Abstract:The microstructure of shale is more complex than conventional reservoir, while most of rock physics models for estimating P-wave and S-wave velocity are only suited to isotropic rocks at present. In consideration of the preferred orientations of clay particles and bedding parallel cracks, an anisotropic rock physics model was presented, combining the self-consistent approximation (SCA), the differential effective medium (DEM), the Backus average and the Brown-Korringa equation, and then S-wave velocity could be obtained by substituting the mineral content, porosity and pore aspect ratio into the constructed rock model. Three widely used isotropic models (Kuster-Toksoz theory, SCA and Xu-White model) and the constructed rock physics model are used to calculate P-wave and S-wave velocity for the practical shale area. It is illustrated that higher predicted accuracy can be found by the constructed rock physics model capturing the effect of anisotropy.