Print this pageHydrocarbon Potential of a Duplex Interpretation Below the Giant Orocual Oil Field of the Eastern Venezuela Basin
Gilberto Sánchez1, Anahy Finno1, Jay Namson2, Jesús Hernández3, Linda Montilla1,
Lucila Hernández1, and Noelia Baptista1
1 PDVSA, División Oriente, Gerencia de Exploración, Venezuela, Puerto La Cruz, Venezuela
2 Davis & Namson Consulting Geologists, La Crescenta, CA
3 PDVSA, División Oriente, Gerencia Desarrollo de Yacimientos, Venezuela, Maturín, Venezuela
The Orocual Oil Field located in the Eastern Venezuelan Basin, represents an important prolific structure of this hydrocarbon rich area, with cumulative reserves of about 95 MMBls and 425 MMMPCG. The Orocual Field has long been known as a structurally complex area set between the thrusted El Furrial oil field to the south and the Pirital overthrust to the north. New interpretation suggests that there is an extensive untested thrust sheet below the producing field, on the regional structural analysis, integration of subsurface well data, interpretation of a regional 3D seismic survey and a series of structurally-modeled balanced cross sections.
The producing thrust sheet is complex and cut by older normal faults (some reactived), small slip back thrusts and thrust splays. The new interpretation shows the thrusted sequence within the Early Cretaceous Querecual Formation at its base and the base of the Early Miocene Carapita Formation at the top. The underlying prospective thrust sheet has never been drilled but is interpreted to involve the overlying repeated stratigraphic section. Previous structural models interpreted a thicker section composing the thrust sheet as well as higher angle faults to fill the area of structural relief created between the Orocual structure and the autochthonous section below. The new duplex interpretation is consistent with the low-angle thrust structure characteristic of the thrust front of the area involving 5-7 kms more slip than the previous model. In addition the interpretation is supported with forward kinematic structural modeling and geochemical petroleum system modeling.