A cement composition based on a sulfoaluminate clinker is described, together with its use for agglomerating and inerting sediment/dredging sludge, and the relative inerting method and apparatus.

Lithium-containing cement admixtures including a calcium aluminate phosphate cement; a lithium-ion-containing compound; and an aqueous base fluid and methods of introducing the lithium-containing cement admixtures into a subterranean formation. The lithium-containing cement admixtures may further comprise an aluminosilicate or an additive including a set retarder, a set accelerator, a suspension aid, a density reducing agent, a fluid loss control agent, a defoamer, and any combination thereof.

Lithium-containing cement admixtures including a calcium aluminate phosphate cement; a lithium-ion-containing compound; and an aqueous base fluid and methods of introducing the lithium-containing cement admixtures into a subterranean formation. The lithium-containing cement admixtures may further comprise an aluminosilicate or an additive including a set retarder, a set accelerator, a suspension aid, a density reducing agent, a fluid loss control agent, a defoamer, and any combination thereof.

The present invention belongs to the field of composite materials, particularly to an underwater non-dispersible quick-setting and rapid-hardening cement-based composite material and the preparation method and application thereof. The material consists of the following raw materials in percentage by weight: 32%-34% of silicate cement, 8.8%-9% of calcium aluminate, 5%-7% of magnesium oxide, 0.5%-2% of sulfur trioxide, 0.2%-0.3% of polycarboxylate high performance water-reducing agent, 0.3%-0.7% of flocculant, 0.05%-0.2% of setting accelerator, 0.05%-0.2% of air-entraining agent, 0.05%-0.3% of rust inhibitor, 26%-31% of fine aggregate, 13%-18% of coarse aggregate, and 8.4%-8.5% of water. The material can be used for rapid repair of cement buildings in water conservancy projects, the repair material can be quickly set and the initial strength can be guaranteed.

The present invention belongs to the field of composite materials, particularly to an underwater non-dispersible quick-setting and rapid-hardening cement-based composite material and the preparation method and application thereof. The material consists of the following raw materials in percentage by weight: 32%-34% of silicate cement, 8.8%-9% of calcium aluminate, 5%-7% of magnesium oxide, 0.5%-2% of sulfur trioxide, 0.2%-0.3% of polycarboxylate high performance water-reducing agent, 0.3%-0.7% of flocculant, 0.05%-0.2% of setting accelerator, 0.05%-0.2% of air-entraining agent, 0.05%-0.3% of rust inhibitor, 26%-31% of fine aggregate, 13%-18% of coarse aggregate, and 8.4%-8.5% of water. The material can be used for rapid repair of cement buildings in water conservancy projects, the repair material can be quickly set and the initial strength can be guaranteed.

The present invention relates to a method for impregnating concrete with a non-aqueous electrolyte characterized in that an electric field is applied between electrodes mounted on the concrete surface and/or embedded in the concrete such that the non-aqueous electrolyte migrates into the concrete. Preferably, lithium ions are dissolved in the non-aqueous electrolyte.

The present invention relates to a method for impregnating concrete with a non-aqueous electrolyte characterized in that an electric field is applied between electrodes mounted on the concrete surface and/or embedded in the concrete such that the non-aqueous electrolyte migrates into the concrete. Preferably, lithium ions are dissolved in the non-aqueous electrolyte.

A method and agent to induce accelerated creep deformation of shale rock formations in the annular gap between a shale formation and non-cemented sections of a casing string have been developed. A fluid containing alkali silicate or a modified alkali silicate is added to the annular space between the shale rock formation and the casing string. The alkali silicate promotes creep deformation of the shale rock, effectively closing the annulus surrounding the casing. It has been found lithium silicate provides the strongest shale-casing bond and is the presently preferred material for closing abandoned wells.

Methods, compositions, and systems for cementing are included. The method comprises providing an extended-life calcium aluminophosphate cement composition comprising calcium aluminate cement, a polyphosphate, water, and a cement set retarder. The method further comprises mixing the extended-life calcium aluminophosphate cement composition with a cement set activator to activate the extended-life calcium aluminophosphate cement composition, introducing the activated extended-life calcium aluminophosphate cement composition into a subterranean formation, and allowing the activated extended-life calcium aluminophosphate cement composition to set in the subterranean formation.

Methods, compositions, and systems for cementing are included. The method comprises providing an extended-life calcium aluminophosphate cement composition comprising calcium aluminate cement, a polyphosphate, water, and a cement set retarder. The method further comprises mixing the extended-life calcium aluminophosphate cement composition with a cement set activator to activate the extended-life calcium aluminophosphate cement composition, introducing the activated extended-life calcium aluminophosphate cement composition into a subterranean formation, and allowing the activated extended-life calcium aluminophosphate cement composition to set in the subterranean formation.