New seismic wave model for tight reservoirs: Incorporating non-Darcy flow and fractional viscoelasticity

Seismic wave propagation in porous media is accompanied by frictional energy loss caused by the relative motion between the solid skeleton and pore fluids. In tight reservoirs, this process is more complex because extremely small pores and throats commonly induce nonlinear fluid flow. Meanwhile, most available wave propagation models are still based on Darcy’s law, therefore they are unable to fully capture the nonlinear flow behavior that occurs in the narrow pores and throats of tight reservoirs, as well as its influence on wave-induced dissipation. To characterize nonlinear seepage, a non-Darcy flow mechanism is incorporated into the model. Furthermore, tight reservoirs commonly contain a large umber of poorly connected or nearly isolated pores, in which fluids are trapped within the solid framework and cannot undergo significant seepage. Such trapped fluids are more appropriately regarded as part of an equivalent solid matrix that undergoes internal friction under wave excitation. This effect is further described by introducing a fractional viscoelastic mechanism. Based on these considerations, a new model is proposed to describe seismic wave propagation in tight reservoirs by integrating the effects of non-Darcy flow and fractional viscoelasticity. Plane-wave analysis and numerical examples demonstrate that the proposed model can describe dispersion and attenuation over a broad frequency range by incorporating multiple dissipation mechanisms. Comparisons with experimental data on tight cores confirm that the proposed model accurately predicts the phase velocities of seismic waves. Although this model provides a more accurate and physically consistent framework for seismic wave propagation in tight reservoirs, it is still limited to isotropic media and requires further development for anisotropic conditions such as fractured reservoirs.. Document Type: Original article Cited as: Bu, F., Yang, D., Wen, J. New seismic wave model for tight reservoirs: Incorporating non-Darcy flow and fractional viscoelasticity. Advances in Geo-Energy Research, 2026, 19(3): 285-295. https://doi.org/10.46690/ager.2026.03.07