A cement slurry composition, containing hydraulic cement, water, and from 1 to less than 4% of an organically modified nanoclay. A method for cementing a high pressure high temperature well by pumping the cement composition of claim 1 between a casing and a formation of a well bore to fill a gap between the casing and the formation, and allowing the cement to harden.

Described herein are plugging materials with polysaccharides that can be used in wellbore operations. A plugging material can include hydraulic cement, amorphous silica, polysaccharides, a retarder, clay, and an aqueous base, where the material is injectable into a wellbore. The polysaccharides can be cross-linked with borate. The retarder can be at least one of an organo phosphoric acid, a modified sulfonated styrene-maleic anhydride polymer, lignosulfonate, or a polyacrylic acid.

Described herein are plugging materials with polysaccharides that can be used in wellbore operations. A plugging material can include hydraulic cement, amorphous silica, polysaccharides, a retarder, clay, and an aqueous base, where the material is injectable into a wellbore. The polysaccharides can be cross-linked with borate. The retarder can be at least one of an organo phosphoric acid, a modified sulfonated styrene-maleic anhydride polymer, lignosulfonate, or a polyacrylic acid.

At least one glycol compound is used as a grinding aid when grinding at least one solid substance, in particular an inorganic and/or mineral solid substance, in a rolling mill, wherein the at least one glycol compound has a structure according to formula I: (formula 1) and wherein a) R1, R2, R3 each independently of one another stand for H or an alkyl, alkoxy or alkanol group with 1-8 carbon atoms, in particular with 2-4 carbon atoms; and b) X stands for a substituted or unsubstituted alkylene group with 1-8 carbon atoms, in particular 1-4 carbon atoms.

At least one glycol compound is used as a grinding aid when grinding at least one solid substance, in particular an inorganic and/or mineral solid substance, in a rolling mill, wherein the at least one glycol compound has a structure according to formula I: (formula 1) and wherein a) R1, R2, R3 each independently of one another stand for H or an alkyl, alkoxy or alkanol group with 1-8 carbon atoms, in particular with 2-4 carbon atoms; and b) X stands for a substituted or unsubstituted alkylene group with 1-8 carbon atoms, in particular 1-4 carbon atoms.

Embodiments relate to cementing operations and, in certain embodiments, to passivated cement accelerators and methods of using passivated cement accelerators in subterranean formations. An embodiment may comprise a method of cementing comprising: providing a cement composition comprising cement, water, and a passivated cement accelerator; and allowing the cement composition to set.

Embodiments relate to cementing operations and, in certain embodiments, to passivated cement accelerators and methods of using passivated cement accelerators in subterranean formations. An embodiment may comprise a method of cementing comprising: providing a cement composition comprising cement, water, and a passivated cement accelerator; and allowing the cement composition to set.

This invention relates to an adaptable Geopolymer cement composition for application in oil and gas wells having a wide range of downhole temperatures. The base Geopolymer cement composition has an acceptable rheology of below 200 cP and can be tailored by the inclusion of various chemicals to control properties such as thickening time over a wide range of temperatures and densities. The disclosed Geopolymer cement composition is pumpable, mixable and stable. The composition can also be adapted to have expandable and swellable properties.

This invention relates to an adaptable Geopolymer cement composition for application in oil and gas wells having a wide range of downhole temperatures. The base Geopolymer cement composition has an acceptable rheology of below 200 cP and can be tailored by the inclusion of various chemicals to control properties such as thickening time over a wide range of temperatures and densities. The disclosed Geopolymer cement composition is pumpable, mixable and stable. The composition can also be adapted to have expandable and swellable properties.

A method for producing a supplementary cementitious material (SCM) that includes providing a starting material containing dolomite and aluminium silicate, converting the starting material to the supplementary cementitious material by burning in the temperature range of >800 to 1100° C. or by burning in the temperature range of 725 to 950° C. in the presence of a mineralizer and cooling the supplementary cementitious material.