Structure, stratigraphy, and petroleum potential of the deepwater Colombian Basin, offshore northern Colombia

Abstract

We have defined the structure and stratigraphy of the central area of the Colombian Basin — offshore of the northern Caribbean coast of Colombia — using approximately 8400 line km of depth-converted 2D seismic data assembled from academic and industry sources. We integrate information from offset deep sea drilling program and ocean drilling program wells into a structural and stratigraphic model of the Colombian Basin, identifying the key elements of a petroleum system. These elements are (1) Upper Cretaceous marine shale source rock, (2) Middle to Upper Miocene (16–5.3 Ma) basin-floor fans associated with the Magdalena fan turbidite system, (3) structural traps and stratigraphic traps, and (4) sealing intervals formed by Miocene hemipelagic marine shale associated with sea-level high-stands. We extend a previously recognized trap type for the Colombian margin to include stratigraphic traps within the distal Miocene Magdalena fan section. We base our interpretations upon seismic observations of amplitude anomalies conformant with structures; fluid migration pathways along faults; and bright, laterally continuous, and low-impedance seismic reflectors. The primary risk for the exploration potential of the area is the presence of a laterally extensive Upper Cretaceous source rock within the main Colombian basin depocenter. The 1D burial history models and 3D basin modeling indicate that a source rock of this age and at this stratigraphic level would have expelled hydrocarbons during Middle to Late Miocene from the deepest part of the basin and may continue to expel hydrocarbons in the present day.