The Petroleum System in La Blanquilla and Tuy-Cariaco Basins, Offshore Venezuela

Pérez G, Adriana C.¹, Asdrúbal J. Bernal P¹ (1) PDVSA-Intevep, Los Teques, Venezuela

Detailed geochemical characterization of the petroleum system elements is an important component in the evaluation of the hydrocarbon potential in exploration areas. In this study, the origin and distribution of hydrocarbons and petroleum system of La Blanquilla and Tuy-Cariaco Basins, offshore Venezuela is established through use of source rock characterization, fluid analysis and 1D and 2D petroleum system modeling. These analyses were integrated with Bioestratigraphical, Sedimentological and Geophysical data.

Interpretation of the data in La Blanquilla Basin suggest that the fluid accumulated in silty and calcareous, deep water sandstones of Lower Miocene age (light oil, condensate and gas) might be correlated with a potential source rocks (shale) of middle or Lower Eocene ? age. Even tough source rock-fluid correlations were not possible, the data suggest that the potential Eocene source rock could only have reached the maturity to generate these fluids in the deepest part of the basin, located next to the structural highs were the fluid are accumulated.

In the Tuy-Cariaco Basin, the source rock generating the light oil accumulated in fined grain, depth water sandstones of upper Miocene age and the gas accumulated in platform (neritic) sandstones of Plio-Pleistocene age is interpreted to be a shale of Miocene age. The hydrocarbon generation potential of this source rock is located toward the Cariaco Through. The source rock is interpreted to generate in the South (Cariaco Through). The fluids expelled them migrate to the North and accumulate in anticlines structures.