Provided herein are compositions, methods, and systems related to cement blend composition comprising reactive vaterite cement and supplementary cementitious material (SCM) comprising aluminosilicate material.

The invention concerns a method for fluidifying wet concrete or industrial mortar compositions comprising: (a) at least one hydraulic binder, (b) at least one water reducing polymer, (c) at least one accelerator in the form of a salt containing at least one kosmotropic ion, (d) water, and (e) possibly one or more supplementary cementitious materials, and (f) possibly one or more filler materials, the method comprising a step of adding at least one salt (ch) including at least one chaotropic ion to the concrete or industrial mortar composition.

The invention concerns a method for fluidifying wet concrete or industrial mortar compositions comprising: (a) at least one hydraulic binder, (b) at least one water reducing polymer, (c) at least one accelerator in the form of a salt containing at least one kosmotropic ion, (d) water, and (e) possibly one or more supplementary cementitious materials, and (f) possibly one or more filler materials, the method comprising a step of adding at least one salt (ch) including at least one chaotropic ion to the concrete or industrial mortar composition.

A method for the continuous production of a mineral foam of which the density in the dry state (d) is from 40 to 600 kg/m.sup.3, includes (i) mixing cement; a water reducing agent; 0.5 to 10%, % by weight with respect to the total weight of cement, of ultrafine particles having a liquid-solid contact angle comprised from 30° to 140°, and of which the D50 is from 10 to 600 nm; water, with a water/cement weight ratio from 0.3 to 2.5; (ii) adding to the mixture from 0.5 to 10% of a pore-forming agent, % by weight with respect to the weight of cement; (iii) applying the mixture obtained at step (ii) on a support; (iv) leaving the mixture to expand on the support.

A method for the continuous production of a mineral foam of which the density in the dry state (d) is from 40 to 600 kg/m.sup.3, includes (i) mixing cement; a water reducing agent; 0.5 to 10%, % by weight with respect to the total weight of cement, of ultrafine particles having a liquid-solid contact angle comprised from 30° to 140°, and of which the D50 is from 10 to 600 nm; water, with a water/cement weight ratio from 0.3 to 2.5; (ii) adding to the mixture from 0.5 to 10% of a pore-forming agent, % by weight with respect to the weight of cement; (iii) applying the mixture obtained at step (ii) on a support; (iv) leaving the mixture to expand on the support.

Remediation of a hydrocarbon producing well bore in a subterranean formation includes injecting fluid containing self-degrading particulates into the well bore in order to stop production of hydrocarbon from the well bore prior to commencement of remedial operations and to temporarily seal the well bore from fluid transmission between the well bore and the formation prior to commencement of the remedial operations, and commencing the remedial operations upon the well bore. Examples of the remedial operations include injecting weighted fluid into the well bore, inserting a down-hole tool into the well bore, casing treatment, annulus treatment, well bore wall treatment, cementing, and refracturing. For refracturing, the fluid containing the self-degrading particulates can be injected until a down-hole pressure exceeds a fracture breakdown pressure of new fractures that will be produced by a perforating tool lowered into the well bore.

Remediation of a hydrocarbon producing well bore in a subterranean formation includes injecting fluid containing self-degrading particulates into the well bore in order to stop production of hydrocarbon from the well bore prior to commencement of remedial operations and to temporarily seal the well bore from fluid transmission between the well bore and the formation prior to commencement of the remedial operations, and commencing the remedial operations upon the well bore. Examples of the remedial operations include injecting weighted fluid into the well bore, inserting a down-hole tool into the well bore, casing treatment, annulus treatment, well bore wall treatment, cementing, and refracturing. For refracturing, the fluid containing the self-degrading particulates can be injected until a down-hole pressure exceeds a fracture breakdown pressure of new fractures that will be produced by a perforating tool lowered into the well bore.

The present invention provides calcium sulphate-based product having reduced shrinkage after exposure to high temperatures, the product comprising gypsum, a pozzolan source (e.g. in an amount between 4-27 wt %) and a metal salt additive (in an amount between 0.5 and 10 wt %). The pozzolan source may be selected from a kaolinitic clay material, fly ash, rice husk ash, diatomaceous earths, volcanic ashes and pumices, micro-silica, silica fume and silicone oil. The metal salt additive may be a metal salt which decomposes between a temperature of 300-500° C. to yield a metal oxide, e.g. magnesium nitrate.

The present invention provides calcium sulphate-based product having reduced shrinkage after exposure to high temperatures, the product comprising gypsum, a pozzolan source (e.g. in an amount between 4-27 wt %) and a metal salt additive (in an amount between 0.5 and 10 wt %). The pozzolan source may be selected from a kaolinitic clay material, fly ash, rice husk ash, diatomaceous earths, volcanic ashes and pumices, micro-silica, silica fume and silicone oil. The metal salt additive may be a metal salt which decomposes between a temperature of 300-500° C. to yield a metal oxide, e.g. magnesium nitrate.

The present invention provides calcium sulphate-based product having reduced shrinkage after exposure to high temperatures, the product comprising gypsum, a pozzolan source (e.g. in an amount between 4-27 wt %) and a metal salt additive (in an amount between 0.5 and 10 wt %). The pozzolan source may be selected from a kaolinitic clay material, fly ash, rice husk ash, diatomaceous earths, volcanic ashes and pumices, micro-silica, silica fume and silicone oil. The metal salt additive may be a metal salt which decomposes between a temperature of 300-500° C. to yield a metal oxide, e.g. magnesium nitrate.