Abstract

The Magdalena Fan is part of the Caribbean Basin of Colombia, an exploration frontier currently labelled as a gas-prone province. It is also one of the places with considerable chances of still finding billion barrel (in situ) hydrocarbon accumulations in Colombia. This chapter presents the elements that could assemble together to define an untested oil-play in the Magdalena Fan, which is described as Miocene turbidite lobes in frontal deformation anticlines, oil sourced from upper Cretaceous–Paleocene marine restricted shales.

The play combines the following components:

• Upper Cretaceous–lower Paleocene marine oil-prone source rocks (interpreted to be equivalent to the Cansona and Arroyo-Seco Formations), which according to a three dimensional basin model, expelled the majority of the oil from approximately 5 my to the present day.

• Hydrocarbon migration along sandy middle Ecocene carrier beds and vertically through faults.

• Four-way and thrust-faulted anticlines in the frontal slab of the Southern Sinu fold belt that are associated with the late Miocene to Plio–Pleistocene uplift (beginning at ca 7.5 my).

• Middle Miocene deep water turbidite reservoir composed of frontal splays that developed during the lowstand systems tract.

• Top seal formed by a fine-grained succession deposited during the transgressive systems tract.

There is still significant uncertainty related to the limited amount of data in the Magdalena Fan, especially in the deeper part of the stratigraphic section; nonetheless, the geologic model presented supports an exploration opportunity with the potential for unlocking considerable hydrocarbon resources.