Structural Model and Petroleum System of the Travi Area. Maturin Sub-Basin, Venezuela

Marien Parra¹, Patricia Delgado¹, Roberto A. Falcón¹, and Frederic Schneider^2
1Exploration, PDVSA, Puerto La Cruz, Venezuela
²Quantitative Geology Department, Institut Francais du Petrole (IFP), Rueil-Malmaison cedex, France

Maturin Sub-Basin is one of the most prolific hydrocarbon provinces of the world. Fields like Furrial, Jusepín and Orocual are now mature in exploration; however there are unexplored structures, to the north of the producing blocks. In Travi area, north of Furrial trend, some structures were identified during the 90s using 2D seismic. PDVSA drilled three wells and acquired 3D seismic between 2003 and 2006. Reserves of 600 million of barrels of oil and 2.5 TCF of gas were discovered.

Based on the new information a structural model was proposed through interpretation, section balancing and geochemical modeling. Travi structure is a N60E, north dipping monocline, associated to the deepening of Furrial thrust. Four fault families were identified: SO-NE high angle reverse faults, subparallel backthrusts, and compressive tear faults with orientations N40-60O and N40-60E.

Biostratigraphic information, integrated with seismic interpretation was considered to propose a kinematic model for the frontal part of the thrust belt. Early deformation was identified as soon as Early Miocene and simultaneous movement of different thrust sheets were established. This model has a big impact on the petroleum system. Two kitchens were developed and entered the oil windows during Early Miocene. Migration took place at Middle Miocene and maximum expulsion was reached around 11 Ma. Maturation process advanced from North to South as a consequence of tectonic and stratigraphic loading. A second expulsion took place during Late Miocene and is still active. The adequate timing and regional extension of the kitchens make Maturin Sub-Basing an still attractive exploration area. Main risks are associated with structural truncation of reservoirs to the north, against thrust faults, and decreasing in reservoir quality in deep objectives.

AAPG Search and Discovery Article #90078©2008 AAPG Annual Convention, San Antonio, Texas