A lost circulation material (LCM) is provided having an alkaline nanosilica dispersion and an ester activator. The alkaline nanosilica dispersion and the ester activator may form a gelled solid after interaction over a contact period. Methods of lost circulation control using the LCM are also provided.

A lost circulation material (LCM) is provided having an alkaline nanosilica dispersion and an ester activator. The alkaline nanosilica dispersion and the ester activator may form a gelled solid after interaction over a contact period. Methods of lost circulation control using the LCM are also provided.

A lost circulation material (LCM) is provided having an alkaline nanosilica dispersion and an ester activator. The alkaline nanosilica dispersion and the ester activator may form a gelled solid after interaction over a contact period. Methods of lost circulation control using the LCM are also provided.

Methods and compositions for a foamed treatment fluid in a wellbore. A method of treating a lost circulation zone comprising: introducing a foamed treatment fluid into a lost circulation zone in a subterranean formation, wherein the foamed treatment fluid comprises: a cement; a viscosifying agent; a thixotropic additive; a foaming surfactant; a gas; and water; allowing the foamed treatment fluid to set in the lost circulation zone to seal the lost circulation zone. A foamed treatment fluid comprising: a cement; a viscosifying agent; a thixotropic additive; a foaming surfactant; a gas; and water.

Compositions for foamed treatment fluids are disclosed. The foamed treatment fluid may comprise a cement, a viscosifying agent, a thixotropic additive, a foaming surfactant, a gas, and water. The foaming surfactant may comprise a polyethylene glycol alkyl ether (C.sub.5-C.sub.10), sulfate ammonium salt.

Cement slurries are prepared that comprise water, a hydraulic cement, particles of an oil-absorbent particles and non-swellable hydrophobic particles. The particles are present in an amount sufficient to alter a property of a non-aqueous drilling fluid. The cement slurry is placed in a subterranean well, whereupon the slurry contacts residual drilling fluid on casing and formation surfaces. The oil-absorbent particles and hydrophobic particles in the cement slurry may reduce the mobility of the drilling fluid, thereby improving zonal isolation.

Cement slurries are prepared that comprise water, a hydraulic cement, particles of an oil-absorbent particles and non-swellable hydrophobic particles. The particles are present in an amount sufficient to alter a property of a non-aqueous drilling fluid. The cement slurry is placed in a subterranean well, whereupon the slurry contacts residual drilling fluid on casing and formation surfaces. The oil-absorbent particles and hydrophobic particles in the cement slurry may reduce the mobility of the drilling fluid, thereby improving zonal isolation.

A type of composite material where the matrix material and additive are held together by covalently or non-covalently bound ligands is described. A particularly useful composite material covered by the present invention is a carbon nanotube-reinforced composite material where the matrix consists of a polymer, covalently attached to a linker, where said linker is non-covalently attached to the carbon nanotube.

Methods for the preparation of such composite materials are provided.

A lost circulation material (LCM) is provided having an alkaline nanosilica dispersion and a polyester activator. The alkaline nanosilica dispersion and the polyester activator may form a gelled solid after interaction over a contact period. Methods of lost circulation control using the LCM are also provided.

A lost circulation material (LCM) is provided having an alkaline nanosilica dispersion and a polyester activator. The alkaline nanosilica dispersion and the polyester activator may form a gelled solid after interaction over a contact period. Methods of lost circulation control using the LCM are also provided.