This disclosure provides gypsum cement compositions which comprise an aggregate stabilizing mixture containing a combination of a polysaccharide gum and a polyacrylamide-gelatin blend, and methods for making and using these compositions, including pourable/pumpable floor underlayment slurries and methods for forming high strength underlayment on different substrates.

This disclosure provides gypsum cement compositions which comprise an aggregate stabilizing mixture containing a combination of a polysaccharide gum and a polyacrylamide-gelatin blend, and methods for making and using these compositions, including pourable/pumpable floor underlayment slurries and methods for forming high strength underlayment on different substrates.

The invention provides a high temperature resistant Portland cement slurry and a production method thereof. The high temperature resistant Portland cement slurry comprises the following components by weight: 100 parts of an oil well Portland cement, 60-85 parts of a high temperature reinforcing material, 68-80 parts of fresh water, 1-200 parts of a density adjuster, 0.1-1.5 parts of a suspension stabilizer, 0.8-1.5 parts of a dispersant, 3-4 parts of a fluid loss agent, 0-3 parts of a retarder and 0.2-0.8 part of a defoamer. The high temperature resistant Portland cement slurry has a good sedimentation stability at normal temperature, and develops strength rapidly at a low temperature. The compressive strength is up to 40 MPa or more at a high temperature of 350° C., and the long-term high-temperature compressive strength develops stably without degradation. Therefore, it can meet the requirements for field application in heavy oil thermal recovery wells, reaching the level of Grade G Portland cement for cementing oil and gas wells.

The invention provides a high temperature resistant Portland cement slurry and a production method thereof. The high temperature resistant Portland cement slurry comprises the following components by weight: 100 parts of an oil well Portland cement, 60-85 parts of a high temperature reinforcing material, 68-80 parts of fresh water, 1-200 parts of a density adjuster, 0.1-1.5 parts of a suspension stabilizer, 0.8-1.5 parts of a dispersant, 3-4 parts of a fluid loss agent, 0-3 parts of a retarder and 0.2-0.8 part of a defoamer. The high temperature resistant Portland cement slurry has a good sedimentation stability at normal temperature, and develops strength rapidly at a low temperature. The compressive strength is up to 40 MPa or more at a high temperature of 350° C., and the long-term high-temperature compressive strength develops stably without degradation. Therefore, it can meet the requirements for field application in heavy oil thermal recovery wells, reaching the level of Grade G Portland cement for cementing oil and gas wells.

Disclosed herein is a method of servicing a wellbore penetrating a subterranean formation, comprising: placing a cementitious composition of the type disclosed herein into the wellbore. The cementitious composition comprises a cement blend and water, wherein the cement blend comprises Portland cement and pozzolan, wherein the Portland cement is present in an amount of from equal to or greater than about 0.01 wt. % to equal to or less than about 25.0 wt. % based on the total weight of the cement blend.

Disclosed herein is a method of servicing a wellbore penetrating a subterranean formation, comprising: placing a cementitious composition of the type disclosed herein into the wellbore. The cementitious composition comprises a cement blend and water, wherein the cement blend comprises Portland cement and pozzolan, wherein the Portland cement is present in an amount of from equal to or greater than about 0.01 wt. % to equal to or less than about 25.0 wt. % based on the total weight of the cement blend.

The embodiments described herein generally relate to methods and chemical compositions for use with wellbore treatment processes. In one embodiment, a composition is provided comprising a cementitious material, a drilling fluid, or combinations thereof, and an additive composition comprising one or more components selected from the group of an aqueous insoluble lignin, a coke fine, a random tetracopolymer having the formula styrene-butadiene-acrylic-fumaric acid, a polyvinyl acetate, a surfactant composition, and combinations thereof.

The embodiments described herein generally relate to methods and chemical compositions for use with wellbore treatment processes. In one embodiment, a composition is provided comprising a cementitious material, a drilling fluid, or combinations thereof, and an additive composition comprising one or more components selected from the group of an aqueous insoluble lignin, a coke fine, a random tetracopolymer having the formula styrene-butadiene-acrylic-fumaric acid, a polyvinyl acetate, a surfactant composition, and combinations thereof.

The invention provides a carbon dioxide-resistant hydraulic cement composition. The inventive composition comprises a Portland cement, Class C fly ash and water. The Class C fly ash is present in the composition in an amount in the range of from about 5% to less than about 30% by weight based on the total weight of the cementitious components in the composition. In another aspect, the invention provides a method of cementing in a carbon dioxide environment. In yet another aspect, the invention provides a method of enhancing the recovery of a hydrocarbon fluid from a subterranean formation.

The invention provides a carbon dioxide-resistant hydraulic cement composition. The inventive composition comprises a Portland cement, Class C fly ash and water. The Class C fly ash is present in the composition in an amount in the range of from about 5% to less than about 30% by weight based on the total weight of the cementitious components in the composition. In another aspect, the invention provides a method of cementing in a carbon dioxide environment. In yet another aspect, the invention provides a method of enhancing the recovery of a hydrocarbon fluid from a subterranean formation.