A cement slurry comprising a base for reducing the impact of an alkaline solution may be displaced into a wellbore and allowed to set. The base may comprise a metal carbonate that is soluble in water such as potassium carbonate. The cement slurry may further include cement, water, and a salt that is soluble in the water such as potassium chloride. The alkaline solution may be present in a formate-based drilling fluid displaced into the wellbore ahead of the cement slurry. Despite being contacted by such an alkaline solution, the thickening time of the cement slurry is long enough and the set time is short enough to provide for the formation of an impermeable mass in the annulus of the wellbore. The thickening times may range from about 4 hours to about 16 hours, and the set times may be less than about 24 hours.