Analysis of S waves singularity points in porous rock with two orthogonal sets of mesoscale fractures. Issue 1 (7th September 2021)

• Record Type: Journal Article
• Authors: Pang, Shuo; Stovas, Alexey; Xing, Huilin
• Is Part Of: Geophysical journal international. Volume 228:Issue 1(2022)
• Page Start: 604
• Page End: 619
• Publication Date: 2021-09-07
• Subjects: Elasticity and anelasticity -- Fracture and flow -- Wave propagation; Geophysics -- Periodicals; 550
• DOI: 10.1093/gji/ggab362
• Languages: English
• ISSNs: 0956-540X

Abstract

SUMMARY: The shear waves phase velocity surfaces in orthorhombic (ORT) and lower symmetry anisotropic models touch each other in one or more points resulting in so called singularity points or acoustic axes. These singularity points result in dramatic changes of velocities, amplitudes and polarizations creating problems in seismic data processing and analysis. Considering the frequency-dependent anisotropy due to mesoscale fractures in Chapman's model, we describe the singularity points in porous rock with two orthogonal sets of mesoscale fractures. First, we give the equations for frequency-dependent phase velocities of P, S 1 and S 2 waves in this anelastic ORT media. Then, we derive the expressions for frequency-dependent singularity points within the symmetry planes and discuss the conditions to detect the existence of singularity point. Finally, the influences of frequency, porosity, fracture density, fracture scale and saturating fluid style on the positions of singularity points within the symmetry plane are investigated.