Methods for producing a swellable packer in a downhole environment are provided. A method includes introducing a treatment fluid containing a polymeric composition into a wellbore within the downhole environment and exposing the polymeric composition to an acid to produce a swollen polymeric material within the downhole environment. The polymeric composition contains a reaction product of at least one or more monomers, one or more comonomers, and one or more crosslinkers. The acid can be in situ formed from an acid precursor introduced into the downhole environment.