We present a workflow for computing seismic wave moduli dispersion and attenuation due to squirt flow on a numerical model derived from X-Ray micro-Computed Tomography (μXRCT) images. We imaged, segmented and meshed a sub-volume of a rock sample. Then finite element method is adopted to solve the linearized, quasi-static Navier-Stokes equations describing laminar flow of a compressible viscous fluid inside the cracks and pores coupled with the quasistatic Lamé-Navier equations for the solid phase. A thermally treated (thus cracked) Carrara marble sample was employed, and we consider it fully saturated with glycerin due to its high viscosity. We compute the effective P-wave modulus dispersion and attenuation in the spatial domain of the sub-volume. We compare the results of two numerical models, derived from the same sub-volume, having different degrees of crack walls roughness associated with the segmentation process. Our results show that the roughness in the crack walls increases attenuation at lower frequencies due to the contribution of smaller crack apertures.
Presentation Date: Wednesday, October 14, 2020
Session Start Time: 8:30 AM
Presentation Time: 8:55 AM
Presentation Type: Oral