叠前AVA广义非线性纵、横波速度反演

Generalized non-linear P wave and S wave velocity inversion of prestack AVA.

利用叠前 AVA地震资料反演地下介质的纵、横波速度 ,可以为地层岩性、储层物性及含油气性解释提供丰富的弹性参数信息。本文以 Aki和 Richards近似公式为基础 ,将最小平方问题转化为大型稀疏矩阵的求解问题 ,直接反演出纵、横波速度 ;根据建立的反演目标函数导出了广义非线性矩阵反演方程 ;噪声协方差矩阵和模型协方差矩阵的加入 ,使叠前反演稳定性增强 ;通过 AVA合成记录标定、AVA反演子波估算以及测井、构造层位信息的共同约束 ,有效地降低了反演的多解性问题。理论模型试算和实际资料处理结果均表明 ,该方法处理效果良好。

Using prestack AVA seismic data for inversi- on of underground P wave and S wave velocities can provide abundant elastic parameters for interpretation of stratigraphic lithology,physical nature of reservoir and oil-bearing characters.Based on approximate formula presented by Mr.Aki and Richards,the paper transforms the least square issues into finding the solution of large-scale sparse matrix,directly makes the inversion of P wave and S wave velocities;deduces generalized non-linear matrix inversion equations based on built inversional object function;adding covariance matrix of noises and covariance of model can improve the stability of prestack inversion;joint constraints by labeling of AVA synthetic records,evaluation of AVA inversion wavelet and logging and structural beds information can effectively reduce the issue of multiple solutions of inversion.Theoretical models test and real data processing showed that the method has good processed results.