Improved inversion through use of the null space
Improved inversion through use of the null space
复制标题
通过使用零空间改进反演
DOI：
10.1190/1.1444195
复制
发表时间：
1997
期刊：
影响因子：
3.3
通讯作者：
R. Gerhard Pratt
中科院分区：
文献类型：
--
作者：
P. Rowbotham;R. Gerhard Pratt
标准的最小二乘旅行时反演法往往能得到速度场的平滑估计。通过将来自测井、岩心数据和地表地质的关于待成像介质的先验信息结合到反演方案中，可以获得更完整的结果。实现这一点的一种有前途的技术包括将该信息投影到反问题的零空间模型奇异向量上，并将该投影与非零空间贡献包括在一起，以便产生解。通过层状各向异性介质获取的野外和合成井间走时数据证明，该方法成功地产生了比用标准技术获得的解具有更低走时残差、更均匀、更尖锐的界面和更好的相关各向异性参数的改进的反演解。
Standard least-squares traveltime inversion techniques tend to produce smoothed estimates of the velocity field. More complete results can be obtained by incorporating into the inversion scheme a priori information about the media to be imaged, derived from well logs, core data, and surface geology. A promising technique for achieving this involves projecting this information onto the null space model singular vectors of the inverse problem and including this projection with the non-null space contribution in order to produce a solution. The method, demonstrated with both field and synthetic crosshole traveltime data acquired through layered, anisotropic media, successfully produces improved inversion solutions with lower traveltime residuals, layers that are more homogeneous, sharper interfaces, and better correlated anisotropy parameters than solutions obtained with standard techniques.