Phil C. deGruyter¹, Schuman Wu¹, Miguel Mora¹, Peter Sadler¹, Eduardo Achem¹, Tomas Villamil², Mark Rowan³, Steve G. Franks⁴, Steve Bergman⁵

(1) Repsol-YPF, Englewood, CO
(2) Ecopetrol, Bogota, Colombia
(3) Rowan Structural Consulting, Boulder, CO
(4) RockFluid Systems, Inc, Plano, TX
(5) RockFluid Systems, Inc, Plano, CO

ABSTRACT: New Insights on the Eastern Cordillera, Colombia

The Eastern Cordillera represents the "heart" of Colombia's petroleum system, but in spite of providing the charge for giant oilfields (Cusiana, Cupiagua, Caño Limón) it is mainly viewed as an uplifted and eroded paleo-kitchen with little remaining exploration potential. It is one of the best examples of large-scale basin inversion, evolving from a 7000+m deep basin to a 5000m high Cordillera, but our understanding is limited by interpretational inconsistencies and lack of data. Prior to investing in costly regional seismic and wells, an effort is underway to produce an internally consistent model that fully integrates all the structural, stratigraphic and thermal elements with new geochronologic constraints, including fluid inclusion and AFTA data.

1) The extremely thick shallow water Cretaceous synrift and sag sequences have never been adequately explained. Either very large amounts of rift-induced accommodation space and sub-aerial paleo-topography existed by the end of the Hauterivian (>2000-3000 m) or active extension continuously created the necessary accommodation space during much more of the Cretaceous than previously considered.

2) Previous studies have wide discrepancies in the Cenozoic compressional phases in terms of inversion and high-angle faulting versus low-angle thrusting, the amount of shortening (~2x differences), the position of basement (differences of 1000s of meters) and the timing and sequence of the different compressional pulses and uplifts.

We provide new insights into subsidence, sedimentation, and tectonic evolution in the Mesozoic extensional and Cenozoic compressional stages of the Cordillera which have direct impacts on thermal and maturity models and hydrocarbon assessment for the region.

AAPG Search and Discovery Article #90906©2001 AAPG Annual Convention, Denver, Colorado