Imaging conditions for elastic reverse time migration
Imaging conditions for elastic reverse time migration
复制标题
弹性逆时偏移成像条件
DOI：
10.1190/geo2018-0197.1
复制
发表时间：
2019-03
期刊：
影响因子：
3.3
通讯作者：
Ying Shi
中科院分区：
文献类型：
--
作者：
Wei Zhang;Ying Shi
弹性逆时偏移（RTM）能够通过对多分量地震数据成像，精确地恢复复杂地下构造的偏移图像。然而，成像条件施加在弹性RTM显着影响偏移图像的质量。我们评价了三种弹性RTM成像条件。第一种成像条件涉及粒子速度波场的笛卡尔分量之间的互相关，以产生地下结构的偏移图像。一个替代的互相关成像条件之间的分离的纯波模式得到的亥姆霍兹分解方法可以产生反射率图像具有明确的物理意义和较少的串扰伪影。然而，这种方法的一个缺点是，分离的S波的极性反转可能会在多次激发叠加后在转换波图像中引起相消干扰。与传统的分解方法不同，弹性波场也可以在矢量域中使用解耦的弹性波方程进行分解，这保留了原始弹性波场的振幅和相位信息。我们已经开发了一个内积成像条件，以匹配矢量分离的P波和S波模式，以获得地下标量反射率图像。此外，辅助P波应力图像可以补充弹性成像。通过对层状模型、Marmousi 2模型和断层模型的综合实例，确定了内积成像条件优于其他两种成像条件，并生成了保留振幅和相位属性的图像。
Elastic reverse time migration (RTM) has the ability to retrieve accurately migrated images of complex subsurface structures by imaging the multicomponent seismic data. However, the imaging condition applied in elastic RTM significantly influences the quality of the migrated images. We evaluated three kinds of imaging conditions in elastic RTM. The first kind of imaging condition involves the crosscorrelation between the Cartesian components of the particle-velocity wavefields to yield migrated images of subsurface structures. An alternative crosscorrelation imaging condition between the separated pure wave modes obtained by a Helmholtz-like decomposition method could produce reflectivity images with explicit physical meaning and fewer crosstalk artifacts. A drawback of this approach, though, was that the polarity reversal of the separated S-wave could cause destructive interference in the converted-wave image after stacking over multiple shots. Unlike the conventional decomposition method, the elastic wavefields can also be decomposed in the vector domain using the decoupled elastic wave equation, which preserves the amplitude and phase information of the original elastic wavefields. We have developed an inner-product imaging condition to match the vector-separated P- and S-wave modes to obtain scalar reflectivity images of the subsurface. Moreover, an auxiliary P-wave stress image can supplement the elastic imaging. Using synthetic examples with a layered model, the Marmousi 2 model, and a fault model, we determined that the inner-product imaging condition has prominent advantages over the other two imaging conditions and generates images with preserved amplitude and phase attributes.
登录
查看更多内容
DOI：
10.1190/1.1822300
发表时间：
1993
期刊：
Seg Technical Program Expanded Abstracts
影响因子：
--
作者：
Toru Takahashi
通讯作者：
Toru Takahashi
影响因子：
3.3
作者：
Y. Duan;P. Sava
通讯作者：
Y. Duan;P. Sava
影响因子：
--
作者：
R. Wu
通讯作者：
R. Wu
DOI：
10.1190/1.2370059
发表时间：
2006
期刊：
Seg Technical Program Expanded Abstracts
影响因子：
--
作者：
B. Kaelin;A. Guitton
通讯作者：
B. Kaelin;A. Guitton
影响因子：
3.3
作者：
Qunshan Zhang;G. McMechan
通讯作者：
Qunshan Zhang;G. McMechan