In this study, a certain zone of Libra oil field of the pre-salt region was selected to be analyzed for didactic purposes in order to simulate AVO responses. The region was modeled using seismic data, setting up a typical oil system with source rock (shale), reservoir rock (sandstone), and seal rock (salt). Thus, a set of parameters such as seismic wave velocity, density and Poisson's ratio for the studied zone was proposed. The AVO analysis allowed the classification of reflectors and the distinction of the geology for sandstones saturated with both water and gas.