f A New 3D Seismic Stratigraphic Methodology Applied to Turbiditechannel Systems

Seismic stratigraphic interpretation is a powerful method for analyzing the depositional history of the subsurface. However, the lack of support of such interpretation methods in the state-of-the-art tools limits its application. A novel technology allowing a highly automated procedure for seismic stratigraphic interpretation is presented (figure 1). The technology includes an automated high resolution extraction step of all the stratigraphic primitives prior to the interactive session. The technology supports a “dual domain” concept that enables to interpret transparently in the seismic domain and the chronostratigraphic time domain. The interpreter controls this mapping by selecting the appropriate set of stratigraphic primitives to define this transformation. The high resolution extraction step, referred to as extrema classification in figure 1, is based on Borgos et al., 2005. The output from this classification results in extrema patches (figure 1) from which the stratigraphic primitives might be defined. The method can be extended to active tectonic basins by including fault patches in the mapping between the seismic domain and the chronostratigraphic time domain (Pederson et. al, 2005). Figure 1 illustrates how faults supplement extrema patches to define the geological model. In complex geological settings, as e.g. stacked turbidite channel systems, the application of seismic stratigraphic interpretation might reveal a better understanding of the depositional settings. To demonstrate the potential of the new methodology we have applied it to a case from offshore Brazil. The four extracted stratigraphic surfaces are built from merged extrema patches. The obtained stratigraphic primitives refine the geological model and allow accurately placing the compartment boundaries and identifying presence of hydrocarbons (figure 2).