Methods, compositions, and tools for use in creating rapidly forming plugs in situ in subterranean formations. In one instance, the disclosure provides a method that includes: placing a first pill comprising a calcium-aluminate-based cement composition at a plug location within the wellbore with the tubing; and placing a second pill comprising an alkaline fluid composition into the wellbore adjacent to the first pill with the tubing. In some cases there is a spacer fluid or spacer device between the first pill and the second pill. In some cases tubing having a mixing device is located at the bottom of the tubing in the wellbore to aid I mixing the first pill and the second pill to facilitate a chemical in situ reaction of the first pill and the second pill. The reaction between the first pill and the second pill forms a set plug at the plug location.

Methods, compositions, and tools for use in creating rapidly forming plugs in situ in subterranean formations. In one instance, the disclosure provides a method that includes: placing a first pill comprising a calcium-aluminate-based cement composition at a plug location within the wellbore with the tubing; and placing a second pill comprising an alkaline fluid composition into the wellbore adjacent to the first pill with the tubing. In some cases there is a spacer fluid or spacer device between the first pill and the second pill. In some cases tubing having a mixing device is located at the bottom of the tubing in the wellbore to aid I mixing the first pill and the second pill to facilitate a chemical in situ reaction of the first pill and the second pill. The reaction between the first pill and the second pill forms a set plug at the plug location.

A cementitious blend composition and a concrete mix composition preferable for making concrete resistant to high temperatures and alkaline conditions, particularly for making durable concrete for constructing an alumina digester tank in an aluminum smelter. The cementitious blend composition includes at least one hydraulic cement, silica fume (SF), and natural pozzolan (NP), wherein a weight percent ratio of at least one hydraulic cement:SF:NP in the cementitious blend composition lies in the range of (24-63):(5-44):(32-40) with the sum of the weight percentages of the at least one hydraulic cement, the SF, and the NP not exceeding 100%. The concrete mix composition comprises water and the cementitious blend composition, wherein a weight ratio of the water to the cementitious blend composition is 0.2-0.5, and wherein the concrete mix composition has a content of the cementitious blend composition of 400-550 kg/m.sup.3.

A cementitious blend composition and a concrete mix composition preferable for making concrete resistant to high temperatures and alkaline conditions, particularly for making durable concrete for constructing an alumina digester tank in an aluminum smelter. The cementitious blend composition includes at least one hydraulic cement, silica fume (SF), and natural pozzolan (NP), wherein a weight percent ratio of at least one hydraulic cement:SF:NP in the cementitious blend composition lies in the range of (24-63):(5-44):(32-40) with the sum of the weight percentages of the at least one hydraulic cement, the SF, and the NP not exceeding 100%. The concrete mix composition comprises water and the cementitious blend composition, wherein a weight ratio of the water to the cementitious blend composition is 0.2-0.5, and wherein the concrete mix composition has a content of the cementitious blend composition of 400-550 kg/m.sup.3.

A mortar composition, in particular for preparing a viscoelastic structure and/or a fire barrier, including: a) 15-50 wt.-% of a hydraulic binder, b) 5-35 wt.-% of lightweight aggregates, c) 5-25 wt. % of further aggregates which have a particle density that is higher than the particle density of the lightweight aggregates, and d) 10-50 wt.-% of a polymer.

A mortar composition, in particular for preparing a viscoelastic structure and/or a fire barrier, including: a) 15-50 wt.-% of a hydraulic binder, b) 5-35 wt.-% of lightweight aggregates, c) 5-25 wt. % of further aggregates which have a particle density that is higher than the particle density of the lightweight aggregates, and d) 10-50 wt.-% of a polymer.

The invention relates to a process for producing a composite comprising: a. providing a particulate material, wherein the particulate material comprises minerals having a content of at least 30% m/m of calcium, magnesium, aluminium, silicon, potassium or iron, or a combination of two or more thereof. b. providing an aggregate, c. providing a primary additive, wherein the primary additive comprises a sugar or derivative thereof, a polyol or derivative thereof, an organic acid, an organic acid salt or an inorganic acid, or any combination of two or more thereof, d. mixing the particulate material, the aggregate and the primary additive with water to form a mixture, and e. carbonating the mixture in the presence of carbon dioxide, wherein the concentration of carbon dioxide is greater than about 2 vol %.

The invention relates to a process for producing a composite comprising: a. providing a particulate material, wherein the particulate material comprises minerals having a content of at least 30% m/m of calcium, magnesium, aluminium, silicon, potassium or iron, or a combination of two or more thereof. b. providing an aggregate, c. providing a primary additive, wherein the primary additive comprises a sugar or derivative thereof, a polyol or derivative thereof, an organic acid, an organic acid salt or an inorganic acid, or any combination of two or more thereof, d. mixing the particulate material, the aggregate and the primary additive with water to form a mixture, and e. carbonating the mixture in the presence of carbon dioxide, wherein the concentration of carbon dioxide is greater than about 2 vol %.

Disclosed is a sulfate corrosion-resistant concrete, a method for optimizing proportion and application thereof. The concrete is formed by mixing and stirring base stocks, aggregates, admixtures, external additives and water. The base stock of the concrete is 17.4-17.5 parts of Portland cement; the aggregates include 38.9 parts of basalt with aggregate size of 5-10 mm and 33.1-33.2 parts of basalt medium sand; the admixtures are 1.9-1.95 parts of silica fume or fly ash, and further including 0.23-0.24 part of polycarboxylate water reducer and 1.34-1.35 part of sulfate corrosion-resistant liquid preservative. Optimized proportion method: according to the corrosion characteristics of sulfate and corrosion environment parameters, determine the composition and proportion of basic samples and comparison samples, make and cure sample components, test the deep components of the samples, and obtain the optimal composition and proportion according to the test results.

A method of cementing may include: mixing at least a cement dry blend, water, and a liquid activated pozzolan additive to form a cement slurry, wherein the liquid activate pozzolan additive comprises a carrier fluid and an activated pozzolan; introducing the cement slurry into a wellbore penetrating a subterranean formation; and allowing the cement slurry to set.