Patent ID: 8641818

Claim:
A subterranean formation cementing composition comprising: Portland cement; water in an amount sufficient to form a pumpable slurry; biowaste ash, wherein the biowaste ash does not include fly ash or rice hull ash, wherein the biowaste ash has been burned in a range of from about 2 hours to about 8 hours at a temperature in a range of from about 500° C. to about 700° C., and wherein the biowaste ash is present in the subterranean formation cement composition in an amount of about 1% to about 25% by weight of the Portland cement; at least one component selected from the group consisting of cement kiln dust, a natural pozzolan, metakaolin, shale, slag, zeolite, and combinations thereof; and at least one additive selected from the group consisting of a strength-retrogression additive, a set accelerator, a set retarder, a weighting agent, a lightweight additive, a gas-generating additive, a mechanical-property-enhancing additive, a lost-circulation material, a filtration-control additive, a dispersant, a fluid loss control additive, a defoaming agent, a foaming agent, a thixotropic additive, an oil-swellable material, a water-swellable material, and combinations thereof; wherein the subterranean formation cement composition has a density of less than about 13 pounds per gallon.