According to at least one embodiment of the present description, a cement slurry includes 1% to 90% BWOC of a cement precursor material based on the total weight of the cement slurry; and from 1% to 40% BWOC of a swelling additive based on the total weight of the cement slurry. The swelling additive comprises at least one micronized rubber, at least one distillate, and at least one solvent-refined heavy paraffinic.