Study of wave-induced fluid flow (WIFF) became actual in geophysics last years, because attenuation caused by this effect can serve as indicator of fractured highly-permeable reservoirs. In our work we model two-scale fractured domains with small scale fractures forming percolating clusters. Statistical geometry analysis and numerical wave propagation simulations using finite-difference approximation of Biot's dynamic equations were done to estimate seismic attenuation and investigate the dependence of attenuation due to WIFF on percolation length. Theoretical predictions of at tenuation due to scattering are also provided. Obtained estimations demonstrate sufficient correlation between fracture connectivity and attenuation of waves propagating in considered fractured media.