Summary A practical methodology for characterizing unconventional plays is recommended in the exploration phase based on conventional logs, geochemical data and geomechanical analysis. The methodology consists of the lithological characterization of the formation to determine the mineralogical composition as well as the type of Shale, either with a predominance of carbonates, quartz or clays. Subsequently, the total organic carbon (TOC) is estimated using various methods and verified by the pyrolysis analysis to determine the potential hydrocarbons. Then, the total porosity (PHIT) is calculated by removing the effect that organic matter in each nuclear log. The volume of clay (Vclay) is estimated using the uranium-free spectral gamma ray logs, indicating alternatives in case spectral gamma ray is not available. After that, the total rock is modeled from a multimineral petrophysical analysis, entering TOC, PHIT and Vclay as input data and calculating the volume of minerals and fluids to characterize the rock. Finally, the rock brittleness index is estimated to identify the best zones suitable to fracture. The main objective of this characterization that includes petrophysics, geochemistry and geomechanics is to determine the best potential hydrocarbon zones, sometimes called "Sweet Spots" which also help in determining the landing zone for future horizontal wells.