基于拟牛顿法频率域全波形反演研究

全波形反演是综合利用地震波场的运动学和动力学参数,通过最小二乘来拟合实际波场和预测波场,从而获得地质结构和岩性资料的方法。本文先简述了频率域地震波正演,之后利用拟牛顿法来推导频率域全波形反演,克服了高斯——牛顿法中海森矩阵可能奇异或者非正定特性,通过图形对比,得到频率域全波形反演局限在于频率的缺失和来自其它地质结构对三维地质模型受到的影响比较大,合理选择频点和频宽进行反演可解决频率缺失的影响,二维地质模型的反演效果理想,而三维地质模型的反演有待提高和改进。

Frequency Domain Full Waveform Inversion Study Based on Quasi-Newton Method

Full waveform inversion is a method that comprehensively using kinematic and kinetic parameters of the seismic wave field, fitting the actual wave field and predicting the wave field by least squares to obtain the geological structure and lithology information. This paper first outlines the frequency domain seismic forward, then uses quasi-Newton method to derive the frequency domain full waveform inversion, overcomes the possible singular or non-positive definite in Gauss-Newton method, through a graphical comparison, gets that frequency domain full waveform inversion limited by the deletions of frequency and other geological structures have great impact on three-dimensional geological model, legitimately selects frequency and bandwidth for inversion can resolves the missing influence of frequency. The two-dimensional geological model had good inversion effect, while the three-dimensional geological inversion model needs to be improved and improved.