Methods and compositions for treating a subterranean formation with salt-tolerant cement slurries including treating a salt-containing subterranean formation having sodium salts, potassium salts, magnesium salts, calcium salts, or any combination thereof comprising: providing a salt-tolerant cement slurry comprising: a base fluid, a cementitious material, a pozzolanic material, a salt-tolerant fluid loss additive, a salt additive, and optionally, an elastomer, a weight additive, a fluid loss intensifier, a strengthening agent, a dispersant, or any combination thereof; introducing the salt-tolerant cement slurry into the subterranean formation; and allowing the salt-tolerant cement slurry to set.

The invention comprises a concrete form. The form comprises a first concrete forming panel having a first primary surface adapted for forming and contacting plastic concrete and a second primary surface opposite the first primary surface; a layer of insulating material contacting and substantially covering the second primary surface of the first concrete forming panel; and an insulating blanket adjacent the first concrete forming panel. A method of using the concrete form is also disclosed.

The invention comprises a concrete form. The form comprises a first concrete forming panel having a first primary surface adapted for forming and contacting plastic concrete and a second primary surface opposite the first primary surface; a layer of insulating material contacting and substantially covering the second primary surface of the first concrete forming panel; and an insulating blanket adjacent the first concrete forming panel. A method of using the concrete form is also disclosed.

The present invention relates to a low-activation concrete comprising high-purity limestone aggregate and white cement, or high-purity limestone aggregate and aluminous cement. The low-activation concrete reduces the content of Europium, Cobalt and Cesium, as well as the content of elements such as Aluminium, Sodium, and Magnesium, when compared to standard concrete compositions and compositions for low-activation concrete already known in the art. The use of the low-activation concrete for forming an interior wall of a particle accelerator vault is provided as well.

The present invention relates to a low-activation concrete comprising high-purity limestone aggregate and white cement, or high-purity limestone aggregate and aluminous cement. The low-activation concrete reduces the content of Europium, Cobalt and Cesium, as well as the content of elements such as Aluminium, Sodium, and Magnesium, when compared to standard concrete compositions and compositions for low-activation concrete already known in the art. The use of the low-activation concrete for forming an interior wall of a particle accelerator vault is provided as well.

Cementing compositions containing a hydraulic cement, halloysite nanoparticles, and silica flour. The cementing compositions may optionally include other additives such as a friction reducer, a defoamer, and a fluid loss additive. Cement samples made therefrom and methods of producing such cement samples are also specified. The addition of halloysite nanoparticles and silica flour provides enhanced mechanical strength (e.g. compressive strength, flexural strength) and improved durability (e.g. resistance to CO.sub.2 and salinity) to the cement, making them suitable cementing material for oil and gas wells.

Cementing compositions containing a hydraulic cement, halloysite nanoparticles, and silica flour. The cementing compositions may optionally include other additives such as a friction reducer, a defoamer, and a fluid loss additive. Cement samples made therefrom and methods of producing such cement samples are also specified. The addition of halloysite nanoparticles and silica flour provides enhanced mechanical strength (e.g. compressive strength, flexural strength) and improved durability (e.g. resistance to CO.sub.2 and salinity) to the cement, making them suitable cementing material for oil and gas wells.

A hydraulic composition includes in relative parts by mass with respect to first Portland cement: 100 parts of a first Portland cement the particles of which have a D50 between 10 and 25 μm; from 25 to 76 parts of a second Portland cement the particles of which have a D50 between 0.5 and 6 μm; from 85 to 200 parts of sand; water; the water content being such that the hydraulic composition includes from 170 to 250 kg of water per cubic metre of hydraulic composition; the volume distribution of particle size of the first Portland cement and of the second Portland cement being further such that the ratio D50 of the first Portland cement/D50 of the second Portland cement is greater than 2.

A hydraulic composition includes in relative parts by mass with respect to first Portland cement: 100 parts of a first Portland cement the particles of which have a D50 between 10 and 25 μm; from 25 to 76 parts of a second Portland cement the particles of which have a D50 between 0.5 and 6 μm; from 85 to 200 parts of sand; water; the water content being such that the hydraulic composition includes from 170 to 250 kg of water per cubic metre of hydraulic composition; the volume distribution of particle size of the first Portland cement and of the second Portland cement being further such that the ratio D50 of the first Portland cement/D50 of the second Portland cement is greater than 2.

A hydraulic composition includes in relative parts by mass with respect to first Portland cement: 100 parts of a first Portland cement the particles of which have a D50 between 10 and 25 μm; from 25 to 76 parts of a second Portland cement the particles of which have a D50 between 0.5 and 6 μm; from 85 to 200 parts of sand; water; the water content being such that the hydraulic composition includes from 170 to 250 kg of water per cubic metre of hydraulic composition; the volume distribution of particle size of the first Portland cement and of the second Portland cement being further such that the ratio D50 of the first Portland cement/D50 of the second Portland cement is greater than 2.