Frquency-domain Elastic Waveform Inversion With Irregular Surface Topography
Frquency-domain Elastic Waveform Inversion With Irregular Surface Topography
复制标题
不规则表面形貌频域弹性波形反演
DOI：
10.1190/1.3059291
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发表时间：
2008
期刊：
影响因子：
--
通讯作者：
C. Shin
中科院分区：
文献类型：
--
作者：
U. Jang;D. Min;Yunseok Choi;C. Shin
为了描述陆基地震勘探中常见的不规则地形，我们提出了一种针对这种现象的频域弹性波建模算法，并将其纳入弹性波形反演算法中。我们使用有限元方法进行建模和反演算法，其中主体由矩形单元近似，不规则地形由三角形单元描述。与传统的有限元建模算法一样，我们的有限元不规则地形建模算法也自然地满足由于诺依曼边界条件而产生的自由表面边界条件，在构建有限元公式时将其纳入其中。对于反演算法，我们使用最速下降法，并使用伪 Hessian 矩阵的对角线而不是近似或完整 Hessian 矩阵来缩放梯度方向。我们将反演技术应用于 SEG/EAGE 盐丘模型的 AA 线，并进行修改以考虑不规则的表面形貌。通过数值例子，我们证明了我们的弹性波形反演可以很好地再现地下结构和弹性参数，即使对于具有不规则地形的模型也是如此。
In order to describe the irregular topography that is commonly encountered in land-based seismic exploration, we present a frequency-domain elastic wave modeling algorithm for this phenomenon, incorporated into an elastic waveform inversion algorithm. We use a finite-element method, both for the modeling and for the inversion algorithms, in which the main body is approximated by rectangular elements and irregular topography is described by triangular elements. In common with conventional finite-element modeling algorithms, our finiteelement irregular topography modeling algorithm also naturally satisfies the free-surface boundary condition due to the Neumann boundary condition, which is incorporated when we construct the finite-element formulae. For the inversion algorithm, we use the steepest-descent method, and scale the gradient direction using the diagonal of the pseudo-Hessian matrix rather than the approximate or full Hessian matrix. We apply the inversion technique to the AA-line of the SEG/EAGE salt dome model, modified to account for irregular surface topography. Through numerical examples, we demonstrate that our elastic waveform inversion can reproduce subsurface structures and elastic parameters fairly well, even for a model with irregular topography.
影响因子：
3
作者：
T. Ichimura;M. Hori;Hiroyuki Kuwamoto
通讯作者：
T. Ichimura;M. Hori;Hiroyuki Kuwamoto