论文部分内容阅读
当存在大量的反射层时,用Cohen和Bleistein1979年提出的线性速度反演方法,所得的结果很差。这种线性算法用于非线性的地质体时,信息就会有明显的损失。但在许多情况下,通过对基本线性反演算法输出进行适当的后处理,可以得到极好的结果。虽然直接进行线性化处理可在一定程度上有助于后处理,但我们还要介绍一种已作本质上改进的后处理算法。这种改进算法的基础是一种较为精确的散射模型,因为Lahlou等(其中包括波动方程的WKB分析)对散射波几何扩散都获得过精确得多的计算。这些理论加上旅行时的有效应用都可用于这个新算法,这样既能改善对反射层位置的估算,又能进行各反射层振幅(速度或波阻抗)变化的估算.基本想法是在原始的线性算法中引入理想化的散射资料,所以这一计算结果可用作这种算法数字输出解释的指导。我们用有噪声和无噪声的合成资料,验证了这种算法计算机运算结果,并证明了这种后处理算法可明显改进反射层位和速度估算。此处,这种算法只需在基本处理的基础上增加非常少的费用:换句话说,与其它多维算法相比,其费用较为节省.
When there are a large number of reflective layers, the results are poor with the presence of an impedance profile developed by Cohen and Bleistein in 1979. This linear algorithm for non-linear geological body, the information will have a significant loss. However, in many cases, excellent results can be obtained by proper post-processing of the output of the basic linear inversion algorithm. Although direct linearization can contribute to postprocessing to some extent, we also introduce an essentially improved postprocessing algorithm. The basis of this improved algorithm is a more accurate scattering model, as Lahlou et al. (Which includes WKB analysis of wave equations) obtain much more accurate calculations of scattered wave geometry. These theories, combined with travel-time valid applications, can be used in this new algorithm to both improve the estimation of the reflector’s position and to estimate the change in the amplitude (velocity or impedance) of the reflector. The basic idea is that in the original Linear algorithms introduce idealized scatter data, so this result can be used as a guide to interpret the digital output of this algorithm. Using noise and noise-free synthetic data, we verify the results of computer algorithms and prove that this post-processing algorithm can significantly improve the reflection horizon and velocity estimation. Here, the algorithm only adds very little cost to the basic processing: in other words, it is more cost-effective than other multi-dimensional algorithms.