| Interpreting the flow properties of saturated porous materials from their acoustic responses at low frequencies scale has been a goal of geophysics research for decades. This thesis describes Differential Acoustic Resonance Spectroscopy (DARS), a robust acoustic method we have developed for studying the flow properties of porous materials at kilohertz frequencies. The work is subdivided into five parts: Construct a low-frequency laboratory measurement system; Establish measurement methodology; Measure and analyze laboratory measurements; Develop an analytical model for dynamic diffusion in porous media; Verify the analytical model with a finite-element numerical approach.; The primary contribution of this study is that we estimate the effective compressibility of fluid-saturated porous media under a low-frequency, dynamic fluid acoustic load; we construct an analytical model linking the flow properties with the effective compressibility; and we propose a robust way to estimate the permeability of earth materials under dynamic flow conditions. The method is applied to a broad range of rock types. |
