A method for subsurface sequestration of carbon in a subterranean zone includes forming a fluid-filled volume in the subterranean zone by injecting an aqueous into the subterranean zone and injecting a mixture comprising silicate nanoparticles suspended in an acidic solution having a pH of less than 4. Carbon in the form of carbon dioxide is injected into the fluid-filled volume such that a least a portion of the carbon is sequestered by precipitation of carbonate minerals. At least a portion of the carbonate minerals are formed from reaction of metal cations with bicarbonate formed from the carbon dioxide, and least a portion of the metal cations are a product of decomposition of the silicate nanoparticles in the acidic solution.

A method for subsurface sequestration of carbon in a subterranean zone includes forming a fluid-filled volume in the subterranean zone by injecting an aqueous into the subterranean zone and injecting a mixture comprising silicate nanoparticles suspended in an acidic solution having a pH of less than 4. Carbon in the form of carbon dioxide is injected into the fluid-filled volume such that a least a portion of the carbon is sequestered by precipitation of carbonate minerals. At least a portion of the carbonate minerals are formed from reaction of metal cations with bicarbonate formed from the carbon dioxide, and least a portion of the metal cations are a product of decomposition of the silicate nanoparticles in the acidic solution.

A method of making a cement composite can include contacting an aqueous solution comprising calcium ions with a carbon dioxide source producing a carbonated aqueous solution. Fine particles can be submerged in the carbonated aqueous solution to produce microaggregate particles comprising the fine particles coated with calcium carbonate. The microaggregate particles can be combined with cement particles to produce the cement composite. The cement composite can be used in cementing applications for hydrocarbon wells including for casing liners and well plugs.

A method of making a cement composite can include contacting an aqueous solution comprising calcium ions with a carbon dioxide source producing a carbonated aqueous solution. Fine particles can be submerged in the carbonated aqueous solution to produce microaggregate particles comprising the fine particles coated with calcium carbonate. The microaggregate particles can be combined with cement particles to produce the cement composite. The cement composite can be used in cementing applications for hydrocarbon wells including for casing liners and well plugs.

A gypsum-based composition of calcium sulfate hemihydrate with (a) alum and calcium carbonate and/or (b) zeolite and sodium percarbonate for making foamed gypsum slurry. A method to make foamed gypsum slurry from the composition. A method to make foamed gypsum product from the composition. A cavity wall having a cavity filled with the foamed gypsum product.

A gypsum-based composition of calcium sulfate hemihydrate with (a) alum and calcium carbonate and/or (b) zeolite and sodium percarbonate for making foamed gypsum slurry. A method to make foamed gypsum slurry from the composition. A method to make foamed gypsum product from the composition. A cavity wall having a cavity filled with the foamed gypsum product.

The present invention relates to a rapid-setting hydraulic binder composition and, more specifically, to a hydraulic binder composition, which contains tricalcium aluminate (C3A) and dodecacalcium heptaaluminate (C12A7), and thus is rapidly set, has an easily adjustable setting time, and is bio-friendly.

A method of producing a cementitious material includes combining a reaction mixture to form a slurry and curing the slurry to form the cementitious material. The reaction mixture may include a mineral mixture, an organic compound, and CO.sub.2. The mineral mixture may include calcium and the organic compound may be 3,4-dihydroxyphenethylamine, methyl salicylate, or both.

A method of producing a cementitious material includes combining a reaction mixture to form a slurry and curing the slurry to form the cementitious material. The reaction mixture may include a mineral mixture, an organic compound, and CO.sub.2. The mineral mixture may include calcium and the organic compound may be 3,4-dihydroxyphenethylamine, methyl salicylate, or both.

Methods and compositions for carbon dioxide (CO.sub.2) sequestration in a wellbore. A method includes locating a lost circulation zone in the wellbore during drilling. Methods may further include flushing drilling mud from the wellbore to prepare the lost circulation zone for lost circulation mitigation and injecting a cleaning solution into the wellbore. Then, injecting a composition for CO.sub.2 sequestration into the wellbore, where the composition may include a brine solution, an alkali and/or an alkaline compound, and a catalyst. The method may further include injecting a volume of CO.sub.2 into the wellbore, mineralizing the alkali and/or the alkaline compound and the volume of CO.sub.2 to produce an alkali and/or alkaline carbonate compound, injecting drilling mud into the wellbore and resuming drilling operations.