Hydrocarbon manifestations have been reported in the southern portion of Cauca-Patía Basin. The general characteristics of stratigraphic sequence established for Cauca and Patía sub-basin suggest the existence of an active petroleum system (Figure 3).
The available geochemical data and the recently obtained information from outcrop samples indicate that the upper Cretaceous to Lower Eocene sedimentary units (Aguaclara, Peñamorada and Chimborazo formations) contain rock intervals with good characteristics to generate hydrocarbons (%TOC > 1 and Hydrogen index values > 300 mgHC / gTOC) and type II kerogen (Figure 4).
Hydrocarbon migration occurs along the Paleogene sandstones beds and fractures related to fault zones. Migration begins in late Miocene and continues to present time, as demonstrated by the occurrence of an oil seep at the Matacea creek.
The Cenozoic sedimentary cover contains coarsegrained clastic units (sandstone and conglomerates), ranging from late Paleocene to middle Miocene, and may be potential hydrocarbon reservoir rocks in the basin. Among these units are the Chimborazo, Ferreira, Mosquera and Cinta de Piedra formations, as well as some levels of Guachinte Formation.
The units, whose lithological characteristics represent the best regional seals in the Cauca-Patía Basin, are some fine grained volcaniclastic deposits interbedded in the Galeón and La Paila formations, and local intraformational clay levels interbedded with potential reservoirs.
In the Patía sub-basin the traps are structural type, and are associated with fault propagation folds. For the Cauca sub-basin, the deformation is less intense and it is associated with basement block tectonics, that generate stratigraphic traps associated with units wedging against the basement, and lateral closure generated against normal faults, sometimes reactivated as inverse faults.