Regional Geology, Tectonics, and Paleogeography of the Cretaceous Colombian Passive Margin Basins: A Predictive Lens Towards Unconventional Prospectivity

摘要

The Cretaceous passive margin deposits of Colombia form part of northern South America's most prolific hydrocarbon system, which highlights their source rocks as high-potential, self-sourced to hybrid Unconventional resource plays. This succession is characterized by thick and laterally extensive Type II(S)/III shales and carbonates of the Lower Cretaceous Basal Carbonates (sensu lato) and Upper Cretaceous Villeta/ Gachetá/La Luna/Navay formations, the latter group being broadly coeval with the Eagle Ford Formation of North America. Unlike the Eagle Ford, however, the Colombian basins' world-class source rocks experienced a subsequent complex tectono-stratigraphic evolution, which can either complete and enhance exploration and commercial viability or detract from it. Basement-involved shortening in Colombia's supra-subduction zone setting provided the regional framework for these basins to form and has a first-order control on key petroleum system elements and ultimately the location and size of unconventional sweet spots on the play scale. While many of Colombian onshore basins have been Conventionally explored and produced for nearly a century, the understanding of their source rock systems and how they will perform as unconventional plays, is still emerging. In this setting, three key regional evaluation methods that can help to predict resource play behavior are: 1. Unraveling younger structural activity and its superposition on Cretaceous paleogeography using palinspastic plate reconstructions to constrain original gross depositional environment and identify source rock accumulations of the highest quality and net thickness; 2.