Cross-scale seismic rock physical attenuation model and method for predicating attenuation and dispersion

The invention discloses a cross-scale seismic rock physical attenuation model and a method for predicating attenuation and dispersion. The model simulates characteristics of underground oil-gas-bearing double-phase medium, and adopts the construction structure that the influence of a jet flow of a micro-scale fracture in a BISQ elastic wave prorogation theory is introduced under the framework of a macro-scale Biot double-phase medium wave prorogation theory; a periodic stratification White module under mesoscale is introduced, so as to ensure that water-bearing stratums and gas-bearing stratums are alternatively and periodically overlaid; the horizontal direction of each stratum is infinitely extended; each stratum adopts isotropic medium; the thickness of each stratum is far less than seismic wavelength and is greater than the particle size; the control equation of each stratum adopts a BISQ elastic wave prorogation equation, so that the cross-scale seismic rock physical attenuation model is constructed. The model comprises three scale attenuation mechanisms, namely a micro-scale Biot flow, a mesoscale local flow and the micro-scale jet flow. The invention further discloses a method for predicating the longitudinal wave attenuation and dispersion of the model. A predicated attenuation value is very consistent with an attenuation value measured by experiments.