AAPG ANNUAL CONFERENCE AND EXHIBITION
Making the Next Giant Leap in Geosciences
April 10-13, 2011, Houston, Texas, USA
Petroleum System Modeling Implications in a Prospect Geological Risk, Western Interior Range, Venezuela
(1) Exploration, PDVSA, S.A., Puerto La Cruz, Venezuela.
(2) Jackson School of Geosciences, Austin, TX.
The present report is an appropriated example of petroleum system modeling in exploratory frontier areas, to study an attractive prospect of 200 Km2 located in the western end of the Interior Range, close to the productive fields (Quiamare and Anaco). The risk for timing between the hydrocarbon expulsion and formation of the trap histories has been interpreted using 1D model analysis. In this opportunity 3D petroleum system modeling was used to provide a low risk prediction prospect model.
The structural and forward modelling allowed to determine the high risk of timing taking into account the following aspects: 1- The structure was formed after 16 Ma (Middle Miocene), 2- The thermal maturity level for the Cretaceous source rock has been inferred as high (>2%) in present expulsion area, by geodynamic and geochemical interpretation, and 3- The previous 1D model shows that the maximum expulsion peak from Cretaceous source rock was close to 20 Ma.
Several calibrations performed using subsurface and outcrop data (BHT, %Ro, porosity, hydrocarbon saturation levels in known areas) provide reliability in this 3D model. The results show, that the trap was 70% thrusted at 15.0 Ma and the maximum expulsion phase of generated hydrocarbon from the Cretaceous source rock occurred between 16.0 and 11.8 Ma.
Due to the understanding of spatial and time evolution of the source kitchen area and the relevance of 3D Petroleum System Modeling, the geological risk in the prospect was assumed considerable lower than the one interpreted from 1D model.