This undergraduate thesis evaluated the coalbed methane potential of the Eocene–Oligocene Loreto Formation and the Miocene El Salto Formation within a 720 km² area of the Magallanes Basin. The research was conducted as part of ENAP’s coalbed methane exploration project and incorporated data from two exploratory wells together with information from previously drilled wells.
         The study integrated core and cutting descriptions, geophysical well logs, stratigraphic correlations, and isopach mapping with petrographic and geochemical analyses of the coal. Methane content was determined through direct core-desorption testing, including estimates of lost, desorbed, and residual gas. Additional analyses included adsorption isotherms, maceral composition, vitrinite reflectance, proximate and ultimate analyses, coal density, and seam thickness. These datasets were integrated in Petrel to characterize the subsurface distribution and reservoir properties of the coal-bearing intervals and estimate gas in place.
        The analyzed coals are generally low-rank, ranging primarily from lignite to subbituminous coal, and are dominated by vitrinite. The Loreto Formation exhibits more favorable reservoir characteristics, including lower ash content, higher methane content, and gas saturation near or slightly above its calculated adsorption capacity. In contrast, the El Salto Formation contains more mineral matter, lower gas concentrations, and undersaturated coal seams.
     Methane content generally increases with depth and with higher proportions of volatile matter, fixed carbon, and clarain, while decreasing with increasing moisture, ash, and durain content. Estimated gas-in-place volumes range from 1.17 to 1.45 Tcf in the Loreto Formation and from 750 to 913 Bcf in the El Salto Formation. These estimates represent gas contained within the coal-bearing formations rather than technically recoverable reserves.