Using a ChronoStratigraphic Unfolding Workflow to build an a priori model for Stratigraphic Inversion with accurate Horizon and Fault Fitting.
Résumé
The following work concerns the crucial step of building a 3D faulted a priori model to apply a model-based stratigraphic inversion of surface seismic data. Taking into account fault network areas is still a challenge and time consuming, so we describe in this paper how the 3D faulted surface framework and chrono-stratigraphic information could help us to achieve our goal.
The a priori model is in fact a series of 3D cubes filled by stratigraphic properties which will be used for further minimization processes during stratigraphic inversion. To be really valuable, in case of faulted areas, it is necessary to integrate accurately the seismic information properly on both side of each fault, depending on seismic to noise ratio of input seismic data. Then, to fill up the cubes with stratigraphic a priori properties, we have used a methodology based on the isometric flattening of each litho-stratigraphic units. By using shape functions we can define correspondence between each pixel of the seismic cube, i.e. from (X, Y, T) domain and its image in the deposition (U, V, D) domain of each unit.
We are presenting a general solution using a sealed surface Framework built from geological knowledge expression and horizon and fault picking. The resulting a priori model is filled, at a seismic scale, with a series of various properties like petro-physical and geometrical properties.