Compositions and methods are given to prevent, alleviate and remedy water blocks and gas blocks (condensate block or condensate banking). Wettability modifiers are contacted with the formation to change the surfaces from water wet or oil wet to intermediate wet or gas wet. Preferred wettability modifiers include partially or completely fluorinated surfactants or polymers, for example fluorosilanes such as perfluorosilanes, urethane oligomers containing perfluoro alkyl moieties, fluoroacrylates, and fluoroalkyl containing terpolymers or their mixtures. Other examples include surfactants, for example viscoelastic surfactants such as cationic surfactants such as quaternary amines, and zwitterionic surfactants, such as betaines, optionally mixed with co-surfactants.