Using 2D Petroleum Systems Modeling (TecLink^®) in Complex Tectonic Settings - Application to the Greater Cusiana Field, Colombia

Laurent de Walque¹, Carolyn Lampe², and Daniel Palmowski^2
1 TOTAL, 2 place de la Coupole, 92078 Paris La Défense Cedex, France,
[email protected]
² IES, Integrated Exploration Systems, Ritterstr. 23, 52072 Aachen, Germany

Tectonic and petroleum systems modeling is applied to better understand what drives hydrocarbon migration and accumulation in highly complex thrustbelt areas. The representation of such a complex structure including its petroleum systems can still be considered a challenge when put into a modeling frame work. PetroMod’s 2D TecLink^® allows to not only address the laterally and vertically changing geometry through time but also incorporates the full thermal evolution and petroleum migration. A two-dimensional, PVT-controlled, multi-component, 3-phase petroleum migration model demonstrates the integration of geometry changes, thermal history, maturation, migration and accumulation through time to understand the petroleum distribution in the area of the Cusiana Field, Colombia.

The study area lies in the Llanos Foothills in the eastern Cordillera of the Colombian Andes Mountains, 240 km northeast of Bogotá. The Cusiana Field is part of an asymmetric hanging-wall anticlinal trap formed during the Miocene/Holocene compressional deformation of the eastern Cordillera. The strata comprise a mixture of shallow marine and fluvial deposits, ranging from Upper Cretaceous to Pliocene in age. Three source rocks are considered in the study: the Cenomanian/Turonian Gachetá Fm., the Paleocene/Lower Eocene Los Cuervos Fm., and the lower Oligocene Carbonera Fm. The reservoir rocks include the lower Campanian Guadalupe Fm, the Upper Paleocene Barco Fm, and the Eocene/Oligocene Mirador Fm. The Oligocene Carbonera Group acts as a regional seal.

The model was constructed based on balanced GeoSec 2D^®sections trending NW-SE across the Cusiana Field. The total length of the section is 116 km at present day. Six paleo-sections, including pre- and post erosion geometries, served as a basis for the model, depicting a total shortening of the area through time of about 65 km. The model features ten fault blocks (present-day) that accommodate the structural framework and its development. Special attention was paid to the Cusiana trap geometry and its evolution through time. The model accounts for major faults in the area. The influence of fault transmissivity evolution upon petroleum migration (conduit or barrier to flow) has been evaluated to aid assessment of reservoir charging mechanisms. Temperature and vitrinite reflectance data derived from four wells, outcrop sampling along the section and regional studies, have been used to calibrate the model with respect to thermal maturity.

The model results show how the different source rocks contribute to the various reservoirs with respect to composition and phase of the generated petroleum. Petroleum properties, such as GOR and API, can be evaluated.

 

AAPG Search and Discover Article #90066©2007 AAPG Hedberg Conference, The Hague, The Netherlands

 

AAPG Search and Discover Article #90066©2007 AAPG Hedberg Conference, The Hague, The Netherlands