Various embodiments disclosed relate to methods, compositions, and systems for enhanced oil recovery including a viscosifier polymer. In various embodiments, the present invention provides a method of enhanced oil recovery that can include obtaining or providing a composition that includes a viscosifier polymer. The viscosifier polymer includes an ethylene repeating unit including a —C(O)NH2 group and an ethylene repeating unit including an —S(O)2OR1 group, where the repeating units are in block, alternate, or random configuration. At each occurrence R1 can be independently selected from the group consisting of —H and a counterion. The method can include placing the composition in a subterranean formation downhole via an injection wellbore. The method can also include extracting material comprising petroleum from the subterranean formation downhole via a production wellbore.