Effect of fluid viscosity and saturation on the ultrasonic velocities in a Fontainebleau sandstone

Azar Khalatbari (1) , Dung Vo-Thanh (1) , Jean-Paul Poirier (1)

1 IPGP - Institut de Physique du Globe de Paris

Simultaneous measurements of the P- and S-wave velocities at 1MHz frequency as a function of temperature from −80°C to 80°C have been made in a Fontainebleau sandstone saturated with glycerol. We investigated 8 saturation degrees, from fully saturated to almost dry state. Generally, the velocity decreases with increasing temperature; it is large between ≈ −40°C and ≈ 40°C. The velocity dispersion is attributed to viscous shear relaxation. The model of O'Connell and Budiansky modified by introducing the saturation parameter and a Gaussian distribution of crack aspect ratios is used to interpret the data. A trial and error method is used to estimate the model parameters. The model satisfactorily accounts for the data at high saturation.

Domains: Geophysics [physics.geo-ph]

Azar Khalatbari, Dung Vo-Thanh, Jean-Paul Poirier. Effect of fluid viscosity and saturation on the ultrasonic velocities in a Fontainebleau sandstone. Geophysical Research Letters, 1991, 18 (5), pp.885-888. ⟨10.1029/91GL01067⟩. ⟨insu-01733635⟩