A method for controlling loss circulation in a subterranean formation. The method includes circulating in a wellbore a nanosilica drilling fluid having a pH in a range of from about 8 to about 11 and a gel pH of less than 8, where the nanosilica drilling fluid includes an aqueous-based drilling mud and an alkaline nanosilica dispersion. The method also includes introducing into the nanosilica drilling fluid an amount of a chemical activator sufficient to produce a convertible drilling mud where the chemical activator is an acid and the pH of the convertible drilling mud is less than the gel pH. The method also includes allowing the convertible drilling mud to convert into the solid gel lost circulation material. A convertible drilling mud operable to convert into a solid gel lost circulation material is also provided.

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 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 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.

It discloses cement grinding aids prepared with waste antifreeze which comprises the following components in parts by weight: 20-75 parts of pretreated waste antifreeze, 5-40 parts of alkanolamine, 1-5 parts of acid solution, 3-12 parts of saccharide and 15-50 parts of water. The pretreated waste antifreeze is prepared by adding an alkaline solution into waste antifreeze to regulate the pH value, adding a flocculant, and stirring and standing; separating upper-layer oil, and then filtering to remove flocculent precipitates, thus obtaining a clear mixed solution.

It discloses cement grinding aids prepared with waste antifreeze which comprises the following components in parts by weight: 20-75 parts of pretreated waste antifreeze, 5-40 parts of alkanolamine, 1-5 parts of acid solution, 3-12 parts of saccharide and 15-50 parts of water. The pretreated waste antifreeze is prepared by adding an alkaline solution into waste antifreeze to regulate the pH value, adding a flocculant, and stirring and standing; separating upper-layer oil, and then filtering to remove flocculent precipitates, thus obtaining a clear mixed solution.

It discloses cement grinding aids prepared with waste antifreeze which comprises the following components in parts by weight: 20-75 parts of pretreated waste antifreeze, 5-40 parts of alkanolamine, 1-5 parts of acid solution, 3-12 parts of saccharide and 15-50 parts of water. The pretreated waste antifreeze is prepared by adding an alkaline solution into waste antifreeze to regulate the pH value, adding a flocculant, and stirring and standing; separating upper-layer oil, and then filtering to remove flocculent precipitates, thus obtaining a clear mixed solution.