Abstract: Methods of cementing in subterranean formations, cement compositions, and methods for making the compositions are provided. A cement slurry is passed into a subterranean formation, and a swelling agent is passed into the subterranean formation to reduce an amount of water flowing into the cement slurry. The swelling agent may be combined with a carrier fluid before being displaced into the subterranean formation. Alternatively, the swelling agent may be pre-mixed with the cement slurry to form a new cement composition, followed by displacing the cement composition into the subterranean formation. The swelling agent is present in an amount effective to, upon absorption of water and swelling to form a gel mass, substantially block the flow path of the water into the cement composition or reduce losses to low pore pressure intervals, thereby preventing the integrity of the cement composition from being compromised or lost to voidage, fractures, fissures, etc.

Abstract: A method and composition is provided for a relative permeability modifying polymer for use with drilling fluids that comprises a water soluble polymer formed from a hydrophobic or hydrophobically modified hydrophilic monomer and a hydrophilic monomer. In an alternative embodiment, a method is provided for producing a water soluble polymer formed from a hydrophilic monomer for use as a relative permeability modifying polymer.

Abstract: The present invention includes a method for recovering oil from a reservoir. This method comprises passing a swelling agent into a permeable zone of the reservoir that allows fluid to flow between an injection well and a producing well. An aqueous solution is passed into the reservoir to contact the swelling agent, thereby causing the swelling agent to swell and substantially block the permeable zone. One or more injectants are passed into the reservoir to remove oil therefrom. The swelling agent inhibits the injectants from passing through the permeable zone, ensuring that the injectants pass through the areas of the reservoir containing oil.