基于反射界面自动拾取的AVA反演方法研究

本文将逐点匹配滤波思想应用于叠前AVA反演,提出了一种反射界面自动拾取方法,从而将叠前非线性反演问题转化为两步线性反演进行求解.首先基于逐点计算的方式获取每个采样点对应的残差值,然后在残差曲线上自动拾取波谷以定位反射界面,最后在频率域采用最小二乘反演对叠前参数进行更准确的估计.相比于传统的同时估计反射界面位置和幅值的非线性反演方法,该方法不需要关于参数的个数、分布等先验假设,并且具有运算速度快、求解稳定的优点.模型试验以及实际地震资料处理验证了该方法的有效性.

AVA inversion based on automatic picking-up of reflection interfaces

The idea of matched filtering in a sample-by-sample way is applied to prestack AVA inversion and an automatic method for reflection interfaces picking is proposed, which permits to transform the nonlinear prestack inversion into a two-step linear inversion. First, the residuals corresponding to all samples are calculated sample-by-sample.Then reflection interfaces are located automatically by picking up the troughs on the residual curve. Finally, the intercepts and gradients are estimated with the least-squares inversion in the frequency domain.Compared with the traditional methods to simultaneously invert for locations and amplitudes of reflections, the proposed method has higher computation efficiency and better stability and does not need some prior constraints such as the distribution or the number of the parameters.Synthetic examples and experiments on field data validate the feasibility of this method.