Effect of Shear Stress on Shear Wave Splitting: A Laboratory Analysis

Abstract

Seismic behavior of shear waves passing through an anisotropic media and related velocity changes and variations are new challenges for geo-researchers. Shear wave splitting which is the main known result of passing the shear waves through an anisotropic media can provide very useful information about the characteristic of the anisotropic medium. In this study, the effects of shear stress on shear wave splitting and characteristic of split components like amplitude and frequency spectrum have been compared on a sample from an oil field in South-West Iran. The results of this ultrasonic test on a carbonate sample show that the amplitude of perpendicular component (Normal to the shear stress direction) will increase when we increase the amount of shear stresses. This may be used to detect the orientation of the anisotropies and/or on the other hand with enough information about the anisotropies some characteristic of stress field may be estimated.
 

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References

[1] Crampin S., “A review of wave motion in anisotropic and cracked elastic media: Wave motion”, Vol. 3, pp. 343-391, 1981.
[2] Crampin S., “Seismic wave propagation through a cracked solid: polarization as a possible dilatancy diagnostic”, Geophys. J. R. Astr. Soc., Vol. 53, pp. 467-496, 1978.
[3] Crampin S., “A review of the effects of anisotropic layering on the propagation of seismic waves”, Geophys. J.R. Astron. Soc., Vol. 49, pp. 9-27, 1977a.
[4] Keith C.M. & Crampin S., “Seismic body waves in anisotropic refraction at a plane interface”, Geophys. J. R.Astron. Soc., Vol. 49, pp. 181-208, 1977a.
[5] Keith C.M. & Crampin S., “Seismic body waves in anisotropic media: propagation through a layer”, Geophys.J. R. Astron. Soc., Vol. 49, pp. 209-223, 1977b.
[6] Keith C.M. & Crampin S., “Seismic body waves in anisotropic media: synthetic seismograms”, Geophys. J. R.Astron. Soc., Vol. 49, pp. 225-243, 1977b.
[7] Crampin S., “Seismic wave propagation through a cracked solid: polarization as a possible dilatancy diagnostic”, Geophys. J. R. Astron. Soc., Vol. 53, pp. 467-496, 1978.
[8] Crampin S. & McGonigle R., “The variation of delays in stress-induced polarization anomalies”, Geophys. J. R.Astron. Soc., Vol. 64, pp. 115-131, 1981.
[9] Crampin S. & Yedlin M., “Shear-wave singularities of wave propagation in anisotropic media”,            J. Geophys., Vol. 49, pp. 43-46, 1981.
[10] Crampin S., Evans R., Doyle M., & Davis J.P., “Comments on papers about shear-wave splitting in dilatancyinduced anisotropy by I. N. Gupta & by A. Ryall & W. U. Savage”, Bull. Seism. Soc. Am., Vol. 71, pp. 375-377, 1981.
[11] Mavko G., Mukerji T. & Dvorki J., The Rock Physics Handbook: Tools for seismic Analysis in Porous Media, Cambridge University Press, 2003.
 
Journal of Petroleum Research
Volume 17, Issue 56.1 - Serial Number 56
September and October 2007
Pages 84-92

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