Centralizers are run during cement jobs to ensure the casing is positioned evenly in the middle of the wellbore. This is important because cement should be distributed evenly around the casing annulus to ensure an adequate seal between the casing and formation. An uneven cement job can lead to contaminated cement or an inadequate seal which can cause drilling fluid to leak into a section of the formation that is supposed to be sealed off. Centralizers are especially important in deviated sections of the wellbore because the casing will tend to ride on bottom. Depending on its class, a centralizer can be outfitted with hinged and slip-on designs, as well as stop collars, wire scratchers and other accessories.