论文详情
实际地下介质具有粘滞性，研究粘声介质下的全波形反演方法具有实际意义。针对全波形反演中Hessian矩阵计算复杂、共轭梯度法收敛速度慢等问题，将修正型FR共轭梯度法应用到全波形反演中。修正型FR共轭梯度法使用了更多的梯度信息，具有和拟牛顿法相似的结构和性质，在加快收敛速度的同时可以提升反演效果，计算量仅有少量增加。采用该方法进行了标准线性固体（SLS）模型的时间域粘声多参数全波形反演的研究。模型测试结果表明相对于常规FR共轭梯度法，修正后的方法可以得到更精确的反演结果，加快收敛速度的同时深部反演效果更好，并通过两步法反演策略进一步提高了品质因子的反演效果。
The real earth media is characterized by the visco-elasticity, and it is of practical importance to study the full waveform inversion method in visco-elastic media. The full waveform inversion (FWI) is used to estimate the subsurface parameters by matching the simulated data obtained by the forward simulation with the actual recorded seismic data, and the optimization algorithm is generally used to solve the problem. To address the problems of complicated Hessian matrix calculation and slow convergence speed of conjugate gradient method in full waveform inversion, the modified FR conjugate gradient method is applied to the full waveform inversion. The modified FR conjugate gradient method uses more gradient information and has similar structure and properties as the quasi-newton algorithm, which makes the convergence more stable while speeding up the convergence speed and needs little more calculation. This paper use this method conduct a study of the time-domain visco-acoustic multiparameter full waveform inversion under the SLS model. The model test show that the modified method can obtain more accurate inversion results than the conventional FR conjugate gradient method, accelerate the convergence and resolution of deep layer. And the two-step inversion strategy is used to further improve the inversion effect of Q.