Deformation Due to Shale Tectonic in Northwestern Venezuela

Nunez, Miguel, Amran Benguigui, Aisha Paez, Jorge Acosta, Jesus Rodriguez, Yamily Vergara, Erick Moreno, John Gonzalez, Marcos Romero, Saileth Cortez, PDVSA, Maracaibo, Venezuela

The Maracaibo basin in nortwestern Venezuela is the most profilic petroleum province in South America. High angle basement reactivated normal faults that generate listric faults in the cover were previously interpreted for the eastern part of the basin. Backstripping mat­uration and migation modelling hardly explained proved hydrocarbon ocurrence within this region using the structural control inserted by these basement faults.

Structues associated to shale tectonic such as turtles, weldings and isoleted subbasins are revealed by the new interpretation of the region. This tectonic setting implies the presence of a detachment level along which these structures were developed during the Cenozoic. At least two phases of deformation are interpreted for the region: lateral expulsion of shale due to differential loading and a later shale upwelling related to inversion episodes. The under­standing of the evolution of these new structural elements allows to postulate new migation paths which are favourable for hydrocarbon trapping and accumulation along the region.