Based on review of previous information and correlation of 7 lithostratigraphic sections from well data, it was possible to establish the presence of channels in fluvial environments of the Mugrosa Formation, with good lateral continuity, in the B and C zones, in the Middle Magdalena Valley Basin (VMM). The results of well log interpretation (NSP logs) indicate the presence of channel sands and proved the previous sedimentological model of the field. In the sedimentological model proposed, zones B and C (Mugrosa Formation) show a very good lateral continuity of sands. The reserve calculations of original oil in place (OOIP) and original gas in place (GOES) indicates that the largest reserves of oil and gas are located in the zone C, with reserves of 118 million bbl and 33.9 Gigas of cubic feet respectively.