Several mature fields in Argentina still contain significant remaining hydrocarbon volumes that may represent economic redevelopment opportunities, once a methodology to locate and quantify them is established. In the case of the Barrancas Field, in the Cuyana basin, (Cretaceous Barrancas Formation as main reservoir) different geological scenarios, supported by dynamic simulations and history match, were used to propose a redevelopment plan, after 64 years of oil production and 48 years of water-flood development. Through a full-field history match, engineers could understand aquifer advancement along the western flank of the Barrancas anticline, identifying the best area with remaining hydrocarbons, to be tapped through a new field development plan. Due to the paucity of data in the poorly perforated western flank, a stochastic analysis of geologically plausible scenarios was used to capture reservoir facies thickness and areal distribution ranges. Based on the dynamic simulation results of the range of geological scenarios, project economics and decision trees were run and analyzed. New wells drilled during the 2014 to 2016 campaign, encountered the forecasted oil saturations, confirming the robustness of our redevelopment methodology which led to an increase in economic reserves and field production of ~25%.