Heavy Oil Stratigraphic Traps Modified by Contractional Deformation in the Colombian Eastern Foothills

Abstract

In this paper, we present the case study of the Chichimene and Castilla oil fields, which were originally discovered by Chevron, and were considered as separate structural traps. Here we show how the use of geophysics (seismic inversion), analysis of cores and field reservoir studies helped to redefine the concept of these accumulations. Our new data shows that Chichimene and Castilla might have originally been a single trap, including other anticlines to the south but were later modified by the combined effect of contractional deformation and hydro-dynamism. The new data suggests that the T2 unit, originally correlated with Eocene rock units, has in fact included Upper Cretaceous to Eocene reservoir units that pinch out to the east of Castilla. Multiple evidences seem to suggest that this configuration was the main trapping mechanism for a trap that already existed by the Early Oligocene period. The first charge events have been associated with Late Oligocene to Early Miocene migration from the Eastern Cordillera, when the reservoirs were shallower than today and therefore biodegraded. This new concept is opening additional exploratory opportunities along this prolific trend.

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