各向异性背景下倾斜裂缝储层的地震波频散和衰减特征

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中图分类号：P631 文献标识码：A DOI：10. 13810/j. cnki. issn. 1000⁃7210. 20240279

Abstract：Underground rocks commonly feature multiscale fractures，which induce fluid motion relative to solid when seismic waves pass through them and thus lead to wave dispersion and attenuation. However，most cur⁃ rent rock physics models assume background media to be isotropic and consider fractures that are horizontally or directionally oriented，often overlooking the elastic properties of rocks with fractures of varying orientations and inclinations across different frequency ranges and less analyzing seismic attenuation caused by fractures. In this regard，this study constructs a rock physics model of fractures oriented in arbitrary directions within a trans⁃ versely isotropic（TI）background. Based on the linear slip fracture model，this study reconstructs the expres⁃ sion form of compliance matrix of fractured rocks for the model under the low ⁃frequency and high⁃frequency limits，constructs the frequency⁃dependent compliance matrix of fractured rocks，and incorporates fluid by using the Gassmann equation to develop a physics model for rocks with inclined fractures under the TI background. Using this model，this study analyzes how fluid ⁃ filled fractured rock velocity and attenuation vary with fre⁃ quency ，fracture inclination and azimuth angle ，and quantitatively assesses the influence of background aniso⁃ tropy on elastic properties of fracture media. The results demonstrate significant impacts of fracture inclination and azimuth angle on velocity and attenuation changes. This study underscores the effects of background aniso⁃ tropy on both velocity and attenuation of fractured rocks，highlighting varying effects across different frequencies. Keywords：rock physics model，fracture，anisotropy，dispersion，attenuation

李林鑫，漆乔木，李小斌，等. 各向异性背景下倾斜裂缝储层的地震波频散和衰减特征［J］. 石油地球物理勘探，2025，60（3）：718‑727.LI Linxin ，QI Qiaomu ，LI Xiaobin ，et al. Seismic dispersion and attenuation of inclined fractured reservoirunder anisotropic background［J］. Oil Geophysical Prospecting ，2025 ，60（3）：718‑727.

0 引言

裂缝在各种岩石中广泛分布，能够提供额外的空间供流体流动，从而显著提高地层的有效渗透性，且对油气的富集起着重要作用[1]。（剩余13606字）