Laboratory measurements of low- and high-frequency elastic moduli in Fontainebleau sandstone

Emmanuel C. David, Jérome Fortin, Alexandre Schubnel, Yves Guéguen, Robert W. Zimmerman
2013 Geophysics  
The presence of pores and cracks in rocks causes the fluid-saturated wave velocities in rocks to be dependent on frequency. New measurements of the bulk modulus at low frequencies (0.02-0.1 Hz) were obtained in the laboratory using oscillation tests carried out on two hydrostatically stressed Fontainebleau sandstone samples, in conjunction with ultrasonic velocities and static measurements, under a range of differential pressures (10-95 MPa), and with three different pore fluids (argon,
more » ... ids (argon, glycerin, and water). For the 13% and 4% porosity samples, under glycerin-and watersaturated conditions, the low-frequency bulk modulus at 0.02 Hz matched well the low-frequency and ultrasonic dry bulk modulus. The glycerin-and water-saturated samples were much more compliant at low frequencies than at high frequencies. The measured bulk moduli of the tested rocks at low frequencies (0.02-0.1 Hz) were much lower than the values predicted by the Gassmann equation. The frequency dispersion of the P and S velocities was much
doi:10.1190/geo2013-0070.1 fatcat:ooeeajig3jhdtkwopdkdor7yea