叠前地震数据弹性参数反演及反演策略浅析

Inversion for elastic parameters using pre-stack seismic data and analysis on inversion strategy

反演本质上具有不适定性,在反演过程中采用一定的策略很有必要.本文采用反射率法正演、共轭梯度法反演的正反演体系,从不同频带数据的最佳收敛步长、目标函数的组成等方面对反演的影响进行了探讨.在此基础上采用分频反演、分层反演及变权重目标函数的策略,利用海上测井弹性参数模型对地震叠前波形数据进行了弹性参数反演试验.通过对反演结果的分析指出对反演的中间结果进行质量评估和质量控制的必要性.

The inverse problem is ill-posed essentially, so the inversion strategy is very important in order to obtain reasonable inversion result. In this paper, the modeling and inversion system of refleetivity and conjugate gradient method is taken. The influences are discussed which the best convergence step of data with different frequency range and the composition of objective function have imposed on the inversion. The strategies of layer-divided inversion, frequency-divided inversion and varied objective function are taken based on the discussion, and the test of inversion for elastic parameters is done using pre-stack seismic data and marine logging model. The point of view is proposed that it is necessary to control the quality of inversion intermediate results in order to obtain stable and reasonable inversion final solution, based on the analysis on the inversion result.