Hydrocarbon Prospectivity within the Interval “A” of the Villeta Formation in the Putumayo Foreland Basin

Abstract

Summary The Putumayo Sub-Basin in southwestern Colombia is a structurally complex hydrocarbon province within the Andean foreland system. The Upper Cretaceous Villeta Formation, acting as a source rock, reservoir, and regional seal, presents significant hydrocarbon generation and expulsion potential. However, Interval “A”, a key reservoir target, remains insufficiently characterized. Recent resource assessments estimate prospective resources of up to 820 MMBOE, emphasizing the need for further exploration. This study integrates well log data and seismic interpretations from 2D and 3D datasets to refine the structural framework, accommodation geometry, and hydrocarbon prospectivity of Interval “A”. The analysis reveals that fault-controlled traps are the dominant structural play types, with compressional structures in the wedge-top zone and extensional features in the foredeep region. Results suggest that faulted anticline traps in the foothills have uncertain viability, whereas normal fault-bounded closures in the foredeep are more promising exploration targets. These findings contribute to a better understanding of the depositional and structural evolution of the Putumayo Sub-Basin, providing a framework for optimizing future hydrocarbon exploration strategies.