Patent ID: 7008479

Claim:
A cement composition comprising: a hydraulic cement; water; an additive comprised of carboxymethylhydroxyethyl cellulose (CMHEC) having in the range of from about 0.62 to about 2.21 moles of hydroxyethyl substitution and in the range of from about 0.44 to about 0.52 degrees of carboxymethyl substitution, and a 2% by weight aqueous solution of the CMHEC has a Hoppler viscosity in the range of from about 55 mPa.s to about 359 mPa.s; a gas; and a foaming and foam stabilizing surfactant mixture comprising an ethoxylated alcohol ether sulfate; cocoylamidopropyl betaine, and cocoylamidopropyl dimethyl amine oxide.