The Centenario block is a mature field producing oil and gas, from sandstones and compact conglomerate sandstones from the Los Molles and Lajas formations. This field, located in the province of Neuquén (Argentina), is operated by the company PLUSPETROL S.A. The formations of interest are usually drilled to 8.5-inch diameters in a single run with a PDC bit. The empirical experience of the drillers, acquired over the years, indicates that both formations show differences in their behavior when drilled, with the ROP (rate of penetration) decreasing towards the northern sector of the field, where the rocks seem to be more resistant. This variability in the resistance of the rock is corroborated with 3D mapping carried out in the area for both formations. Both ROP and UCS (unconfined compressive strength computed from well logs) have been mapped. This corroborates the variability observed by the drillers and also allows the degree of correlation between both parameters to be analyzed, which is good.