METHOD FOR ESTIMATING THE VOLUME OF CLAY (V _CLAY) ON THE BASIS OF THE FORMATION DENSITY, OF THE POROSITY AND OF THE ACOUSTIC VELOCITIES IN CLAY-SANDSTONE RESERVOIRS

摘要

Method of estimating the volume of clay (V_clay) characterizing a clay-sandstone reservoir, on the basis of the diagraphic recordings at the level of the well, the global density (ρ_b) and the velocities of the longitudinal (V_p) and transverse (V_s) waves and the porosity (ϕ). On the scale of the reservoir, one proceeds firstly with the estimation of the volumes of the acoustic velocities of the longitudinal (V_p) and transverse (V_s) waves and of the global density of the formation (ρ_b) on the basis of the seismic data processed in terms of amplitudes preserved by using a stratigraphic inversion. Thereafter one proceeds to the estimation of the volume of the total porosity (ϕ_t) on the basis of the acoustic velocities of the longitudinal (V_p) and transverse (V_s) waves and of the global density of the formation (ρ_b), which are generated by the inversion, using a multilinear relation. The volume of clay (V_clay) is estimated by this method by using the volumes of the seismic velocities (V_p) and (V_s), of the global density (ρ_b) and of the porosity (ϕ).