Heavy to normal oils predominate in the basin. There is detectable relationship between API gravity and reservoir depth. Oils in this basin have fair to good quality with tendency to low API gravities due to biodegradation processes. In the central part of the basin (La Cira Infantas oilfield), there are crude oils affected by biodegradation processes that have removed the normal alkenes. In some wells, like La Cira- 1153, very light oils have been found, and are supposed to have been added during a second generation pulse. Most samples show immature to gas generation window conditions. Maturity increases in the Simití Formation and Basal Calcareous Group. Kerogen type is predominantly II. La Luna Formation constitutes the unit with the best hydrocarbon generation potential.