Methods for treating fluids used in the production and/or transport of petroleum products and natural gas, and methods for the removal of acidic gases encountered in fluids used and encountered in such operations are provided. In one embodiment, the methods include introducing a treatment fluid including a polymeric swellable acid scavenger that includes at least one polymeric composition into a wellbore penetrating at least a portion of a subterranean formation in which an acidic gas, an acid-containing fluid, or both, are present.