Dispersion and Attenuation of Elastic Wave Velocities: Impact of Microstructure Heterogeneity and Local Measurements
| Autor: | Chao Sun, Jan V. M. Borgomano, Genyang Tang, Shangxu Wang, Jérôme Fortin |
|---|---|
| Přispěvatelé: | China University of Petroleum, Laboratoire de géologie de l'ENS (LGENS), Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Département des Géosciences - ENS Paris, École normale supérieure - Paris (ENS Paris), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-École normale supérieure - Paris (ENS Paris), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL) |
| Rok vydání: | 2020 |
| Předmět: |
seismic properties
Materials science 010504 meteorology & atmospheric sciences [SDU.STU.GP]Sciences of the Universe [physics]/Earth Sciences/Geophysics [physics.geo-ph] dual-scale fluid-flow model Attenuation Flow (psychology) low-frequency measurement Mechanics Microstructure 01 natural sciences Aspect ratio (image) global flow and local flow Geophysics Space and Planetary Science Geochemistry and Petrology Earth and Planetary Sciences (miscellaneous) Range (statistics) dispersion Dispersion (water waves) Porosity attenuation Strain gauge 0105 earth and related environmental sciences |
| Zdroj: | Journal of Geophysical Research : Solid Earth Journal of Geophysical Research : Solid Earth, American Geophysical Union, 2020, ⟨10.1029/2020JB020132⟩ |
| ISSN: | 2169-9356 2169-9313 |
| Popis: | International audience; The variation of the seismic properties with frequency of a brine-saturated sandstone sample with a porosity of 22% was measured using a forced oscillation apparatus. Two pairs of orthogonal biaxial strain gauges were pasted at different locations at the length center of the sample. In the frequency range of 1-300 Hz, using these two pairs of strain gauges, we observed experimentally the same global flow but different local flows (squirt flow). Therefore, the observation of the local flow is influenced by the position of the strain gauges in contrast to the global flow. Indeed, local flow is strongly influenced by the microstructure (structure of the grain contacts and microcracks). In particular, we show that although the sample is homogeneous in terms of porosity and crack density, it is not the case in terms of crack aspect ratio, which may slightly vary along the sample. A 3D diffusion model coupled with a simple squirt model was built to further interpret the data. These results show that the wave-induced fluid flows occur at different scales and controls the dispersion and attenuation of saturated rocks. |
| Databáze: | OpenAIRE |
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