Compositional, geochemical and petrophysical shale play characterization of the Upper Cretaceous in southern Middle Magdalena Valley (MMV) basin, Colombia

Abstract The compositional, geochemical and petrophysical characterization of a stratigraphic section from the Coniacian-Campanian in the South of the Middle Magdalena Valley basin allowed identifying the potential of this area for unconventional shale reservoirs. Siltstone facies composed of bio-mudstone with organic matter and micrite, and silty mudstone microfacies with foraminifera, showed the best conditions. Rock-Eval results showed a Type II Kerogen with TOC values that range between 2% and 4% and thermal maturity of 0.8% Ro, which demonstrates an optimal mat urity level for liquid hydrocarbon generation of this section. Compositionally, the upper part is characterized by high quartz content, whereas the middle section has high calcite content enhancing the mechanical properties of the rock in the event of hydraulic fracturing. The petrophysical analysis indicated optimal values for intergranular porosity favoring hydrocarbon storage. Data integration indicated at least two intervals with high potential for shale oil within the sequence studied.