Stratigraphic Traps in the Llanos Basin of Colombia – Styles and Petroleum Systems

Abstract

The Llanos Basin is a foreland basin located to the east of the Colombian Eastern Cordillera. In this paper, we support the view that most important heavy oil fields in this province are associated with stratigraphic trapping mechanism mostly charged during the Late Oligocene - Early Miocene period from currently uplifted kitchens, located to the west. Chichimene and Castilla, with more than 8 billion barrels in OOIP together, are basement involved anticlines that were originally charged before the main Late Miocene to recent trap formation event. The original trap is associated with a stratigraphic pinch-out. Rubiales is located ca. 250 east of the main modern kitchens; we consider that it is a trap originally related to the stratigraphic pinch-out of the Oligocene C7 reservoir unit, but it was later modified by hydro-dynamism. Other emerging types of traps are the distal stratigraphic pinch-outs of Eocene to Oligocene units (Hamaca, Rio Ariari) and the so-called buried hills play, recently drilled by Ecopetrol. The variable success in this region is related to the early charge from paleo-kitchens, involving a very long residence time in the traps, favoring biodegradation, which partially destroys the accumulation and makes the hydrocarbon more viscous. Additionally, there is a need to explore these plays with 3D seismic data.

AAPG Datapages/Search and Discovery Article #90323 ©2018 AAPG Annual Convention and Exhibition, Salt Lake City, Utah, May 20-23, 2018