Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: A variety of methods are disclosed, including, in one embodiment, a method of cementing comprising: introducing a pipe string into a well bore such that an annular space is defined between the pipe string and a wall of the well bore, wherein an annular structure is coupled to the pipe string, and wherein the annular structure comprises an expandable material; and introducing a cement composition into the annular space, wherein the cement composition comprises cement, water, and a component capable of responding to a crack formed in the cement composition after setting to inhibit flow of fluid through the crack. In certain embodiments, the method further comprises choosing the cement composition based at least partially on an analysis of well incidents.

Abstract: Methods for performing cementing operations in a subterranean zone under high temperature conditions include forming a cementing composition having a density of less than about 10.5 pounds per gallon, pumping the cementing composition into the subterranean zone by way of the well bore and allowing the cementing composition to set therein. The cementing composition includes calcium aluminate, water, and a lightweight additive having a specific gravity of less than about 0.70.

Abstract: Compositions for performing cementing operations in a subterranean zone under high temperature conditions have a density of less than about 10.5 pounds per gallon, and include calcium aluminate, water, and a lightweight additive having a specific gravity of less than about 0.70.

Abstract: Foamed cement compositions comprising density reducing additives and methods of making and using the same are disclosed. In one embodiment, a method of cementing is disclosed. The method of cementing comprises preparing a base cement composition comprising a cement, a water, and a density reducing additive, wherein the base cement composition comprises a base density. The method further comprises introducing a gas to the base cement composition to provide a cement composition having a density less than the base density and allowing the cement composition to set.

Abstract: Methods of making a cement composition include combining a liquid additive comprising lightweight beads and fluid with a cement, wherein the liquid additive is substantially absent of a water absorbing material. The liquid additive may further comprise a dispersant. A mass ratio of the fluid to the lightweight beads in the liquid additive may be less than or equal to about 1:1. The liquid additive may be introduced to a delivery pump that supplies water to a cement mixing head for producing a cement slurry. Alternatively, the liquid additive may be introduced to a cement slurry as the slurry is being pumped into a wellbore. Systems for transporting the liquid additive include a recirculating pump for moving the liquid additive from the bottom of a vessel to the top of the vessel, thereby causing floating beads to be mixed down in the liquid additive.

Abstract: In an embodiment, the shelf life of lightweight beads to be used in a cement composition may be extended by combining the lightweight beads with a fluid such as water to inhibit the lightweight beads from forming an agglomeration while they are being stored or transported. In another embodiment, lightweight beads that have already formed an agglomeration may be revitalized for use in a cement composition by adding a fluid such as water to the lightweight beads to reduce a size of the agglomeration. The agglomeration may originally have a width greater than or equal to about 1 inch. Adding the fluid to the lightweight beads may cause at least a portion of the beads to separate from the agglomeration into individual beads having a width of less than or equal to about 200 microns.