3D High Resolution Seismic Model in Depth - A Relevant Guide for the “Andra” Deep Geological Disposal Project

The paper demonstrates the benefit of combining time-to-depth conversion of seismic horizons by Bayesien kriging, consistent seismic velocity model and elastic impedance in time for building a geological model in depth. The 3D field example illustrates the potentiel of the proposed depth conversion procedure for estimating a density model in depth. The geological model shows good agreement with logging data obtained at a reference well, one of the closest boreholes located in the vicinity of the 3D seismic area. Modeling of mechanical parametres such as shear modulus, young modulus indicates weak variability of parameters which confirm the homogeneity of the target formation ( Callovo - Oxfordian clay). 3D modelling of permeability index computed from seismic attributes ( instantaneous frequency, envelope, elastic impedance) and validated at the reference borehole shows promising potential for supporting hydrogeological simulation and decision making of safety evaluation.