Forced oscillation measurements of seismic attenuation in fluid saturated sandstone
Adopting the method of forced oscillation, attenuation was studied in Fontainebleau sandstone (porosity 10%, permeability 10 mD) at seismic frequencies (1–100 Hz). Confining pressures of 5, 10, and 15 MPa were chosen to simulate reservoir conditions. First, the strain effect on attenuation was investigated in the dry sample for 11 different strains across the range 1 × 10−6–8 × 10−6, at the confining pressure of 5 MPa. The comparison showed that a strain of at least 5 × 10−6 is necessary to obtain a good signal to noise ratio. These results also indicate that nonlinear effects are absent for strains up to 8 × 10−6. For all the confining pressures, attenuation in the dry rock was low, while partial (90%) and full (100%) saturation with water yielded a higher magnitude and frequency dependence of attenuation. The observed high and frequency dependent attenuation was interpreted as being caused by squirt flow.
KeywordsForced oscillation Sandstone Strain Attenuation
Petrobras co-funded this project. We would like to thank Claudio Madonna for his support in the laboratory and Prof. Jean-Pierre Burg for providing a conducive research environment.
- Carcione JM (2007) Wave fields in real media: theory and numerical simulation of wave propagation in anisotropic. Anelastic porous and electromagnetic media. Elsevier, AmsterdamGoogle Scholar
- Chapman S, Tisato N, Quintal B, Holliger K (2016) Seismic attenuation in partially saturated Berea sandstone submitted to a range of confining pressures. J Geophys Res Solid Earth 121(3):1664–1676. doi: 10.1002/2015JB012575
- Mikhaltsevitch V, Lebedev M, Gurevich B (2014) A laboratory study of low-frequency wave dispersion and attenuation in water-saturated sandstones. Leading Edge 33(6):616–618, 620–622. doi: 10.1190/tle33060616.1
- Tisato N, Quintal B (2014) Laboratory measurements of seismic attenuation in sandstone: strain versus fluid saturation effects. Geophysics 79(5):WB9–WB14. doi: 10.1190/geo2013-0419.1
- Zimmerman RW (1991) Compressibility of sandstones, developments in petroleum science, vol 29. Elsevier Science Publishing Co., Inc., New YorkGoogle Scholar