A concrete composition and method include a portion of fine aggregate bearing a coating of a polymer or an admixture, which may be a continuous coating layer or a layer of powdered, discrete particles embedded in a binder. The polymeric coating may be an admixture in powdered form, a super absorbent polymer (insoluble in water, but absorbing water), or another polymer such as the acrylamides, co-polymers thereof, polyacrylamides, or the like (soluble in water). The coating absorbs water, but particles are too small to form significant voids. Water is absorbed into the concrete mix in far greater proportions (e.g. w/c ratio over 0.5) improving workability, doubling workability time, and improving ultimate compressive stress (strength).

A method of producing a nanosilica-containing cement formulation, the method comprising the steps of mixing an amount of a determinant nanosilica particle and a functional coating; applying a dynamic initiator to trigger a reversible reaction of the functional coating to produce a reversible cage, where the reversible cage surrounds the determinant nanosilica particle to produce an encapsulated nanosilica; and mixing the encapsulated nanosilica and a cement formulation to produce the nanosilica-containing cement formulation

A method of producing a nanosilica-containing cement formulation, the method comprising the steps of mixing an amount of a determinant nanosilica particle and a functional coating; applying a dynamic initiator to trigger a reversible reaction of the functional coating to produce a reversible cage, where the reversible cage surrounds the determinant nanosilica particle to produce an encapsulated nanosilica; and mixing the encapsulated nanosilica and a cement formulation to produce the nanosilica-containing cement formulation

A concrete composition and method include a portion of fine aggregate bearing a coating of a polymer or an admixture, which may be a continuous coating layer or a layer of powdered, discrete particles embedded in a binder. The polymeric coating may be an admixture in powdered form, a super absorbent polymer (insoluble in water, but absorbing water), or another polymer such as the acrylamides, co-polymers thereof, polyacrylamides, or the like (soluble in water). The coating absorbs water, but particles are too small to form significant voids. Water is absorbed into the concrete mix in far greater proportions (e.g. w/c ratio over 0.5) improving workability, doubling workability time, and improving ultimate compressive stress (strength).

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.

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 enhancing carbonate precipitation in a downhole environment comprises introducing into the downhole environment a treatment composition comprising: a carbonate producing agent comprising a microbe, an enzyme, or a combination comprising at least one of the foregoing, and a substrate comprising N-oxyurea, semicarbazide, N,N-dioxyurea, or a combination comprising at least one of the foregoing. An organic feedstock and a geobacter can also be used to treating a wellbore or a subterranean formation. Encapsulated carbonate producing agent such as encapsulated bacterial spores are used to form self-healing cemented structure in a downhole environment.

A method of enhancing carbonate precipitation in a downhole environment comprises introducing into the downhole environment a treatment composition comprising: a carbonate producing agent comprising a microbe, an enzyme, or a combination comprising at least one of the foregoing, and a substrate comprising N-oxyurea, semicarbazide, N,N-dioxyurea, or a combination comprising at least one of the foregoing. An organic feedstock and a geobacter can also be used to treating a wellbore or a subterranean formation. Encapsulated carbonate producing agent such as encapsulated bacterial spores are used to form self-healing cemented structure in a downhole environment.