Estimation of fracture parameters from reflection seismic data—Part III: Fractured models with monoclinic symmetry
Estimation of fracture parameters from reflection seismic data—Part III: Fractured models with monoclinic symmetry
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DOI：
10.1190/1.1444864
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发表时间：
2000-11
期刊：
影响因子：
3.3
通讯作者：
A. Bakulin;V. Grechka;I. Tsvankin
中科院分区：
文献类型：
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作者：
A. Bakulin;V. Grechka;I. Tsvankin
现有的地球物理和地质资料表明，具有水平对称面的正交介质在天然裂缝性储层中应该是相当普遍的。在这里，我们考虑两个正交模型：一个包含平行的垂直裂缝嵌入在横向各向同性的背景与垂直对称轴（VTI介质），另一个由两组正交的旋转不变的垂直裂缝在一个纯粹的各向同性的寄主岩石形成。利用线性滑移理论，我们得到了有效正交介质各向异性系数的简单解析表达式。在弱各向异性的背景介质（对于第一个模型）和小的裂缝的顺应性的假设下，所有有效的各向异性参数减少到与每个裂缝组相关联的背景值和参数的总和。对于单裂隙系统的模型，这一结果使我们能够通过评估VTI背景与裂隙系统之间的差异来消除VTI背景的影响。
Existing geophysical and geological data indicate that orthorhombic media with a horizontal symmetry plane should be rather common for naturally fractured reservoirs. Here, we consider two orthorhombic models: one that contains parallel vertical fractures embedded in a transversely isotropic background with a vertical symmetry axis (VTI medium) and the other formed by two orthogonal sets of rotationally invariant vertical fractures in a purely isotropic host rock. Using the linear‐slip theory, we obtain simple analytic expressions for the anisotropic coefficients of effective orthorhombic media. Under the assumptions of weak anisotropy of the background medium (for the first model) and small compliances of the fractures, all effective anisotropic parameters reduce to the sum of the background values and the parameters associated with each fracture set. For the model with a single fracture system, this result allows us to eliminate the influence of the VTI background by evaluating the differences between t...