Measurement and estimation of seismic attenuation for near-surface site characterization

Seismic attenuation is a fundamental parameter on the comprehension of the viscoelastic real behavior of the medium. Characterization of the ability of materials to transmit and dissipate seismic waves is even important for petrophysical descriptions of reservoir rocks. The purpose of this work is to investigate the reliability of the rise-time and the spectral ratio methods for estimation in a seismic downhole campaign, to obtain accurate profiles. In this study, we applied two different methods to estimate attenuation. We used a standard spectral ratio technique to obtain the frequency independent and then compared the results to obtained in the time domain from rise-time measurements. Most of the borehole attenuation studies presented in literature are carried out for hydrocarbon exploration. The main contribution of the present work is to apply the two most used attenuation estimation methods to near-surface data. They include two techniques to determine the material damping ratio of the soil based on the downhole (DHT) test, and other two for attenuation and dispersion curves from MASW testing.