Multifocusing Seismic Processing to Improve Poor Response Areas below Basalt Layers, Canadon Asfalto Basin, Argentina

The MultiFocusing technique (MF) has been successfully applied on a dataset from the Caadon Asfalto basin in Patagonia, onshore Argentina. The unconventional MF stacking method improves the quality of the seismic data considerably, especially in areas of the conventional 2D input dataset where shallow basalt layers obscure the structural configuration. The basic principles behind the MF technique are briefly described and an operational study is presented. The use of a supergather and the MF moveout compensation lead to a much better signal-to-noise ratio in poor data zones. A major advantage is that the MF algorithm does not need a detailed velocity model as input for the stacking procedure. The subsequent time migration, however, still requires a smoothed velocity field. The MF processing allowed the interpreter to generate a new hydrocarbon play concept for the early rift basin fill. It provided essential support to outline and mature a drillable exploration prospect. The alternative basin configuration is also confirmed by gravity and magneto-telluric modeling.