Abstract: A cement mix for cementing the well casing within a wellbore which contains a synergistic blend of an alkali metasilicate and/or alkali silicate, aluminum silicate and either silica fume or micro silica quartz along with a Portland cement. The cement mix, when combined with mix water, may render a cementitious slurry having a density less than or equal to 11.5 pounds per gallon (ppg); the amount of mix water in the cementitious slurry being between from about 200 to about 560 percent by weight of cement (BWOC). The compressive strength of such cementitious slurries, when cured, is in excess of 100 psi, more typically in excess of 200 psi, after 72 hours at 130° F.

Abstract: A cement mix for cementing the well casing within a wellbore which contains a synergistic blend of an alkali metasilicate and/or alkali silicate, aluminum silicate and either silica fume or micro silica quartz along with a Portland cement. The cement mix, when combined with mix water, may render a cementitious slurry having a density less than or equal to 11.5 pounds per gallon (ppg); the amount of mix water in the cementitious slurry being between from about 200 to about 560 percent by weight of cement (BWOC). The compressive strength of such cementitious slurries, when cured, is in excess of 100 psi, more typically in excess of 200 psi, after 72 hours at 130° F.