Tectonic Provinces and Different Types of Hydrocarbon Traps in the Maturin Subbasin, Eastern Venezuela Basin

Abstract

During the Oligo-Miocene, the transcollision of the Caribbean and South American plates, caused the northern flank of the Maturin Sub-basin to deform. This geodynamic process transformed the original passive margin basin into a foreland basin. As a result, the tectonic elements that distinguish this basin can be subdivided into three categories, the allochthonous block, the parautochthonous block and thrust belt, and the authochthonous block. The integrated interpretation of 7000 Km of seismic data and 25 wells has enabled us to elucidate the structural framework of the basin. A [open quotes]forward breaking[close quotes] sequence is proposed starting at the Pirital Thrust in the north and ending at the Furrial-Tejero Thrust in the south. However, the presence of a Post-Middle Miocene unconformity, folding of Early-Middle Miocene sediments and the development of a back thrust and its subsequent delta zone strongly suggests that movement towards the north also occurred. Between the Pirital and Tala faults, a lateral ramp known as the Urica fault, separates two zones that have been deformed by different mechanisms. The Urica fault has been interpreted by several authors as a dextral strike-slip fault. Hydrocarbons occur in three areas. The most important province occurs in the parautochthonous blocks with hydrocarbonsmore » occurring in cylindrical folds associated with the thrusts. To the south, conical folds associated with a strike-slip fault zone form good structural traps. The traditional Oficina fields lie still further south, in an area of normal faulting lightly affected by the Oligo-Miocene plate collision to the north.« less