The petroleum system of the central Perija fold belt, western Venezuela

The timing of hydrocarbon migration relative to trap formation remains a factor in evaluating the exploration potential of the Perija fold belt on the west flank of the Lake Maracaibo Basin. Based on the data from this article, there is evidence of structural traps being filled by two oil migration events. At least four major events of deformation have been identified in the area from the Late Cretaceous to the Holocene. The first event is Late Cretaceous in age and characterized by compressional structures. The second event is characterized by extensional features and occurred from the Late Cretaceous to the middle Eocene. The third and fourth events are characterized by compressional structures that developed during the late Eocene and late Miocene-Holocene, respectively. Based on oil-oil and oil-source rock correlations and one-dimensional (1-D) basin modeling, two phases of oil generation and migration are proposed as responsible for oil accumulation in the central Perija fold belt. The first phase occurred from a kitchen of late Paleocene-late Miocene age located to the west-southwest of the study area. The second phase occurred during the middle Miocene-Holocene from a kitchen located to the east of the study area. The older kitchen is responsible for oil accumulations found in the Upper Cretaceous traps. The younger kitchen is responsible for possible oil accumulations in traps of both Cretaceous and Tertiary reservoirs located in the eastern part of the study area.