The Lago Fuego field was discovered in 1989 by Occidental Petroleum (OXI) during the exploration of the Río Grande Sur Block. Until 2016, the main objective was the Springhill Formation. Below this productive sandstone, there is a volcanic and volcaniclastic complex called Serie Tobífera, which was historically considered as the economic basement. Based on the 2016 drilling campaign results, this unit became a primary target alongside Springhill Formation. This paper is aimed at showing how the integration of different tools and techniques made it possible to move forward in the state of knowledge of the Serie Tobífera in the Lago Fuego Block. To perform the rocks characterization, well logs - including nuclear, resistive, acoustic and magnetic tools analysis- were complemented with core data, side well cores and cutting. Furthermore, macroscopic descriptions focused on rock textures were critical for the volcanic succession characterization. Thin sections, laboratory petrophysical studies, scanning electron microscopy and chemical facies were also performed. The data set allowed us to identify different genesis and composition of rock bodies. Due to the importance of natural fractures in these low porosity and permeability reservoirs, their description and characterization were also included as part of the studies. These results and the identification of the tectonic events in this area, enabled the development of a predictive prospective model that includes mechanical facies and fracture intensity grids. These outcomes helped in decreasing the uncertainty of new prospects