Abstract
Based on Hudson’s theoretical hypothesis of equivalent fracture model, inserting aligned round chips in solid model can simulate fractured media. The effect of fractures on the propagation of P and S waves can be observed by changing the fracture thickness. The base model is made of epoxy resin, and the material of fractures is a kind of low-velocity mixture containing silicon rubber. With constant diameter and number of fractures in each model, one group of models can be formed through changing the thickness of fracture. These models have the same fracture density. By using the ultrasonic pulse transmission method, the experiment records time and waveform of P and S waves in the direction parallel and perpendicular to the fracture orientation. The result shows that, with the same fracture density, changing fracture aperture will affect both velocity and amplitude of P and S waves, and the effect on P-wave amplitude is much greater than that on the velocity. Moreover, the variation in velocity of S wave is more obvious in the slow shear wave (S2), while the variation in amplitude is more obvious in the fast shear wave (S1). These properties of wave propagation are useful for seismic data processing and interpretation.
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References
Hudson J A. Overall properties of a cracked solid. Math Proc Camb Phil Soc, 1980, 88: 371–384
Hudson J A. Wave speeds and attenuation of elastic waves in material containing cracks. Geophys J Roy Astr Soc, 1981, 64: 133–150
Chichinina T, Sabinin V, Ronquillo-Jarillo G. P-wave attenuation anisotropy in fracture characterization: Numerical modeling for reflection data. 74th Annual International Meeting, SEG, Expanded Abstracts, 2004. 143–146
Zhu Y, Tsvankin I. Plane-wave propagation in attenuative transversely isotropic media. Geophysics, 2006, 71(2): T17–T30
Tatham R H, Matthews M D, Sekharan K K, et al.A physical model study of shear-wave splitting and fracture intensity. Geophysics, 1992, 57(4): 647–652
Ebrom D A, Tatham R H, Sekharan K K, et al. Hyperbolic travel time analysis of first arrivals in an azimuthally anisotropic medium: A physical model study. Geophysics, 1990, 55: 185–191
Schoenberg M, Douma J. Elastic wave propagation in media with parallel fractures and aligned cracks. Geophys Prosp, 1988, 36: 571–590
He Z, Li Y, Zhang F, et al. The effect of directional fractures on seismic velocity and amplitude (in Chinese). Tech Phys Chem Comput, 2001, 23(1): 1–5
Ass’ad J M, Tatham R H, McDonald J A. A physical model study of microcrack-induced anisotropy. Geophysics, 1992, 57(12): 1562–1570
Ass’ad J M, Tatham R H, McDonald J A, et al. A physical model study of scattering of waves by aligned cracks: Comparison between experiment and theory. Geophys Prosp, 1993, 41: 323–341
Rathore J S, Fjaer E, Holt R M, et al.P- and S-wave anisotropy of a synthetic sandstone with controlled crack geometry. Geophys Prosp, 1995, 43(6): 711–728
Jianxin W, Chunyong W. Experiment on shear wave observation in anisotropy medium (in Chinese). Geophys Prosp Petrol, 2004, 43(5): 427–432
Jianxin W. A physical model study of different crack densityes. J Geophys Eng, 2004, 1((1): 70–76
Cheadle S P, Brown J, Lawton D C. Orthorhombic anisotropy: A physical seismic modeling study. Geophysics, 1991, 56: 1603–1613
Isaac J H, Lawton D C. Image mispositioning due to dipping TI media: A physical seismic modeling study. Geophysics, 1999, 64: 1230–1238
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Supported by the Major State Basic Research Development Program of China (973 Project) (Grant No. 2006CB202306) and the Applied Basic Project of China National Petroleum Corporation (Grant No. 200510101)
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Wei, J., Di, B. A physical model study of effect of fracture aperture on seismic wave. Sci. China Ser. D-Earth Sci. 51 (Suppl 2), 233–240 (2008). https://doi.org/10.1007/s11430-008-6005-x
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DOI: https://doi.org/10.1007/s11430-008-6005-x