Patent ID: 8598093

Claim:
A cement composition comprising: cement; nano-silica in an amount of about 0.01% to about 1.5% by weight of the cement, wherein the nano-silica has a particle size range of about 5 nanometers to about 20 nanometers; an aqueous rubber latex in an amount of about 5% to about 20% by weight of the cement; a latex stabilizer in an amount of about 10% to about 20% by weight of the latex, wherein the latex stabilizer comprises a material selected from the group consisting of a sulfonate and a sulfate; and water in an amount of about 35% to about 70% by weight of the cement, wherein the cement composition has a density of about 8 pounds per gallon to about 17 pounds per gallon, and wherein the nano-silica is not colloidal and is essentially free of silica fume.