Quantitative methods taking into account the sedimentological characteristics will answer the needs of reservoir engineers. The paper proposed a geostatistical method for the conditional modelling of the facies of a sedimentary fluvio-deltaic series. This model was elaborated jointly by I.F.P. and the Paris School of Mines with the aim of modelling reservoir heterogeneities. From the sedimentological study contained in the paper by C. Ravenne et al., several simulations, conditioned by \"drill-core\" taken from the outcrop are presented. The block permeabilities are then calculated from the values given to the facies.