Two-term AVO inversion: Equivalences and new methods
Two-term AVO inversion: Equivalences and new methods
复制标题
两项 AVO 反演：等价项和新方法
DOI：
10.1190/1.2978388
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发表时间：
2008
期刊：
影响因子：
3.3
通讯作者：
R. Stewart
中科院分区：
文献类型：
--
作者：
C. Ursenbach;R. Stewart
大多数振幅随偏移量变化（AVO）研究都使用双参数反演方法，这是基于Aki-Richards近似的更一般的三参数方法的近似。由于三参数反演常受数值不稳定性的困扰，双参数方法得到了广泛的应用。降低参数空间的维数使反演稳定。各种约束条件都可以实现这一点，这导致了当前双参数方法的多样性。理解各种双参数方法之间的关系是很有用的。为此，我们推导了每种方法反演误差的形式表达式。利用这些表达式，得到了可以灵活地将任意两参数方法的结果转换为任意其他两参数方法的结果的转换公式。方法等价的唯一要求是最大入射角至少比临界角小几度。此外，误差表达式导致双参数AVO工具的新公式，该工具结合了两种常用方法的优点。这些表达式还提供了一种将测井校准信息整合到传统AVO反演中的简单方法。这些结果对资源勘探具有一定的指导意义。
Most amplitude-variation-with-offset (AVO) studies use two-parameter inversion methods that are approximations of a more general three-parameter method based on the Aki-Richards approximation. Two-parameter methods are popular because the three-parameter inversion is often plagued by numerical instability. Reducing the dimensionality of the parameter space stabilizes the inversion. A variety of constraints can accomplish this, and these lead to the multiplicity of current two-parameter methods. It would be useful to understand relationships between various two-parameter methods. To this end, we derive formal expressions for inversion errors of each method. Using these expressions, conversion formulas are obtained that allow the flexibility to convert results of any two-parameter method to those of any other two-parameter method. The only requirement for the equivalence of methods is that the maximum angle of incidence be at least a few degrees less than the critical angle. In addition, error expressions result in a new formulation for a two-parameter AVO tool that combines strengths of two commonly used methods. The expressions also suggest a simple way to incorporate information from well-log calibration into legacy AVO inversions. These results should be helpful in resource exploration.