The Caballos Formation of Aptian-Albian age is an important reservoir in the Upper Magdalena Basin of Colombia. It has been studied at numerous outcrop localities along the basin margins. These outcrop studies which show considerable variation in Caballos depositional facies and reservoir properties need to be correlated with subsurface core data to develop a regional depositional framework and to examine regional variations in reservoir quality. This reservoir study of cores and outcrops was made to understand the depositional and diagenetic controls on reservoir quality in the Caballos Formation.
More than 3,200 feet of Caballos core from thirteen (13) wells were described and correlated with descriptions of Caballos outcrops at seventeen (17) locations. Analyses of biostratigraphy, petrology, and petrophysical properties were made to develop a regional time-stratigraphic framework, interpret depositional environment, and characterize reservoir quality. In addition, geochemical analyses of Villeta and Caballos shales were made to characterize source rock quality and thermal maturity. The results provide a better understanding of both source rocks and reservoirs in the Villeta-Caballos petroleum system of the Upper Magdalena Valley.
Cored wells and outcrop locations of the Caballos Formation were selected to provide regional and stratigraphic coverage in both the Neiva and Girardot Sub-Basins. New analyses including biostratigraphy, sedimentology, petrology, petrophysics, and geochemistry were integrated with available data to meet the following study objectives.
- Establish basin-wide time framework for the Caballos Formation
- Correlate Caballos units across the basin
- Characterize and interpret Caballos depositional facies
- Characterize petrophysical and petrographic properties and reservoir quality for each depositional facies
- Determine depositional and diagenetic controls on reservoir quality
- Determine location of Villeta/Caballos source rock kitchens
- Identify favorable areas for Caballos exploration
The results of this study are presented in a final synthesis report (Volume I) and in a number of data volumes (II and III). Analytical data are also provided in digital form.