SE Gulf of Mexico Deep Offshore -- Basin Evaluation by 3D Probabilistic Scenarios Modeling

By

 L. Vassalli¹, A. Corradi¹, C. Daturi¹

(1) ENI SpA - Agip Division, S. Donato Milanese, Italy

 The SE Gulf of Mexico is a truly unexplored area; the geology of this deep part of the Gulf of Mexico can be interpreted only by means of geophysical data since few direct geological data are available.

Due to the great uncertainty, 3D Basin Modelling packages, based on Monte Carlo simulations, can be utilized to evaluate the Petroleum System, by defining a range of possible hydrocarbon generation scenarios and by determining a set of geologically plausible hydrocarbon charge scenarios depending on other (carrier/seal permeability, the pressure regime, etc).

The combination of the regional background with the geological model, the Late Triassic-Middle Jurassic syn-rift lacustrine shales and the Lower Cretaceous dark laminated limestones can be postulated as the main source rock intervals. Assumed geochemical parameters have been derived partly from DSDP and onshore data, partly from typical lacustrine and shallow water source rocks geochemical database. Potential reservoirs can be identified through seismic interpretation in the Middle Jurassic nonmarine sediments and in the Lower Cretaceous shallow marine carbonates. The Upper Jurassic deep marine deposits and the Lower Cretaceous marly limestones can be assumed as the main seals.

The definition of the present basin thermal setting and its evolution through time has been carried out utilizing a Thermo-Tectonic modelling approach.

The assessment of the source rock potential in terms of hydrocarbon production has been pointed out simulating a 2D generation-expulsion modelling on different dip seismic lines to structural trends.