PETROLEUM POTENTIAL OF THE ARGENTINE CONTINENTAL MARGIN – DATA COMPILATION AND PSEUDO-WELL SIMULATION

The undrilled and underexplored passive continental margin off Argentina and Uruguay is characterised by seaward-dipping reflector (SDR) sequences which are interpreted to be dominantly effusive volcanics. Early Cretaceous rifting and breakup of the southern South Atlantic were accompanied, on its western side, by short-term, but widespread emplacement of 60-120 km wide SDR wedges along the continent-ocean boundary. These voluminous bodies may have had an influence on regional petroleum systems through the dissipation of their heat, their impact on the subsidence of adjacent basins, their potential sealing capacities, or through their characteristic internal geometry and the intercalation of potential reservoir facies. The structural similarity of the Argentine margin with hydrocarbon-producing volcanic rifted margins, such as those offshore Norway or Namibia, has stimulated comparisons regarding their resource potential.

This study is part of a project that aims at providing quantitative estimates of the in-place petroleum (oil and gas) volumes along the Argentine Margin. Ideally, this should procede via the calculation of potentially generated, migrated and trapped petroleum volumes and via a statistical evaluation of the certainties involved. For this purpose, quantitative input data are required. Gross volumes of potential source rock and reservoir lithologies are drawn from own seismic data, but other data (e.g. TOC, HI, maturity, porosity, seal integrity) are unknown from the target area. Consequently, this study relies heavily on indications from basins that are taken to be analogous with respect to the subsidence, sedimentary and paloceanographic evolution of the Argentine margin.

Source rock data from adjacent and remote basins with supposedly analogous depositional and thermal histories were compiled and used to simulate pseudo-wells along the Argentine margin. Preliminary results point to the existence of viable petroleum systems related to source rocks from pre-rift and early post-rift sequences known from adjacent basins.