Frequency-dependent elastic wave propagation through anisotropic media induced by saturated cracks

被引：1

作者：

Meng H. ^{[1
]}

Wei Z. ^{[2
]}

机构：

[1] Petrochina Hangzhou Research Institute of Geology, 920 Xixi Road, Hangzhou

[2] China University of Petroleum (East China), 66 Changjiang West Road, Qingdao

来源：

Arabian Journal of Geosciences | 2021年 / 14卷 / 19期

基金：

中国国家自然科学基金;

关键词：

Dispersion and attenuation; Frequency dependent; Oriented crack; Squirt flow model;

D O I：

10.1007/s12517-021-07027-0

中图分类号：

学科分类号：

摘要：

Usually, there exist both pores and oriented cracks in real rocks, and the existence of oriented cracks leads to the anisotropy, alters the rock stiffness property, and affects the elastic wave velocities. Besides, the local flow (squirt flow) between pores and cracks is also considered an important factor influencing the elastic wave velocities. In this paper, the frequency-dependent model is derived based on the squirt flow model to describe the elastic wave characteristics in anisotropic media induced by cracks. Through the study of the elastic wave characteristics at different crack parameters, incidence angles, and frequencies, it is found that the increase of crack density decreases the rock stiffness and enhances the effect of squirt flow resulting in the decrease of wave velocities and the increase of the degree of anisotropy, and the change of aspect ratio only influences the dispersion range. Moreover, P-wave velocity is found to be greatly affected by the squirt flow in a direction perpendicular to crack plane, and as the polarization direction is always parallel to crack plane, the fast shear wave is not influenced by squirt flow. Besides, the effect of squirt flow decreases at high frequency, which leads to the increase of the rock stiffness and wave velocities. By applying the frequency-dependent model to a real case, the experimental data can be well-interpreted. © 2021, Saudi Society for Geosciences.

引用

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