insoluble polymer, to provide adhesion of the fibers to the concrete. In a further improvement, nanoparticles are dispersed in an alkali-soluble polymer coating, and this is used to coat the fibers. When the fibers are mixed into the concrete mix, the nanoparticles are dispersed throughout the concrete, avoiding problems from agglomeration of the nanoparticles if simply added to the concrete mix.

Embodiments relate to the use of alkali aluminates and alkali silicates with cement kiln dust to form a settable composition for use in subterranean operations. An embodiment provides a method comprising: introducing a settable composition comprising cement kiln dust, an alkali aluminate, an alkali silicate, and an aqueous carrier fluid into a subterranean formation; and allowing the settable composition to set and thereby reduce fluid flow through a portion of the subterranean formation.

Embodiments relate to the use of alkali aluminates and alkali silicates with cement kiln dust to form a settable composition for use in subterranean operations. An embodiment provides a method comprising: introducing a settable composition comprising cement kiln dust, an alkali aluminate, an alkali silicate, and an aqueous carrier fluid into a subterranean formation; and allowing the settable composition to set and thereby reduce fluid flow through a portion of the subterranean formation.

A method of monitoring conditions in a wellbore by disposing capsules with a signaling agent downhole, and monitoring the presence of the signaling agent released from the capsules that escape the wellbore. The capsules are formed by combining immiscible liquids, where one of the liquids contains the signaling substance, and each of the liquids contains a reagent. When combined, the liquids segregate into a dispersed phase and a continuous phase, with the dispersed phase having the signaling agent. The reagents react at the interfaces between dispersed and continuous phases and form polymer layers encapsulating the signaling agent to form the capsules. When disposed downhole, such as in casing cement, the capsule membranes can burst under pressure or temperature to release the signaling agent. Adjusting relative concentrations of the reagents varies membrane strength and permeability.

A method of monitoring conditions in a wellbore by disposing capsules with a signaling agent downhole, and monitoring the presence of the signaling agent released from the capsules that escape the wellbore. The capsules are formed by combining immiscible liquids, where one of the liquids contains the signaling substance, and each of the liquids contains a reagent. When combined, the liquids segregate into a dispersed phase and a continuous phase, with the dispersed phase having the signaling agent. The reagents react at the interfaces between dispersed and continuous phases and form polymer layers encapsulating the signaling agent to form the capsules. When disposed downhole, such as in casing cement, the capsule membranes can burst under pressure or temperature to release the signaling agent. Adjusting relative concentrations of the reagents varies membrane strength and permeability.

The present invention concerns compositions and methods of using the same that provide encapsulated polymer nanocomposites for efficient crack repair and monitoring of a cement-substrate interface.

The invention relates to cementitious or grout compositions and drilling fluids including reinforcement fibers and methods relating thereto. The cementitious or grout compositions include dry blend material and reinforcement fibers. Each of the fibers can have one or more of a pre-selected mean length, denier, diameter and aspect ratio to improve dispersion in dry blending the cementitious or grout compositions.

The invention relates to cementitious or grout compositions and drilling fluids including reinforcement fibers and methods relating thereto. The cementitious or grout compositions include dry blend material and reinforcement fibers. Each of the fibers can have one or more of a pre-selected mean length, denier, diameter and aspect ratio to improve dispersion in dry blending the cementitious or grout compositions.

A sheet 100 of water-soluble material such as polyvinyl alcohol comprises a plurality of individual, sealed pockets 110, each pocket containing concrete admixture. The sheet is cut to size and attached to the interior of a formwork structure 200 with, for example, PVA glue. After concrete is poured into the formwork, covering the sheet 100, the sheet dissolves, releasing the admixture onto the surface of the concrete as it sets. In another arrangement, a sealed container 300 formed from a water-soluble material contains concrete admixture. The external wall of the container has a plurality of regions 320 where a thickness of the wall is reduced. The container is attached to interior walls of a formwork structure 200 or to reinforcing bars inside a formwork structure. After concrete is poured into the formwork, submerging the container, the container dissolves, with the thinner regions dissolving sooner, releasing the admixture into the concrete.

A sheet 100 of water-soluble material such as polyvinyl alcohol comprises a plurality of individual, sealed pockets 110, each pocket containing concrete admixture. The sheet is cut to size and attached to the interior of a formwork structure 200 with, for example, PVA glue. After concrete is poured into the formwork, covering the sheet 100, the sheet dissolves, releasing the admixture onto the surface of the concrete as it sets. In another arrangement, a sealed container 300 formed from a water-soluble material contains concrete admixture. The external wall of the container has a plurality of regions 320 where a thickness of the wall is reduced. The container is attached to interior walls of a formwork structure 200 or to reinforcing bars inside a formwork structure. After concrete is poured into the formwork, submerging the container, the container dissolves, with the thinner regions dissolving sooner, releasing the admixture into the concrete.