Abstract

RODRIGUES, JUAN et al. Geostatistical inversion of Post-stack seismic amplitudes. Rev. Fac. Ing. UCV [online]. 2007, vol.22, n.4, pp.59-67. ISSN 0798-4065.

In this work we present a method to jointly estimate acoustic impedance and total porosity by inverting seismic amplitudes and matching well-logged information. We combine geophysical, petrophysical and geological information in a two-scale model. The properties in the model are related across scales with the appropriate averages, i.e., the Backus average for compressional velocities and arithmetic averages for porosity and density. A major objective of the work is to combine the well-logged information of porosity and impedance with seismic information. With this combination we can improve the vertical resolution of the model in the regions of the volume influenced by the well data according to a spatial statistical model. In an example case we estimated the medium properties at 1ms interval, while the vertical resolution of a conventional seismic inversion is of the order of 6ms. The property volumes of porosity and impedance estimated with our technique jointly explain the seismic data and the well-logged data acquired in the area.

Keywords : Seismic inversion; Geostatistics; Optimization; Acoustic impedance; Porosity.